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			6412 lines
		
	
	
		
			164 KiB
		
	
	
	
		
			Diff
		
	
	
	
	
	
			
		
		
	
	
			6412 lines
		
	
	
		
			164 KiB
		
	
	
	
		
			Diff
		
	
	
	
	
	
| This patch adds support for bfs v230, modified for diff size reduction
 | |
| 
 | |
| --- a/Documentation/sysctl/kernel.txt
 | |
| +++ b/Documentation/sysctl/kernel.txt
 | |
| @@ -27,6 +27,7 @@ show up in /proc/sys/kernel:
 | |
|  - domainname
 | |
|  - hostname
 | |
|  - hotplug
 | |
| +- iso_cpu
 | |
|  - java-appletviewer           [ binfmt_java, obsolete ]
 | |
|  - java-interpreter            [ binfmt_java, obsolete ]
 | |
|  - kstack_depth_to_print       [ X86 only ]
 | |
| @@ -48,6 +49,7 @@ show up in /proc/sys/kernel:
 | |
|  - randomize_va_space
 | |
|  - real-root-dev               ==> Documentation/initrd.txt
 | |
|  - reboot-cmd                  [ SPARC only ]
 | |
| +- rr_interval
 | |
|  - rtsig-max
 | |
|  - rtsig-nr
 | |
|  - sem
 | |
| @@ -170,6 +172,16 @@ Default value is "/sbin/hotplug".
 | |
|  
 | |
|  ==============================================================
 | |
|  
 | |
| +iso_cpu: (BFS only)
 | |
| +
 | |
| +This sets the percentage cpu that the unprivileged SCHED_ISO tasks can
 | |
| +run effectively at realtime priority, averaged over a rolling five
 | |
| +seconds over the -whole- system, meaning all cpus.
 | |
| +
 | |
| +Set to 70 (percent) by default.
 | |
| +
 | |
| +==============================================================
 | |
| +
 | |
|  l2cr: (PPC only)
 | |
|  
 | |
|  This flag controls the L2 cache of G3 processor boards. If
 | |
| @@ -322,6 +334,19 @@ rebooting. ???
 | |
|  
 | |
|  ==============================================================
 | |
|  
 | |
| +rr_interval: (BFS only)
 | |
| +
 | |
| +This is the smallest duration that any cpu process scheduling unit
 | |
| +will run for. Increasing this value can increase throughput of cpu
 | |
| +bound tasks substantially but at the expense of increased latencies
 | |
| +overall. This value is in milliseconds and the default value chosen
 | |
| +depends on the number of cpus available at scheduler initialisation
 | |
| +with a minimum of 6.
 | |
| +
 | |
| +Valid values are from 1-5000.
 | |
| +
 | |
| +==============================================================
 | |
| +
 | |
|  rtsig-max & rtsig-nr:
 | |
|  
 | |
|  The file rtsig-max can be used to tune the maximum number
 | |
| --- a/include/linux/init_task.h
 | |
| +++ b/include/linux/init_task.h
 | |
| @@ -119,9 +119,10 @@ extern struct cred init_cred;
 | |
|  	.usage		= ATOMIC_INIT(2),				\
 | |
|  	.flags		= PF_KTHREAD,					\
 | |
|  	.lock_depth	= -1,						\
 | |
| -	.prio		= MAX_PRIO-20,					\
 | |
| +	.prio		= NORMAL_PRIO,					\
 | |
|  	.static_prio	= MAX_PRIO-20,					\
 | |
| -	.normal_prio	= MAX_PRIO-20,					\
 | |
| +	.normal_prio	= NORMAL_PRIO,					\
 | |
| +	.deadline	= 0,						\
 | |
|  	.policy		= SCHED_NORMAL,					\
 | |
|  	.cpus_allowed	= CPU_MASK_ALL,					\
 | |
|  	.mm		= NULL,						\
 | |
| --- a/include/linux/sched.h
 | |
| +++ b/include/linux/sched.h
 | |
| @@ -36,9 +36,12 @@
 | |
|  #define SCHED_FIFO		1
 | |
|  #define SCHED_RR		2
 | |
|  #define SCHED_BATCH		3
 | |
| -/* SCHED_ISO: reserved but not implemented yet */
 | |
| +#define SCHED_ISO		4
 | |
|  #define SCHED_IDLE		5
 | |
|  
 | |
| +#define SCHED_MAX		(SCHED_IDLE)
 | |
| +#define SCHED_RANGE(policy)	((policy) <= SCHED_MAX)
 | |
| +
 | |
|  #ifdef __KERNEL__
 | |
|  
 | |
|  struct sched_param {
 | |
| @@ -1042,10 +1045,13 @@ struct sched_entity {
 | |
|  	struct load_weight	load;		/* for load-balancing */
 | |
|  	struct rb_node		run_node;
 | |
|  	struct list_head	group_node;
 | |
| +#ifdef CONFIG_SCHED_CFS
 | |
|  	unsigned int		on_rq;
 | |
|  
 | |
|  	u64			exec_start;
 | |
| +#endif
 | |
|  	u64			sum_exec_runtime;
 | |
| +#ifdef CONFIG_SCHED_CFS
 | |
|  	u64			vruntime;
 | |
|  	u64			prev_sum_exec_runtime;
 | |
|  
 | |
| @@ -1096,6 +1102,7 @@ struct sched_entity {
 | |
|  	/* rq "owned" by this entity/group: */
 | |
|  	struct cfs_rq		*my_q;
 | |
|  #endif
 | |
| +#endif
 | |
|  };
 | |
|  
 | |
|  struct sched_rt_entity {
 | |
| @@ -1123,17 +1130,19 @@ struct task_struct {
 | |
|  
 | |
|  	int lock_depth;		/* BKL lock depth */
 | |
|  
 | |
| -#ifdef CONFIG_SMP
 | |
| -#ifdef __ARCH_WANT_UNLOCKED_CTXSW
 | |
|  	int oncpu;
 | |
| -#endif
 | |
| -#endif
 | |
| -
 | |
|  	int prio, static_prio, normal_prio;
 | |
|  	unsigned int rt_priority;
 | |
|  	const struct sched_class *sched_class;
 | |
|  	struct sched_entity se;
 | |
|  	struct sched_rt_entity rt;
 | |
| +	unsigned long deadline;
 | |
| +#ifdef CONFIG_SCHED_BFS
 | |
| +	int load_weight;	/* for niceness load balancing purposes */
 | |
| +	int first_time_slice;
 | |
| +	unsigned long long timestamp, last_ran;
 | |
| +	unsigned long utime_pc, stime_pc;
 | |
| +#endif
 | |
|  
 | |
|  #ifdef CONFIG_PREEMPT_NOTIFIERS
 | |
|  	/* list of struct preempt_notifier: */
 | |
| @@ -1156,6 +1165,9 @@ struct task_struct {
 | |
|  
 | |
|  	unsigned int policy;
 | |
|  	cpumask_t cpus_allowed;
 | |
| +#ifdef CONFIG_HOTPLUG_CPU
 | |
| +	cpumask_t unplugged_mask;
 | |
| +#endif
 | |
|  
 | |
|  #ifdef CONFIG_PREEMPT_RCU
 | |
|  	int rcu_read_lock_nesting;
 | |
| @@ -1446,11 +1458,19 @@ struct task_struct {
 | |
|   * priority to a value higher than any user task. Note:
 | |
|   * MAX_RT_PRIO must not be smaller than MAX_USER_RT_PRIO.
 | |
|   */
 | |
| -
 | |
| +#define PRIO_RANGE		(40)
 | |
|  #define MAX_USER_RT_PRIO	100
 | |
|  #define MAX_RT_PRIO		MAX_USER_RT_PRIO
 | |
| -
 | |
| +#ifdef CONFIG_SCHED_BFS
 | |
| +#define MAX_PRIO		(MAX_RT_PRIO + PRIO_RANGE)
 | |
| +#define ISO_PRIO		(MAX_RT_PRIO)
 | |
| +#define NORMAL_PRIO		(MAX_RT_PRIO + 1)
 | |
| +#define IDLE_PRIO		(MAX_RT_PRIO + 2)
 | |
| +#define PRIO_LIMIT		((IDLE_PRIO) + 1)
 | |
| +#else
 | |
|  #define MAX_PRIO		(MAX_RT_PRIO + 40)
 | |
| +#define NORMAL_PRIO	(MAX_RT_PRIO - 20)
 | |
| +#endif
 | |
|  #define DEFAULT_PRIO		(MAX_RT_PRIO + 20)
 | |
|  
 | |
|  static inline int rt_prio(int prio)
 | |
| @@ -1734,7 +1754,7 @@ task_sched_runtime(struct task_struct *t
 | |
|  extern unsigned long long thread_group_sched_runtime(struct task_struct *task);
 | |
|  
 | |
|  /* sched_exec is called by processes performing an exec */
 | |
| -#ifdef CONFIG_SMP
 | |
| +#if defined(CONFIG_SMP) && defined(CONFIG_SCHED_CFS)
 | |
|  extern void sched_exec(void);
 | |
|  #else
 | |
|  #define sched_exec()   {}
 | |
| --- a/init/Kconfig
 | |
| +++ b/init/Kconfig
 | |
| @@ -435,9 +435,22 @@ config LOG_BUF_SHIFT
 | |
|  config HAVE_UNSTABLE_SCHED_CLOCK
 | |
|  	bool
 | |
|  
 | |
| +choice
 | |
| +	prompt "Scheduler"
 | |
| +	default SCHED_CFS
 | |
| +
 | |
| +	config SCHED_CFS
 | |
| +		bool "CFS"
 | |
| +
 | |
| +	config SCHED_BFS
 | |
| +		bool "BFS"
 | |
| +
 | |
| +endchoice
 | |
| +
 | |
|  config GROUP_SCHED
 | |
|  	bool "Group CPU scheduler"
 | |
|  	depends on EXPERIMENTAL
 | |
| +	depends on SCHED_CFS
 | |
|  	default n
 | |
|  	help
 | |
|  	  This feature lets CPU scheduler recognize task groups and control CPU
 | |
| @@ -488,6 +501,7 @@ endchoice
 | |
|  
 | |
|  menuconfig CGROUPS
 | |
|  	boolean "Control Group support"
 | |
| +	depends on SCHED_CFS
 | |
|  	help
 | |
|  	  This option adds support for grouping sets of processes together, for
 | |
|  	  use with process control subsystems such as Cpusets, CFS, memory
 | |
| --- a/kernel/Makefile
 | |
| +++ b/kernel/Makefile
 | |
| @@ -2,7 +2,7 @@
 | |
|  # Makefile for the linux kernel.
 | |
|  #
 | |
|  
 | |
| -obj-y     = sched.o fork.o exec_domain.o panic.o printk.o \
 | |
| +obj-y     = $(if $(CONFIG_SCHED_CFS),sched.o,sched_bfs.o) fork.o exec_domain.o panic.o printk.o \
 | |
|  	    cpu.o exit.o itimer.o time.o softirq.o resource.o \
 | |
|  	    sysctl.o capability.o ptrace.o timer.o user.o \
 | |
|  	    signal.o sys.o kmod.o workqueue.o pid.o \
 | |
| @@ -103,6 +103,7 @@ ifneq ($(CONFIG_SCHED_OMIT_FRAME_POINTER
 | |
|  # I turn this off for IA-64 only.  Andreas Schwab says it's also needed on m68k
 | |
|  # to get a correct value for the wait-channel (WCHAN in ps). --davidm
 | |
|  CFLAGS_sched.o := $(PROFILING) -fno-omit-frame-pointer
 | |
| +CFLAGS_sched_bfs.o := $(PROFILING) -fno-omit-frame-pointer
 | |
|  endif
 | |
|  
 | |
|  $(obj)/configs.o: $(obj)/config_data.h
 | |
| --- a/kernel/kthread.c
 | |
| +++ b/kernel/kthread.c
 | |
| @@ -15,7 +15,11 @@
 | |
|  #include <linux/mutex.h>
 | |
|  #include <trace/sched.h>
 | |
|  
 | |
| +#ifdef CONFIG_SCHED_BFS
 | |
| +#define KTHREAD_NICE_LEVEL (0)
 | |
| +#else
 | |
|  #define KTHREAD_NICE_LEVEL (-5)
 | |
| +#endif
 | |
|  
 | |
|  static DEFINE_SPINLOCK(kthread_create_lock);
 | |
|  static LIST_HEAD(kthread_create_list);
 | |
| --- /dev/null
 | |
| +++ b/kernel/sched_bfs.c
 | |
| @@ -0,0 +1,6059 @@
 | |
| +/*
 | |
| + *  kernel/sched_bfs.c, was sched.c
 | |
| + *
 | |
| + *  Kernel scheduler and related syscalls
 | |
| + *
 | |
| + *  Copyright (C) 1991-2002  Linus Torvalds
 | |
| + *
 | |
| + *  1996-12-23  Modified by Dave Grothe to fix bugs in semaphores and
 | |
| + *		make semaphores SMP safe
 | |
| + *  1998-11-19	Implemented schedule_timeout() and related stuff
 | |
| + *		by Andrea Arcangeli
 | |
| + *  2002-01-04	New ultra-scalable O(1) scheduler by Ingo Molnar:
 | |
| + *		hybrid priority-list and round-robin design with
 | |
| + *		an array-switch method of distributing timeslices
 | |
| + *		and per-CPU runqueues.  Cleanups and useful suggestions
 | |
| + *		by Davide Libenzi, preemptible kernel bits by Robert Love.
 | |
| + *  2003-09-03	Interactivity tuning by Con Kolivas.
 | |
| + *  2004-04-02	Scheduler domains code by Nick Piggin
 | |
| + *  2007-04-15  Work begun on replacing all interactivity tuning with a
 | |
| + *              fair scheduling design by Con Kolivas.
 | |
| + *  2007-05-05  Load balancing (smp-nice) and other improvements
 | |
| + *              by Peter Williams
 | |
| + *  2007-05-06  Interactivity improvements to CFS by Mike Galbraith
 | |
| + *  2007-07-01  Group scheduling enhancements by Srivatsa Vaddagiri
 | |
| + *  2007-11-29  RT balancing improvements by Steven Rostedt, Gregory Haskins,
 | |
| + *              Thomas Gleixner, Mike Kravetz
 | |
| + *  now		Brainfuck deadline scheduling policy by Con Kolivas deletes
 | |
| + *              a whole lot of those previous things.
 | |
| + */
 | |
| +
 | |
| +#include <linux/mm.h>
 | |
| +#include <linux/module.h>
 | |
| +#include <linux/nmi.h>
 | |
| +#include <linux/init.h>
 | |
| +#include <asm/uaccess.h>
 | |
| +#include <linux/highmem.h>
 | |
| +#include <linux/smp_lock.h>
 | |
| +#include <asm/mmu_context.h>
 | |
| +#include <linux/interrupt.h>
 | |
| +#include <linux/capability.h>
 | |
| +#include <linux/completion.h>
 | |
| +#include <linux/kernel_stat.h>
 | |
| +#include <linux/debug_locks.h>
 | |
| +#include <linux/perf_counter.h>
 | |
| +#include <linux/security.h>
 | |
| +#include <linux/notifier.h>
 | |
| +#include <linux/profile.h>
 | |
| +#include <linux/freezer.h>
 | |
| +#include <linux/vmalloc.h>
 | |
| +#include <linux/blkdev.h>
 | |
| +#include <linux/delay.h>
 | |
| +#include <linux/smp.h>
 | |
| +#include <linux/threads.h>
 | |
| +#include <linux/timer.h>
 | |
| +#include <linux/rcupdate.h>
 | |
| +#include <linux/cpu.h>
 | |
| +#include <linux/cpuset.h>
 | |
| +#include <linux/cpumask.h>
 | |
| +#include <linux/percpu.h>
 | |
| +#include <linux/kthread.h>
 | |
| +#include <linux/proc_fs.h>
 | |
| +#include <linux/seq_file.h>
 | |
| +#include <linux/syscalls.h>
 | |
| +#include <linux/times.h>
 | |
| +#include <linux/tsacct_kern.h>
 | |
| +#include <linux/kprobes.h>
 | |
| +#include <linux/delayacct.h>
 | |
| +#include <linux/reciprocal_div.h>
 | |
| +#include <linux/log2.h>
 | |
| +#include <linux/bootmem.h>
 | |
| +#include <linux/ftrace.h>
 | |
| +
 | |
| +#include <asm/tlb.h>
 | |
| +#include <asm/unistd.h>
 | |
| +
 | |
| +#define CREATE_TRACE_POINTS
 | |
| +#include <trace/events/sched.h>
 | |
| +
 | |
| +#define rt_prio(prio)		unlikely((prio) < MAX_RT_PRIO)
 | |
| +#define rt_task(p)		rt_prio((p)->prio)
 | |
| +#define rt_queue(rq)		rt_prio((rq)->rq_prio)
 | |
| +#define batch_task(p)		(unlikely((p)->policy == SCHED_BATCH))
 | |
| +#define is_rt_policy(policy)	((policy) == SCHED_FIFO || \
 | |
| +					(policy) == SCHED_RR)
 | |
| +#define has_rt_policy(p)	unlikely(is_rt_policy((p)->policy))
 | |
| +#define idleprio_task(p)	unlikely((p)->policy == SCHED_IDLE)
 | |
| +#define iso_task(p)		unlikely((p)->policy == SCHED_ISO)
 | |
| +#define iso_queue(rq)		unlikely((rq)->rq_policy == SCHED_ISO)
 | |
| +#define ISO_PERIOD		((5 * HZ * num_online_cpus()) + 1)
 | |
| +
 | |
| +/*
 | |
| + * Convert user-nice values [ -20 ... 0 ... 19 ]
 | |
| + * to static priority [ MAX_RT_PRIO..MAX_PRIO-1 ],
 | |
| + * and back.
 | |
| + */
 | |
| +#define NICE_TO_PRIO(nice)	(MAX_RT_PRIO + (nice) + 20)
 | |
| +#define PRIO_TO_NICE(prio)	((prio) - MAX_RT_PRIO - 20)
 | |
| +#define TASK_NICE(p)		PRIO_TO_NICE((p)->static_prio)
 | |
| +
 | |
| +/*
 | |
| + * 'User priority' is the nice value converted to something we
 | |
| + * can work with better when scaling various scheduler parameters,
 | |
| + * it's a [ 0 ... 39 ] range.
 | |
| + */
 | |
| +#define USER_PRIO(p)		((p)-MAX_RT_PRIO)
 | |
| +#define TASK_USER_PRIO(p)	USER_PRIO((p)->static_prio)
 | |
| +#define MAX_USER_PRIO		(USER_PRIO(MAX_PRIO))
 | |
| +#define SCHED_PRIO(p)		((p)+MAX_RT_PRIO)
 | |
| +
 | |
| +/* Some helpers for converting to/from various scales.*/
 | |
| +#define JIFFIES_TO_NS(TIME)	((TIME) * (1000000000 / HZ))
 | |
| +#define MS_TO_NS(TIME)		((TIME) * 1000000)
 | |
| +#define MS_TO_US(TIME)		((TIME) * 1000)
 | |
| +
 | |
| +#ifdef CONFIG_SMP
 | |
| +/*
 | |
| + * Divide a load by a sched group cpu_power : (load / sg->__cpu_power)
 | |
| + * Since cpu_power is a 'constant', we can use a reciprocal divide.
 | |
| + */
 | |
| +static inline u32 sg_div_cpu_power(const struct sched_group *sg, u32 load)
 | |
| +{
 | |
| +	return reciprocal_divide(load, sg->reciprocal_cpu_power);
 | |
| +}
 | |
| +
 | |
| +/*
 | |
| + * Each time a sched group cpu_power is changed,
 | |
| + * we must compute its reciprocal value
 | |
| + */
 | |
| +static inline void sg_inc_cpu_power(struct sched_group *sg, u32 val)
 | |
| +{
 | |
| +	sg->__cpu_power += val;
 | |
| +	sg->reciprocal_cpu_power = reciprocal_value(sg->__cpu_power);
 | |
| +}
 | |
| +#endif
 | |
| +
 | |
| +/*
 | |
| + * This is the time all tasks within the same priority round robin.
 | |
| + * Value is in ms and set to a minimum of 6ms. Scales with number of cpus.
 | |
| + * Tunable via /proc interface.
 | |
| + */
 | |
| +int rr_interval __read_mostly = 6;
 | |
| +
 | |
| +/*
 | |
| + * sched_iso_cpu - sysctl which determines the cpu percentage SCHED_ISO tasks
 | |
| + * are allowed to run five seconds as real time tasks. This is the total over
 | |
| + * all online cpus.
 | |
| + */
 | |
| +int sched_iso_cpu __read_mostly = 70;
 | |
| +
 | |
| +int prio_ratios[PRIO_RANGE] __read_mostly;
 | |
| +
 | |
| +static inline unsigned long timeslice(void)
 | |
| +{
 | |
| +	return MS_TO_US(rr_interval);
 | |
| +}
 | |
| +
 | |
| +struct global_rq {
 | |
| +	spinlock_t lock;
 | |
| +	unsigned long nr_running;
 | |
| +	unsigned long nr_uninterruptible;
 | |
| +	unsigned long long nr_switches;
 | |
| +	struct list_head queue[PRIO_LIMIT];
 | |
| +	DECLARE_BITMAP(prio_bitmap, PRIO_LIMIT + 1);
 | |
| +	unsigned long iso_ticks;
 | |
| +	unsigned short iso_refractory;
 | |
| +#ifdef CONFIG_SMP
 | |
| +	unsigned long qnr; /* queued not running */
 | |
| +	cpumask_t cpu_idle_map;
 | |
| +#endif
 | |
| +};
 | |
| +
 | |
| +static struct global_rq grq;
 | |
| +
 | |
| +/*
 | |
| + * This is the main, per-CPU runqueue data structure.
 | |
| + * All this is protected by the global_rq lock.
 | |
| + */
 | |
| +struct rq {
 | |
| +#ifdef CONFIG_SMP
 | |
| +#ifdef CONFIG_NO_HZ
 | |
| +	unsigned char in_nohz_recently;
 | |
| +#endif
 | |
| +#endif
 | |
| +
 | |
| +	struct task_struct *curr, *idle;
 | |
| +	struct mm_struct *prev_mm;
 | |
| +	struct list_head queue; /* Place to store currently running task */
 | |
| +
 | |
| +	/* Stored data about rq->curr to work outside grq lock */
 | |
| +	unsigned long rq_deadline;
 | |
| +	unsigned int rq_policy;
 | |
| +	int rq_time_slice;
 | |
| +	int rq_prio;
 | |
| +
 | |
| +	/* Accurate timekeeping data */
 | |
| +	u64 timekeep_clock;
 | |
| +	unsigned long user_pc, nice_pc, irq_pc, softirq_pc, system_pc,
 | |
| +			iowait_pc, idle_pc;
 | |
| +	atomic_t nr_iowait;
 | |
| +
 | |
| +	int cpu;		/* cpu of this runqueue */
 | |
| +	int online;
 | |
| +
 | |
| +#ifdef CONFIG_SMP
 | |
| +	struct root_domain *rd;
 | |
| +	struct sched_domain *sd;
 | |
| +
 | |
| +	struct list_head migration_queue;
 | |
| +#endif
 | |
| +
 | |
| +	u64 clock;
 | |
| +#ifdef CONFIG_SCHEDSTATS
 | |
| +
 | |
| +	/* latency stats */
 | |
| +	struct sched_info rq_sched_info;
 | |
| +	unsigned long long rq_cpu_time;
 | |
| +	/* could above be rq->cfs_rq.exec_clock + rq->rt_rq.rt_runtime ? */
 | |
| +
 | |
| +	/* sys_sched_yield() stats */
 | |
| +	unsigned int yld_count;
 | |
| +
 | |
| +	/* schedule() stats */
 | |
| +	unsigned int sched_switch;
 | |
| +	unsigned int sched_count;
 | |
| +	unsigned int sched_goidle;
 | |
| +
 | |
| +	/* try_to_wake_up() stats */
 | |
| +	unsigned int ttwu_count;
 | |
| +	unsigned int ttwu_local;
 | |
| +
 | |
| +	/* BKL stats */
 | |
| +	unsigned int bkl_count;
 | |
| +#endif
 | |
| +};
 | |
| +
 | |
| +static DEFINE_PER_CPU(struct rq, runqueues) ____cacheline_aligned_in_smp;
 | |
| +static DEFINE_MUTEX(sched_hotcpu_mutex);
 | |
| +
 | |
| +#ifdef CONFIG_SMP
 | |
| +
 | |
| +/*
 | |
| + * We add the notion of a root-domain which will be used to define per-domain
 | |
| + * variables. Each exclusive cpuset essentially defines an island domain by
 | |
| + * fully partitioning the member cpus from any other cpuset. Whenever a new
 | |
| + * exclusive cpuset is created, we also create and attach a new root-domain
 | |
| + * object.
 | |
| + *
 | |
| + */
 | |
| +struct root_domain {
 | |
| +	atomic_t refcount;
 | |
| +	cpumask_var_t span;
 | |
| +	cpumask_var_t online;
 | |
| +
 | |
| +	/*
 | |
| +	 * The "RT overload" flag: it gets set if a CPU has more than
 | |
| +	 * one runnable RT task.
 | |
| +	 */
 | |
| +	cpumask_var_t rto_mask;
 | |
| +	atomic_t rto_count;
 | |
| +#if defined(CONFIG_SCHED_MC) || defined(CONFIG_SCHED_SMT)
 | |
| +	/*
 | |
| +	 * Preferred wake up cpu nominated by sched_mc balance that will be
 | |
| +	 * used when most cpus are idle in the system indicating overall very
 | |
| +	 * low system utilisation. Triggered at POWERSAVINGS_BALANCE_WAKEUP(2)
 | |
| +	 */
 | |
| +	unsigned int sched_mc_preferred_wakeup_cpu;
 | |
| +#endif
 | |
| +};
 | |
| +
 | |
| +/*
 | |
| + * By default the system creates a single root-domain with all cpus as
 | |
| + * members (mimicking the global state we have today).
 | |
| + */
 | |
| +static struct root_domain def_root_domain;
 | |
| +
 | |
| +#endif
 | |
| +
 | |
| +static inline int cpu_of(struct rq *rq)
 | |
| +{
 | |
| +#ifdef CONFIG_SMP
 | |
| +	return rq->cpu;
 | |
| +#else
 | |
| +	return 0;
 | |
| +#endif
 | |
| +}
 | |
| +
 | |
| +/*
 | |
| + * The domain tree (rq->sd) is protected by RCU's quiescent state transition.
 | |
| + * See detach_destroy_domains: synchronize_sched for details.
 | |
| + *
 | |
| + * The domain tree of any CPU may only be accessed from within
 | |
| + * preempt-disabled sections.
 | |
| + */
 | |
| +#define for_each_domain(cpu, __sd) \
 | |
| +	for (__sd = rcu_dereference(cpu_rq(cpu)->sd); __sd; __sd = __sd->parent)
 | |
| +
 | |
| +#define cpu_rq(cpu)		(&per_cpu(runqueues, (cpu)))
 | |
| +#define this_rq()		(&__get_cpu_var(runqueues))
 | |
| +#define task_rq(p)		cpu_rq(task_cpu(p))
 | |
| +#define cpu_curr(cpu)		(cpu_rq(cpu)->curr)
 | |
| +
 | |
| +#include "sched_stats.h"
 | |
| +
 | |
| +#ifndef prepare_arch_switch
 | |
| +# define prepare_arch_switch(next)	do { } while (0)
 | |
| +#endif
 | |
| +#ifndef finish_arch_switch
 | |
| +# define finish_arch_switch(prev)	do { } while (0)
 | |
| +#endif
 | |
| +
 | |
| +inline void update_rq_clock(struct rq *rq)
 | |
| +{
 | |
| +	rq->clock = sched_clock_cpu(cpu_of(rq));
 | |
| +}
 | |
| +
 | |
| +static inline int task_running(struct task_struct *p)
 | |
| +{
 | |
| +	return (!!p->oncpu);
 | |
| +}
 | |
| +
 | |
| +static inline void grq_lock(void)
 | |
| +	__acquires(grq.lock)
 | |
| +{
 | |
| +	smp_mb();
 | |
| +	spin_lock(&grq.lock);
 | |
| +}
 | |
| +
 | |
| +static inline void grq_unlock(void)
 | |
| +	__releases(grq.lock)
 | |
| +{
 | |
| +	spin_unlock(&grq.lock);
 | |
| +}
 | |
| +
 | |
| +static inline void grq_lock_irq(void)
 | |
| +	__acquires(grq.lock)
 | |
| +{
 | |
| +	smp_mb();
 | |
| +	spin_lock_irq(&grq.lock);
 | |
| +}
 | |
| +
 | |
| +static inline void time_lock_grq(struct rq *rq)
 | |
| +	__acquires(grq.lock)
 | |
| +{
 | |
| +	grq_lock();
 | |
| +	update_rq_clock(rq);
 | |
| +}
 | |
| +
 | |
| +static inline void grq_unlock_irq(void)
 | |
| +	__releases(grq.lock)
 | |
| +{
 | |
| +	spin_unlock_irq(&grq.lock);
 | |
| +}
 | |
| +
 | |
| +static inline void grq_lock_irqsave(unsigned long *flags)
 | |
| +	__acquires(grq.lock)
 | |
| +{
 | |
| +	smp_mb();
 | |
| +	spin_lock_irqsave(&grq.lock, *flags);
 | |
| +}
 | |
| +
 | |
| +static inline void grq_unlock_irqrestore(unsigned long *flags)
 | |
| +	__releases(grq.lock)
 | |
| +{
 | |
| +	spin_unlock_irqrestore(&grq.lock, *flags);
 | |
| +}
 | |
| +
 | |
| +static inline struct rq
 | |
| +*task_grq_lock(struct task_struct *p, unsigned long *flags)
 | |
| +	__acquires(grq.lock)
 | |
| +{
 | |
| +	grq_lock_irqsave(flags);
 | |
| +	return task_rq(p);
 | |
| +}
 | |
| +
 | |
| +static inline struct rq
 | |
| +*time_task_grq_lock(struct task_struct *p, unsigned long *flags)
 | |
| +	__acquires(grq.lock)
 | |
| +{
 | |
| +	struct rq *rq = task_grq_lock(p, flags);
 | |
| +	update_rq_clock(rq);
 | |
| +	return rq;
 | |
| +}
 | |
| +
 | |
| +static inline void task_grq_unlock(unsigned long *flags)
 | |
| +	__releases(grq.lock)
 | |
| +{
 | |
| +	grq_unlock_irqrestore(flags);
 | |
| +}
 | |
| +
 | |
| +/**
 | |
| + * runqueue_is_locked
 | |
| + *
 | |
| + * Returns true if the global runqueue is locked.
 | |
| + * This interface allows printk to be called with the runqueue lock
 | |
| + * held and know whether or not it is OK to wake up the klogd.
 | |
| + */
 | |
| +int runqueue_is_locked(void)
 | |
| +{
 | |
| +	return spin_is_locked(&grq.lock);
 | |
| +}
 | |
| +
 | |
| +void task_rq_unlock_wait(struct task_struct *p)
 | |
| +	__releases(grq.lock)
 | |
| +{
 | |
| +	smp_mb(); /* spin-unlock-wait is not a full memory barrier */
 | |
| +	spin_unlock_wait(&grq.lock);
 | |
| +}
 | |
| +
 | |
| +static inline void time_grq_lock(struct rq *rq, unsigned long *flags)
 | |
| +	__acquires(grq.lock)
 | |
| +{
 | |
| +	spin_lock_irqsave(&grq.lock, *flags);
 | |
| +	update_rq_clock(rq);
 | |
| +}
 | |
| +
 | |
| +static inline struct rq *__task_grq_lock(struct task_struct *p)
 | |
| +	__acquires(grq.lock)
 | |
| +{
 | |
| +	grq_lock();
 | |
| +	return task_rq(p);
 | |
| +}
 | |
| +
 | |
| +static inline void __task_grq_unlock(void)
 | |
| +	__releases(grq.lock)
 | |
| +{
 | |
| +	grq_unlock();
 | |
| +}
 | |
| +
 | |
| +#ifndef __ARCH_WANT_UNLOCKED_CTXSW
 | |
| +static inline void prepare_lock_switch(struct rq *rq, struct task_struct *next)
 | |
| +{
 | |
| +}
 | |
| +
 | |
| +static inline void finish_lock_switch(struct rq *rq, struct task_struct *prev)
 | |
| +{
 | |
| +#ifdef CONFIG_DEBUG_SPINLOCK
 | |
| +	/* this is a valid case when another task releases the spinlock */
 | |
| +	grq.lock.owner = current;
 | |
| +#endif
 | |
| +	/*
 | |
| +	 * If we are tracking spinlock dependencies then we have to
 | |
| +	 * fix up the runqueue lock - which gets 'carried over' from
 | |
| +	 * prev into current:
 | |
| +	 */
 | |
| +	spin_acquire(&grq.lock.dep_map, 0, 0, _THIS_IP_);
 | |
| +
 | |
| +	grq_unlock_irq();
 | |
| +}
 | |
| +
 | |
| +#else /* __ARCH_WANT_UNLOCKED_CTXSW */
 | |
| +
 | |
| +static inline void prepare_lock_switch(struct rq *rq, struct task_struct *next)
 | |
| +{
 | |
| +#ifdef __ARCH_WANT_INTERRUPTS_ON_CTXSW
 | |
| +	grq_unlock_irq();
 | |
| +#else
 | |
| +	grq_unlock();
 | |
| +#endif
 | |
| +}
 | |
| +
 | |
| +static inline void finish_lock_switch(struct rq *rq, struct task_struct *prev)
 | |
| +{
 | |
| +	smp_wmb();
 | |
| +#ifndef __ARCH_WANT_INTERRUPTS_ON_CTXSW
 | |
| +	local_irq_enable();
 | |
| +#endif
 | |
| +}
 | |
| +#endif /* __ARCH_WANT_UNLOCKED_CTXSW */
 | |
| +
 | |
| +/*
 | |
| + * A task that is queued will be on the grq run list.
 | |
| + * A task that is not running or queued will not be on the grq run list.
 | |
| + * A task that is currently running will have ->oncpu set and be queued
 | |
| + * temporarily in its own rq queue.
 | |
| + * A task that is running and no longer queued will be seen only on
 | |
| + * context switch exit.
 | |
| + */
 | |
| +
 | |
| +static inline int task_queued(struct task_struct *p)
 | |
| +{
 | |
| +	return (!list_empty(&p->rt.run_list));
 | |
| +}
 | |
| +
 | |
| +static inline int task_queued_only(struct task_struct *p)
 | |
| +{
 | |
| +	return (!list_empty(&p->rt.run_list) && !task_running(p));
 | |
| +}
 | |
| +
 | |
| +/*
 | |
| + * Removing from the global runqueue. Enter with grq locked.
 | |
| + */
 | |
| +static void dequeue_task(struct task_struct *p)
 | |
| +{
 | |
| +	list_del_init(&p->rt.run_list);
 | |
| +	if (list_empty(grq.queue + p->prio))
 | |
| +		__clear_bit(p->prio, grq.prio_bitmap);
 | |
| +}
 | |
| +
 | |
| +static inline void reset_first_time_slice(struct task_struct *p)
 | |
| +{
 | |
| +	if (unlikely(p->first_time_slice))
 | |
| +		p->first_time_slice = 0;
 | |
| +}
 | |
| +
 | |
| +static int idleprio_suitable(struct task_struct *p)
 | |
| +{
 | |
| +	return (!freezing(p) && !signal_pending(p) &&
 | |
| +		!(task_contributes_to_load(p)) && !(p->flags & (PF_EXITING)));
 | |
| +}
 | |
| +
 | |
| +static int isoprio_suitable(void)
 | |
| +{
 | |
| +	return !grq.iso_refractory;
 | |
| +}
 | |
| +
 | |
| +/*
 | |
| + * Adding to the global runqueue. Enter with grq locked.
 | |
| + */
 | |
| +static void enqueue_task(struct task_struct *p)
 | |
| +{
 | |
| +	if (!rt_task(p)) {
 | |
| +		/* Check it hasn't gotten rt from PI */
 | |
| +		if ((idleprio_task(p) && idleprio_suitable(p)) ||
 | |
| +		   (iso_task(p) && isoprio_suitable()))
 | |
| +			p->prio = p->normal_prio;
 | |
| +		else
 | |
| +			p->prio = NORMAL_PRIO;
 | |
| +	}
 | |
| +	__set_bit(p->prio, grq.prio_bitmap);
 | |
| +	list_add_tail(&p->rt.run_list, grq.queue + p->prio);
 | |
| +	sched_info_queued(p);
 | |
| +}
 | |
| +
 | |
| +/* Only idle task does this as a real time task*/
 | |
| +static inline void enqueue_task_head(struct task_struct *p)
 | |
| +{
 | |
| +	__set_bit(p->prio, grq.prio_bitmap);
 | |
| +	list_add(&p->rt.run_list, grq.queue + p->prio);
 | |
| +	sched_info_queued(p);
 | |
| +}
 | |
| +
 | |
| +static inline void requeue_task(struct task_struct *p)
 | |
| +{
 | |
| +	sched_info_queued(p);
 | |
| +}
 | |
| +
 | |
| +static inline int pratio(struct task_struct *p)
 | |
| +{
 | |
| +	return prio_ratios[TASK_USER_PRIO(p)];
 | |
| +}
 | |
| +
 | |
| +/*
 | |
| + * task_timeslice - all tasks of all priorities get the exact same timeslice
 | |
| + * length. CPU distribution is handled by giving different deadlines to
 | |
| + * tasks of different priorities.
 | |
| + */
 | |
| +static inline int task_timeslice(struct task_struct *p)
 | |
| +{
 | |
| +	return (rr_interval * pratio(p) / 100);
 | |
| +}
 | |
| +
 | |
| +#ifdef CONFIG_SMP
 | |
| +static inline void inc_qnr(void)
 | |
| +{
 | |
| +	grq.qnr++;
 | |
| +}
 | |
| +
 | |
| +static inline void dec_qnr(void)
 | |
| +{
 | |
| +	grq.qnr--;
 | |
| +}
 | |
| +
 | |
| +static inline int queued_notrunning(void)
 | |
| +{
 | |
| +	return grq.qnr;
 | |
| +}
 | |
| +#else
 | |
| +static inline void inc_qnr(void)
 | |
| +{
 | |
| +}
 | |
| +
 | |
| +static inline void dec_qnr(void)
 | |
| +{
 | |
| +}
 | |
| +
 | |
| +static inline int queued_notrunning(void)
 | |
| +{
 | |
| +	return grq.nr_running;
 | |
| +}
 | |
| +#endif
 | |
| +
 | |
| +/*
 | |
| + * activate_idle_task - move idle task to the _front_ of runqueue.
 | |
| + */
 | |
| +static inline void activate_idle_task(struct task_struct *p)
 | |
| +{
 | |
| +	enqueue_task_head(p);
 | |
| +	grq.nr_running++;
 | |
| +	inc_qnr();
 | |
| +}
 | |
| +
 | |
| +static inline int normal_prio(struct task_struct *p)
 | |
| +{
 | |
| +	if (has_rt_policy(p))
 | |
| +		return MAX_RT_PRIO - 1 - p->rt_priority;
 | |
| +	if (idleprio_task(p))
 | |
| +		return IDLE_PRIO;
 | |
| +	if (iso_task(p))
 | |
| +		return ISO_PRIO;
 | |
| +	return NORMAL_PRIO;
 | |
| +}
 | |
| +
 | |
| +/*
 | |
| + * Calculate the current priority, i.e. the priority
 | |
| + * taken into account by the scheduler. This value might
 | |
| + * be boosted by RT tasks as it will be RT if the task got
 | |
| + * RT-boosted. If not then it returns p->normal_prio.
 | |
| + */
 | |
| +static int effective_prio(struct task_struct *p)
 | |
| +{
 | |
| +	p->normal_prio = normal_prio(p);
 | |
| +	/*
 | |
| +	 * If we are RT tasks or we were boosted to RT priority,
 | |
| +	 * keep the priority unchanged. Otherwise, update priority
 | |
| +	 * to the normal priority:
 | |
| +	 */
 | |
| +	if (!rt_prio(p->prio))
 | |
| +		return p->normal_prio;
 | |
| +	return p->prio;
 | |
| +}
 | |
| +
 | |
| +/*
 | |
| + * activate_task - move a task to the runqueue. Enter with grq locked. The rq
 | |
| + * doesn't really matter but gives us the local clock.
 | |
| + */
 | |
| +static void activate_task(struct task_struct *p, struct rq *rq)
 | |
| +{
 | |
| +	u64 now = rq->clock;
 | |
| +
 | |
| +	/*
 | |
| +	 * Sleep time is in units of nanosecs, so shift by 20 to get a
 | |
| +	 * milliseconds-range estimation of the amount of time that the task
 | |
| +	 * spent sleeping:
 | |
| +	 */
 | |
| +	if (unlikely(prof_on == SLEEP_PROFILING)) {
 | |
| +		if (p->state == TASK_UNINTERRUPTIBLE)
 | |
| +			profile_hits(SLEEP_PROFILING, (void *)get_wchan(p),
 | |
| +				     (now - p->timestamp) >> 20);
 | |
| +	}
 | |
| +
 | |
| +	p->prio = effective_prio(p);
 | |
| +	p->timestamp = now;
 | |
| +	if (task_contributes_to_load(p))
 | |
| +		grq.nr_uninterruptible--;
 | |
| +	enqueue_task(p);
 | |
| +	grq.nr_running++;
 | |
| +	inc_qnr();
 | |
| +}
 | |
| +
 | |
| +/*
 | |
| + * deactivate_task - If it's running, it's not on the grq and we can just
 | |
| + * decrement the nr_running.
 | |
| + */
 | |
| +static inline void deactivate_task(struct task_struct *p)
 | |
| +{
 | |
| +	if (task_contributes_to_load(p))
 | |
| +		grq.nr_uninterruptible++;
 | |
| +	grq.nr_running--;
 | |
| +}
 | |
| +
 | |
| +#ifdef CONFIG_SMP
 | |
| +void set_task_cpu(struct task_struct *p, unsigned int cpu)
 | |
| +{
 | |
| +	trace_sched_migrate_task(p, cpu);
 | |
| +	/*
 | |
| +	 * After ->cpu is set up to a new value, task_grq_lock(p, ...) can be
 | |
| +	 * successfuly executed on another CPU. We must ensure that updates of
 | |
| +	 * per-task data have been completed by this moment.
 | |
| +	 */
 | |
| +	smp_wmb();
 | |
| +	task_thread_info(p)->cpu = cpu;
 | |
| +}
 | |
| +#endif
 | |
| +
 | |
| +/*
 | |
| + * Move a task off the global queue and take it to a cpu for it will
 | |
| + * become the running task.
 | |
| + */
 | |
| +static inline void take_task(struct rq *rq, struct task_struct *p)
 | |
| +{
 | |
| +	set_task_cpu(p, rq->cpu);
 | |
| +	dequeue_task(p);
 | |
| +	list_add(&p->rt.run_list, &rq->queue);
 | |
| +	dec_qnr();
 | |
| +}
 | |
| +
 | |
| +/*
 | |
| + * Returns a descheduling task to the grq runqueue unless it is being
 | |
| + * deactivated.
 | |
| + */
 | |
| +static inline void return_task(struct task_struct *p, int deactivate)
 | |
| +{
 | |
| +	list_del_init(&p->rt.run_list);
 | |
| +	if (deactivate)
 | |
| +		deactivate_task(p);
 | |
| +	else {
 | |
| +		inc_qnr();
 | |
| +		enqueue_task(p);
 | |
| +	}
 | |
| +}
 | |
| +
 | |
| +/*
 | |
| + * resched_task - mark a task 'to be rescheduled now'.
 | |
| + *
 | |
| + * On UP this means the setting of the need_resched flag, on SMP it
 | |
| + * might also involve a cross-CPU call to trigger the scheduler on
 | |
| + * the target CPU.
 | |
| + */
 | |
| +#ifdef CONFIG_SMP
 | |
| +
 | |
| +#ifndef tsk_is_polling
 | |
| +#define tsk_is_polling(t) test_tsk_thread_flag(t, TIF_POLLING_NRFLAG)
 | |
| +#endif
 | |
| +
 | |
| +static void resched_task(struct task_struct *p)
 | |
| +{
 | |
| +	int cpu;
 | |
| +
 | |
| +	assert_spin_locked(&grq.lock);
 | |
| +
 | |
| +	if (unlikely(test_tsk_thread_flag(p, TIF_NEED_RESCHED)))
 | |
| +		return;
 | |
| +
 | |
| +	set_tsk_thread_flag(p, TIF_NEED_RESCHED);
 | |
| +
 | |
| +	cpu = task_cpu(p);
 | |
| +	if (cpu == smp_processor_id())
 | |
| +		return;
 | |
| +
 | |
| +	/* NEED_RESCHED must be visible before we test polling */
 | |
| +	smp_mb();
 | |
| +	if (!tsk_is_polling(p))
 | |
| +		smp_send_reschedule(cpu);
 | |
| +}
 | |
| +
 | |
| +#else
 | |
| +static inline void resched_task(struct task_struct *p)
 | |
| +{
 | |
| +	assert_spin_locked(&grq.lock);
 | |
| +	set_tsk_need_resched(p);
 | |
| +}
 | |
| +#endif
 | |
| +
 | |
| +/**
 | |
| + * task_curr - is this task currently executing on a CPU?
 | |
| + * @p: the task in question.
 | |
| + */
 | |
| +inline int task_curr(const struct task_struct *p)
 | |
| +{
 | |
| +	return cpu_curr(task_cpu(p)) == p;
 | |
| +}
 | |
| +
 | |
| +#ifdef CONFIG_SMP
 | |
| +struct migration_req {
 | |
| +	struct list_head list;
 | |
| +
 | |
| +	struct task_struct *task;
 | |
| +	int dest_cpu;
 | |
| +
 | |
| +	struct completion done;
 | |
| +};
 | |
| +
 | |
| +/*
 | |
| + * wait_task_context_switch -	wait for a thread to complete at least one
 | |
| + *				context switch.
 | |
| + *
 | |
| + * @p must not be current.
 | |
| + */
 | |
| +void wait_task_context_switch(struct task_struct *p)
 | |
| +{
 | |
| +	unsigned long nvcsw, nivcsw, flags;
 | |
| +	int running;
 | |
| +	struct rq *rq;
 | |
| +
 | |
| +	nvcsw	= p->nvcsw;
 | |
| +	nivcsw	= p->nivcsw;
 | |
| +	for (;;) {
 | |
| +		/*
 | |
| +		 * The runqueue is assigned before the actual context
 | |
| +		 * switch. We need to take the runqueue lock.
 | |
| +		 *
 | |
| +		 * We could check initially without the lock but it is
 | |
| +		 * very likely that we need to take the lock in every
 | |
| +		 * iteration.
 | |
| +		 */
 | |
| +		rq = task_grq_lock(p, &flags);
 | |
| +		running = task_running(p);
 | |
| +		task_grq_unlock(&flags);
 | |
| +
 | |
| +		if (likely(!running))
 | |
| +			break;
 | |
| +		/*
 | |
| +		 * The switch count is incremented before the actual
 | |
| +		 * context switch. We thus wait for two switches to be
 | |
| +		 * sure at least one completed.
 | |
| +		 */
 | |
| +		if ((p->nvcsw - nvcsw) > 1)
 | |
| +			break;
 | |
| +		if ((p->nivcsw - nivcsw) > 1)
 | |
| +			break;
 | |
| +
 | |
| +		cpu_relax();
 | |
| +	}
 | |
| +}
 | |
| +
 | |
| +/*
 | |
| + * wait_task_inactive - wait for a thread to unschedule.
 | |
| + *
 | |
| + * If @match_state is nonzero, it's the @p->state value just checked and
 | |
| + * not expected to change.  If it changes, i.e. @p might have woken up,
 | |
| + * then return zero.  When we succeed in waiting for @p to be off its CPU,
 | |
| + * we return a positive number (its total switch count).  If a second call
 | |
| + * a short while later returns the same number, the caller can be sure that
 | |
| + * @p has remained unscheduled the whole time.
 | |
| + *
 | |
| + * The caller must ensure that the task *will* unschedule sometime soon,
 | |
| + * else this function might spin for a *long* time. This function can't
 | |
| + * be called with interrupts off, or it may introduce deadlock with
 | |
| + * smp_call_function() if an IPI is sent by the same process we are
 | |
| + * waiting to become inactive.
 | |
| + */
 | |
| +unsigned long wait_task_inactive(struct task_struct *p, long match_state)
 | |
| +{
 | |
| +	unsigned long flags;
 | |
| +	int running, on_rq;
 | |
| +	unsigned long ncsw;
 | |
| +	struct rq *rq;
 | |
| +
 | |
| +	for (;;) {
 | |
| +		/*
 | |
| +		 * We do the initial early heuristics without holding
 | |
| +		 * any task-queue locks at all. We'll only try to get
 | |
| +		 * the runqueue lock when things look like they will
 | |
| +		 * work out!
 | |
| +		 */
 | |
| +		rq = task_rq(p);
 | |
| +
 | |
| +		/*
 | |
| +		 * If the task is actively running on another CPU
 | |
| +		 * still, just relax and busy-wait without holding
 | |
| +		 * any locks.
 | |
| +		 *
 | |
| +		 * NOTE! Since we don't hold any locks, it's not
 | |
| +		 * even sure that "rq" stays as the right runqueue!
 | |
| +		 * But we don't care, since this will
 | |
| +		 * return false if the runqueue has changed and p
 | |
| +		 * is actually now running somewhere else!
 | |
| +		 */
 | |
| +		while (task_running(p) && p == rq->curr) {
 | |
| +			if (match_state && unlikely(p->state != match_state))
 | |
| +				return 0;
 | |
| +			cpu_relax();
 | |
| +		}
 | |
| +
 | |
| +		/*
 | |
| +		 * Ok, time to look more closely! We need the grq
 | |
| +		 * lock now, to be *sure*. If we're wrong, we'll
 | |
| +		 * just go back and repeat.
 | |
| +		 */
 | |
| +		rq = task_grq_lock(p, &flags);
 | |
| +		trace_sched_wait_task(rq, p);
 | |
| +		running = task_running(p);
 | |
| +		on_rq = task_queued(p);
 | |
| +		ncsw = 0;
 | |
| +		if (!match_state || p->state == match_state)
 | |
| +			ncsw = p->nvcsw | LONG_MIN; /* sets MSB */
 | |
| +		task_grq_unlock(&flags);
 | |
| +
 | |
| +		/*
 | |
| +		 * If it changed from the expected state, bail out now.
 | |
| +		 */
 | |
| +		if (unlikely(!ncsw))
 | |
| +			break;
 | |
| +
 | |
| +		/*
 | |
| +		 * Was it really running after all now that we
 | |
| +		 * checked with the proper locks actually held?
 | |
| +		 *
 | |
| +		 * Oops. Go back and try again..
 | |
| +		 */
 | |
| +		if (unlikely(running)) {
 | |
| +			cpu_relax();
 | |
| +			continue;
 | |
| +		}
 | |
| +
 | |
| +		/*
 | |
| +		 * It's not enough that it's not actively running,
 | |
| +		 * it must be off the runqueue _entirely_, and not
 | |
| +		 * preempted!
 | |
| +		 *
 | |
| +		 * So if it was still runnable (but just not actively
 | |
| +		 * running right now), it's preempted, and we should
 | |
| +		 * yield - it could be a while.
 | |
| +		 */
 | |
| +		if (unlikely(on_rq)) {
 | |
| +			schedule_timeout_uninterruptible(1);
 | |
| +			continue;
 | |
| +		}
 | |
| +
 | |
| +		/*
 | |
| +		 * Ahh, all good. It wasn't running, and it wasn't
 | |
| +		 * runnable, which means that it will never become
 | |
| +		 * running in the future either. We're all done!
 | |
| +		 */
 | |
| +		break;
 | |
| +	}
 | |
| +
 | |
| +	return ncsw;
 | |
| +}
 | |
| +
 | |
| +/***
 | |
| + * kick_process - kick a running thread to enter/exit the kernel
 | |
| + * @p: the to-be-kicked thread
 | |
| + *
 | |
| + * Cause a process which is running on another CPU to enter
 | |
| + * kernel-mode, without any delay. (to get signals handled.)
 | |
| + *
 | |
| + * NOTE: this function doesnt have to take the runqueue lock,
 | |
| + * because all it wants to ensure is that the remote task enters
 | |
| + * the kernel. If the IPI races and the task has been migrated
 | |
| + * to another CPU then no harm is done and the purpose has been
 | |
| + * achieved as well.
 | |
| + */
 | |
| +void kick_process(struct task_struct *p)
 | |
| +{
 | |
| +	int cpu;
 | |
| +
 | |
| +	preempt_disable();
 | |
| +	cpu = task_cpu(p);
 | |
| +	if ((cpu != smp_processor_id()) && task_curr(p))
 | |
| +		smp_send_reschedule(cpu);
 | |
| +	preempt_enable();
 | |
| +}
 | |
| +EXPORT_SYMBOL_GPL(kick_process);
 | |
| +#endif
 | |
| +
 | |
| +#define rq_idle(rq)	((rq)->rq_prio == PRIO_LIMIT)
 | |
| +
 | |
| +/*
 | |
| + * RT tasks preempt purely on priority. SCHED_NORMAL tasks preempt on the
 | |
| + * basis of earlier deadlines. SCHED_BATCH and SCHED_IDLE don't preempt,
 | |
| + * they cooperatively multitask.
 | |
| + */
 | |
| +static inline int task_preempts_curr(struct task_struct *p, struct rq *rq)
 | |
| +{
 | |
| +	int preempts = 0;
 | |
| +
 | |
| +	if (p->prio < rq->rq_prio)
 | |
| +		preempts = 1;
 | |
| +	else if (p->policy == SCHED_NORMAL && (p->prio == rq->rq_prio &&
 | |
| +		 time_before(p->deadline, rq->rq_deadline)))
 | |
| +			preempts = 1;
 | |
| +	return preempts;
 | |
| +}
 | |
| +
 | |
| +/*
 | |
| + * Wake up *any* suitable cpu to schedule this task.
 | |
| + */
 | |
| +static void try_preempt(struct task_struct *p)
 | |
| +{
 | |
| +	struct rq *highest_prio_rq, *this_rq;
 | |
| +	unsigned long latest_deadline, cpu;
 | |
| +	int highest_prio;
 | |
| +	cpumask_t tmp;
 | |
| +
 | |
| +	/* Try the task's previous rq first and as a fallback */
 | |
| +	this_rq = task_rq(p);
 | |
| +
 | |
| +	if (cpu_isset(this_rq->cpu, p->cpus_allowed)) {
 | |
| +		highest_prio_rq = this_rq;
 | |
| +		/* If this_rq is idle, use that. */
 | |
| +		if (rq_idle(this_rq))
 | |
| +			goto found_rq;
 | |
| +	} else
 | |
| +		highest_prio_rq = cpu_rq(any_online_cpu(p->cpus_allowed));
 | |
| +	latest_deadline = this_rq->rq_deadline;
 | |
| +	highest_prio = this_rq->rq_prio;
 | |
| +
 | |
| +	cpus_and(tmp, cpu_online_map, p->cpus_allowed);
 | |
| +
 | |
| +	for_each_cpu_mask(cpu, tmp) {
 | |
| +		struct rq *rq;
 | |
| +		int rq_prio;
 | |
| +
 | |
| +		rq = cpu_rq(cpu);
 | |
| +
 | |
| +		if (rq_idle(rq)) {
 | |
| +			/* found an idle rq, use that one */
 | |
| +			highest_prio_rq = rq;
 | |
| +			goto found_rq;
 | |
| +		}
 | |
| +
 | |
| +		rq_prio = rq->rq_prio;
 | |
| +		if (rq_prio > highest_prio ||
 | |
| +			(rq_prio == highest_prio &&
 | |
| +			time_after(rq->rq_deadline, latest_deadline))) {
 | |
| +				highest_prio = rq_prio;
 | |
| +				latest_deadline = rq->rq_deadline;
 | |
| +				highest_prio_rq = rq;
 | |
| +		}
 | |
| +	}
 | |
| +
 | |
| +	if (!task_preempts_curr(p, highest_prio_rq))
 | |
| +		return;
 | |
| +found_rq:
 | |
| +	resched_task(highest_prio_rq->curr);
 | |
| +	return;
 | |
| +}
 | |
| +
 | |
| +/**
 | |
| + * task_oncpu_function_call - call a function on the cpu on which a task runs
 | |
| + * @p:		the task to evaluate
 | |
| + * @func:	the function to be called
 | |
| + * @info:	the function call argument
 | |
| + *
 | |
| + * Calls the function @func when the task is currently running. This might
 | |
| + * be on the current CPU, which just calls the function directly
 | |
| + */
 | |
| +void task_oncpu_function_call(struct task_struct *p,
 | |
| +			      void (*func) (void *info), void *info)
 | |
| +{
 | |
| +	int cpu;
 | |
| +
 | |
| +	preempt_disable();
 | |
| +	cpu = task_cpu(p);
 | |
| +	if (task_curr(p))
 | |
| +		smp_call_function_single(cpu, func, info, 1);
 | |
| +	preempt_enable();
 | |
| +}
 | |
| +
 | |
| +#ifdef CONFIG_SMP
 | |
| +static int suitable_idle_cpus(struct task_struct *p)
 | |
| +{
 | |
| +	return (cpus_intersects(p->cpus_allowed, grq.cpu_idle_map));
 | |
| +}
 | |
| +#else
 | |
| +static int suitable_idle_cpus(struct task_struct *p)
 | |
| +{
 | |
| +	return 0;
 | |
| +}
 | |
| +#endif
 | |
| +
 | |
| +/***
 | |
| + * try_to_wake_up - wake up a thread
 | |
| + * @p: the to-be-woken-up thread
 | |
| + * @state: the mask of task states that can be woken
 | |
| + * @sync: do a synchronous wakeup?
 | |
| + *
 | |
| + * Put it on the run-queue if it's not already there. The "current"
 | |
| + * thread is always on the run-queue (except when the actual
 | |
| + * re-schedule is in progress), and as such you're allowed to do
 | |
| + * the simpler "current->state = TASK_RUNNING" to mark yourself
 | |
| + * runnable without the overhead of this.
 | |
| + *
 | |
| + * returns failure only if the task is already active.
 | |
| + */
 | |
| +static int try_to_wake_up(struct task_struct *p, unsigned int state, int sync)
 | |
| +{
 | |
| +	unsigned long flags;
 | |
| +	int success = 0;
 | |
| +	long old_state;
 | |
| +	struct rq *rq;
 | |
| +
 | |
| +	rq = time_task_grq_lock(p, &flags);
 | |
| +	old_state = p->state;
 | |
| +	if (!(old_state & state))
 | |
| +		goto out_unlock;
 | |
| +
 | |
| +	/*
 | |
| +	 * Note this catches tasks that are running and queued, but returns
 | |
| +	 * false during the context switch when they're running and no
 | |
| +	 * longer queued.
 | |
| +	 */
 | |
| +	if (task_queued(p))
 | |
| +		goto out_running;
 | |
| +
 | |
| +	activate_task(p, rq);
 | |
| +	/*
 | |
| +	 * Sync wakeups (i.e. those types of wakeups where the waker
 | |
| +	 * has indicated that it will leave the CPU in short order)
 | |
| +	 * don't trigger a preemption if there are no idle cpus,
 | |
| +	 * instead waiting for current to deschedule.
 | |
| +	 */
 | |
| +	if (!sync || (sync && suitable_idle_cpus(p)))
 | |
| +		try_preempt(p);
 | |
| +	success = 1;
 | |
| +
 | |
| +out_running:
 | |
| +	trace_sched_wakeup(rq, p, success);
 | |
| +	p->state = TASK_RUNNING;
 | |
| +out_unlock:
 | |
| +	task_grq_unlock(&flags);
 | |
| +	return success;
 | |
| +}
 | |
| +
 | |
| +/**
 | |
| + * wake_up_process - Wake up a specific process
 | |
| + * @p: The process to be woken up.
 | |
| + *
 | |
| + * Attempt to wake up the nominated process and move it to the set of runnable
 | |
| + * processes.  Returns 1 if the process was woken up, 0 if it was already
 | |
| + * running.
 | |
| + *
 | |
| + * It may be assumed that this function implies a write memory barrier before
 | |
| + * changing the task state if and only if any tasks are woken up.
 | |
| + */
 | |
| +int wake_up_process(struct task_struct *p)
 | |
| +{
 | |
| +	return try_to_wake_up(p, TASK_ALL, 0);
 | |
| +}
 | |
| +EXPORT_SYMBOL(wake_up_process);
 | |
| +
 | |
| +int wake_up_state(struct task_struct *p, unsigned int state)
 | |
| +{
 | |
| +	return try_to_wake_up(p, state, 0);
 | |
| +}
 | |
| +
 | |
| +/*
 | |
| + * Perform scheduler related setup for a newly forked process p.
 | |
| + * p is forked by current.
 | |
| + */
 | |
| +void sched_fork(struct task_struct *p, int clone_flags)
 | |
| +{
 | |
| +	int cpu = get_cpu();
 | |
| +	struct rq *rq;
 | |
| +
 | |
| +#ifdef CONFIG_PREEMPT_NOTIFIERS
 | |
| +	INIT_HLIST_HEAD(&p->preempt_notifiers);
 | |
| +#endif
 | |
| +	/*
 | |
| +	 * We mark the process as running here, but have not actually
 | |
| +	 * inserted it onto the runqueue yet. This guarantees that
 | |
| +	 * nobody will actually run it, and a signal or other external
 | |
| +	 * event cannot wake it up and insert it on the runqueue either.
 | |
| +	 */
 | |
| +	p->state = TASK_RUNNING;
 | |
| +	set_task_cpu(p, cpu);
 | |
| +
 | |
| +	/* Should be reset in fork.c but done here for ease of bfs patching */
 | |
| +	p->se.sum_exec_runtime = p->stime_pc = p->utime_pc = 0;
 | |
| +
 | |
| +	/*
 | |
| +	 * Make sure we do not leak PI boosting priority to the child:
 | |
| +	 */
 | |
| +	p->prio = current->normal_prio;
 | |
| +
 | |
| +	INIT_LIST_HEAD(&p->rt.run_list);
 | |
| +#if defined(CONFIG_SCHEDSTATS) || defined(CONFIG_TASK_DELAY_ACCT)
 | |
| +	if (unlikely(sched_info_on()))
 | |
| +		memset(&p->sched_info, 0, sizeof(p->sched_info));
 | |
| +#endif
 | |
| +
 | |
| +	p->oncpu = 0;
 | |
| +
 | |
| +#ifdef CONFIG_PREEMPT
 | |
| +	/* Want to start with kernel preemption disabled. */
 | |
| +	task_thread_info(p)->preempt_count = 1;
 | |
| +#endif
 | |
| +	if (unlikely(p->policy == SCHED_FIFO))
 | |
| +		goto out;
 | |
| +	/*
 | |
| +	 * Share the timeslice between parent and child, thus the
 | |
| +	 * total amount of pending timeslices in the system doesn't change,
 | |
| +	 * resulting in more scheduling fairness. If it's negative, it won't
 | |
| +	 * matter since that's the same as being 0. current's time_slice is
 | |
| +	 * actually in rq_time_slice when it's running.
 | |
| +	 */
 | |
| +	local_irq_disable();
 | |
| +	rq = task_rq(current);
 | |
| +	if (likely(rq->rq_time_slice > 0)) {
 | |
| +		rq->rq_time_slice /= 2;
 | |
| +		/*
 | |
| +		 * The remainder of the first timeslice might be recovered by
 | |
| +		 * the parent if the child exits early enough.
 | |
| +		 */
 | |
| +		p->first_time_slice = 1;
 | |
| +	}
 | |
| +	p->rt.time_slice = rq->rq_time_slice;
 | |
| +	local_irq_enable();
 | |
| +out:
 | |
| +	put_cpu();
 | |
| +}
 | |
| +
 | |
| +/*
 | |
| + * wake_up_new_task - wake up a newly created task for the first time.
 | |
| + *
 | |
| + * This function will do some initial scheduler statistics housekeeping
 | |
| + * that must be done for every newly created context, then puts the task
 | |
| + * on the runqueue and wakes it.
 | |
| + */
 | |
| +void wake_up_new_task(struct task_struct *p, unsigned long clone_flags)
 | |
| +{
 | |
| +	struct task_struct *parent;
 | |
| +	unsigned long flags;
 | |
| +	struct rq *rq;
 | |
| +
 | |
| +	rq = time_task_grq_lock(p, &flags); ;
 | |
| +	parent = p->parent;
 | |
| +	BUG_ON(p->state != TASK_RUNNING);
 | |
| +	set_task_cpu(p, task_cpu(parent));
 | |
| +
 | |
| +	activate_task(p, rq);
 | |
| +	trace_sched_wakeup_new(rq, p, 1);
 | |
| +	if (!(clone_flags & CLONE_VM) && rq->curr == parent &&
 | |
| +		!suitable_idle_cpus(p)) {
 | |
| +		/*
 | |
| +		 * The VM isn't cloned, so we're in a good position to
 | |
| +		 * do child-runs-first in anticipation of an exec. This
 | |
| +		 * usually avoids a lot of COW overhead.
 | |
| +		 */
 | |
| +			resched_task(parent);
 | |
| +	} else
 | |
| +		try_preempt(p);
 | |
| +	task_grq_unlock(&flags);
 | |
| +}
 | |
| +
 | |
| +/*
 | |
| + * Potentially available exiting-child timeslices are
 | |
| + * retrieved here - this way the parent does not get
 | |
| + * penalized for creating too many threads.
 | |
| + *
 | |
| + * (this cannot be used to 'generate' timeslices
 | |
| + * artificially, because any timeslice recovered here
 | |
| + * was given away by the parent in the first place.)
 | |
| + */
 | |
| +void sched_exit(struct task_struct *p)
 | |
| +{
 | |
| +	struct task_struct *parent;
 | |
| +	unsigned long flags;
 | |
| +	struct rq *rq;
 | |
| +
 | |
| +	if (p->first_time_slice) {
 | |
| +		parent = p->parent;
 | |
| +		rq = task_grq_lock(parent, &flags);
 | |
| +		parent->rt.time_slice += p->rt.time_slice;
 | |
| +		if (unlikely(parent->rt.time_slice > timeslice()))
 | |
| +			parent->rt.time_slice = timeslice();
 | |
| +		task_grq_unlock(&flags);
 | |
| +	}
 | |
| +}
 | |
| +
 | |
| +#ifdef CONFIG_PREEMPT_NOTIFIERS
 | |
| +
 | |
| +/**
 | |
| + * preempt_notifier_register - tell me when current is being preempted & rescheduled
 | |
| + * @notifier: notifier struct to register
 | |
| + */
 | |
| +void preempt_notifier_register(struct preempt_notifier *notifier)
 | |
| +{
 | |
| +	hlist_add_head(¬ifier->link, ¤t->preempt_notifiers);
 | |
| +}
 | |
| +EXPORT_SYMBOL_GPL(preempt_notifier_register);
 | |
| +
 | |
| +/**
 | |
| + * preempt_notifier_unregister - no longer interested in preemption notifications
 | |
| + * @notifier: notifier struct to unregister
 | |
| + *
 | |
| + * This is safe to call from within a preemption notifier.
 | |
| + */
 | |
| +void preempt_notifier_unregister(struct preempt_notifier *notifier)
 | |
| +{
 | |
| +	hlist_del(¬ifier->link);
 | |
| +}
 | |
| +EXPORT_SYMBOL_GPL(preempt_notifier_unregister);
 | |
| +
 | |
| +static void fire_sched_in_preempt_notifiers(struct task_struct *curr)
 | |
| +{
 | |
| +	struct preempt_notifier *notifier;
 | |
| +	struct hlist_node *node;
 | |
| +
 | |
| +	hlist_for_each_entry(notifier, node, &curr->preempt_notifiers, link)
 | |
| +		notifier->ops->sched_in(notifier, raw_smp_processor_id());
 | |
| +}
 | |
| +
 | |
| +static void
 | |
| +fire_sched_out_preempt_notifiers(struct task_struct *curr,
 | |
| +				 struct task_struct *next)
 | |
| +{
 | |
| +	struct preempt_notifier *notifier;
 | |
| +	struct hlist_node *node;
 | |
| +
 | |
| +	hlist_for_each_entry(notifier, node, &curr->preempt_notifiers, link)
 | |
| +		notifier->ops->sched_out(notifier, next);
 | |
| +}
 | |
| +
 | |
| +#else /* !CONFIG_PREEMPT_NOTIFIERS */
 | |
| +
 | |
| +static void fire_sched_in_preempt_notifiers(struct task_struct *curr)
 | |
| +{
 | |
| +}
 | |
| +
 | |
| +static void
 | |
| +fire_sched_out_preempt_notifiers(struct task_struct *curr,
 | |
| +				 struct task_struct *next)
 | |
| +{
 | |
| +}
 | |
| +
 | |
| +#endif /* CONFIG_PREEMPT_NOTIFIERS */
 | |
| +
 | |
| +/**
 | |
| + * prepare_task_switch - prepare to switch tasks
 | |
| + * @rq: the runqueue preparing to switch
 | |
| + * @next: the task we are going to switch to.
 | |
| + *
 | |
| + * This is called with the rq lock held and interrupts off. It must
 | |
| + * be paired with a subsequent finish_task_switch after the context
 | |
| + * switch.
 | |
| + *
 | |
| + * prepare_task_switch sets up locking and calls architecture specific
 | |
| + * hooks.
 | |
| + */
 | |
| +static inline void
 | |
| +prepare_task_switch(struct rq *rq, struct task_struct *prev,
 | |
| +		    struct task_struct *next)
 | |
| +{
 | |
| +	fire_sched_out_preempt_notifiers(prev, next);
 | |
| +	prepare_lock_switch(rq, next);
 | |
| +	prepare_arch_switch(next);
 | |
| +}
 | |
| +
 | |
| +/**
 | |
| + * finish_task_switch - clean up after a task-switch
 | |
| + * @rq: runqueue associated with task-switch
 | |
| + * @prev: the thread we just switched away from.
 | |
| + *
 | |
| + * finish_task_switch must be called after the context switch, paired
 | |
| + * with a prepare_task_switch call before the context switch.
 | |
| + * finish_task_switch will reconcile locking set up by prepare_task_switch,
 | |
| + * and do any other architecture-specific cleanup actions.
 | |
| + *
 | |
| + * Note that we may have delayed dropping an mm in context_switch(). If
 | |
| + * so, we finish that here outside of the runqueue lock.  (Doing it
 | |
| + * with the lock held can cause deadlocks; see schedule() for
 | |
| + * details.)
 | |
| + */
 | |
| +static inline void finish_task_switch(struct rq *rq, struct task_struct *prev)
 | |
| +	__releases(grq.lock)
 | |
| +{
 | |
| +	struct mm_struct *mm = rq->prev_mm;
 | |
| +	long prev_state;
 | |
| +
 | |
| +	rq->prev_mm = NULL;
 | |
| +
 | |
| +	/*
 | |
| +	 * A task struct has one reference for the use as "current".
 | |
| +	 * If a task dies, then it sets TASK_DEAD in tsk->state and calls
 | |
| +	 * schedule one last time. The schedule call will never return, and
 | |
| +	 * the scheduled task must drop that reference.
 | |
| +	 * The test for TASK_DEAD must occur while the runqueue locks are
 | |
| +	 * still held, otherwise prev could be scheduled on another cpu, die
 | |
| +	 * there before we look at prev->state, and then the reference would
 | |
| +	 * be dropped twice.
 | |
| +	 *		Manfred Spraul <manfred@colorfullife.com>
 | |
| +	 */
 | |
| +	prev_state = prev->state;
 | |
| +	finish_arch_switch(prev);
 | |
| +	perf_counter_task_sched_in(current, cpu_of(rq));
 | |
| +	finish_lock_switch(rq, prev);
 | |
| +
 | |
| +	fire_sched_in_preempt_notifiers(current);
 | |
| +	if (mm)
 | |
| +		mmdrop(mm);
 | |
| +	if (unlikely(prev_state == TASK_DEAD)) {
 | |
| +		/*
 | |
| +		 * Remove function-return probe instances associated with this
 | |
| +		 * task and put them back on the free list.
 | |
| +	 	 */
 | |
| +		kprobe_flush_task(prev);
 | |
| +		put_task_struct(prev);
 | |
| +	}
 | |
| +}
 | |
| +
 | |
| +/**
 | |
| + * schedule_tail - first thing a freshly forked thread must call.
 | |
| + * @prev: the thread we just switched away from.
 | |
| + */
 | |
| +asmlinkage void schedule_tail(struct task_struct *prev)
 | |
| +	__releases(grq.lock)
 | |
| +{
 | |
| +	struct rq *rq = this_rq();
 | |
| +
 | |
| +	finish_task_switch(rq, prev);
 | |
| +#ifdef __ARCH_WANT_UNLOCKED_CTXSW
 | |
| +	/* In this case, finish_task_switch does not reenable preemption */
 | |
| +	preempt_enable();
 | |
| +#endif
 | |
| +	if (current->set_child_tid)
 | |
| +		put_user(current->pid, current->set_child_tid);
 | |
| +}
 | |
| +
 | |
| +/*
 | |
| + * context_switch - switch to the new MM and the new
 | |
| + * thread's register state.
 | |
| + */
 | |
| +static inline void
 | |
| +context_switch(struct rq *rq, struct task_struct *prev,
 | |
| +	       struct task_struct *next)
 | |
| +{
 | |
| +	struct mm_struct *mm, *oldmm;
 | |
| +
 | |
| +	prepare_task_switch(rq, prev, next);
 | |
| +	trace_sched_switch(rq, prev, next);
 | |
| +	mm = next->mm;
 | |
| +	oldmm = prev->active_mm;
 | |
| +	/*
 | |
| +	 * For paravirt, this is coupled with an exit in switch_to to
 | |
| +	 * combine the page table reload and the switch backend into
 | |
| +	 * one hypercall.
 | |
| +	 */
 | |
| +	arch_enter_lazy_cpu_mode();
 | |
| +
 | |
| +	if (unlikely(!mm)) {
 | |
| +		next->active_mm = oldmm;
 | |
| +		atomic_inc(&oldmm->mm_count);
 | |
| +		enter_lazy_tlb(oldmm, next);
 | |
| +	} else
 | |
| +		switch_mm(oldmm, mm, next);
 | |
| +
 | |
| +	if (unlikely(!prev->mm)) {
 | |
| +		prev->active_mm = NULL;
 | |
| +		rq->prev_mm = oldmm;
 | |
| +	}
 | |
| +	/*
 | |
| +	 * Since the runqueue lock will be released by the next
 | |
| +	 * task (which is an invalid locking op but in the case
 | |
| +	 * of the scheduler it's an obvious special-case), so we
 | |
| +	 * do an early lockdep release here:
 | |
| +	 */
 | |
| +#ifndef __ARCH_WANT_UNLOCKED_CTXSW
 | |
| +	spin_release(&grq.lock.dep_map, 1, _THIS_IP_);
 | |
| +#endif
 | |
| +
 | |
| +	/* Here we just switch the register state and the stack. */
 | |
| +	switch_to(prev, next, prev);
 | |
| +
 | |
| +	barrier();
 | |
| +	/*
 | |
| +	 * this_rq must be evaluated again because prev may have moved
 | |
| +	 * CPUs since it called schedule(), thus the 'rq' on its stack
 | |
| +	 * frame will be invalid.
 | |
| +	 */
 | |
| +	finish_task_switch(this_rq(), prev);
 | |
| +}
 | |
| +
 | |
| +/*
 | |
| + * nr_running, nr_uninterruptible and nr_context_switches:
 | |
| + *
 | |
| + * externally visible scheduler statistics: current number of runnable
 | |
| + * threads, current number of uninterruptible-sleeping threads, total
 | |
| + * number of context switches performed since bootup. All are measured
 | |
| + * without grabbing the grq lock but the occasional inaccurate result
 | |
| + * doesn't matter so long as it's positive.
 | |
| + */
 | |
| +unsigned long nr_running(void)
 | |
| +{
 | |
| +	long nr = grq.nr_running;
 | |
| +
 | |
| +	if (unlikely(nr < 0))
 | |
| +		nr = 0;
 | |
| +	return (unsigned long)nr;
 | |
| +}
 | |
| +
 | |
| +unsigned long nr_uninterruptible(void)
 | |
| +{
 | |
| +	unsigned long nu = grq.nr_uninterruptible;
 | |
| +
 | |
| +	if (unlikely(nu < 0))
 | |
| +		nu = 0;
 | |
| +	return nu;
 | |
| +}
 | |
| +
 | |
| +unsigned long long nr_context_switches(void)
 | |
| +{
 | |
| +	long long ns = grq.nr_switches;
 | |
| +
 | |
| +	/* This is of course impossible */
 | |
| +	if (unlikely(ns < 0))
 | |
| +		ns = 1;
 | |
| +	return (long long)ns;
 | |
| +}
 | |
| +
 | |
| +unsigned long nr_iowait(void)
 | |
| +{
 | |
| +	unsigned long i, sum = 0;
 | |
| +
 | |
| +	for_each_possible_cpu(i)
 | |
| +		sum += atomic_read(&cpu_rq(i)->nr_iowait);
 | |
| +
 | |
| +	return sum;
 | |
| +}
 | |
| +
 | |
| +unsigned long nr_active(void)
 | |
| +{
 | |
| +	return nr_running() + nr_uninterruptible();
 | |
| +}
 | |
| +
 | |
| +DEFINE_PER_CPU(struct kernel_stat, kstat);
 | |
| +
 | |
| +EXPORT_PER_CPU_SYMBOL(kstat);
 | |
| +
 | |
| +/*
 | |
| + * On each tick, see what percentage of that tick was attributed to each
 | |
| + * component and add the percentage to the _pc values. Once a _pc value has
 | |
| + * accumulated one tick's worth, account for that. This means the total
 | |
| + * percentage of load components will always be 100 per tick.
 | |
| + */
 | |
| +static void pc_idle_time(struct rq *rq, unsigned long pc)
 | |
| +{
 | |
| +	struct cpu_usage_stat *cpustat = &kstat_this_cpu.cpustat;
 | |
| +	cputime64_t tmp = cputime_to_cputime64(jiffies_to_cputime(1));
 | |
| +
 | |
| +	if (atomic_read(&rq->nr_iowait) > 0) {
 | |
| +		rq->iowait_pc += pc;
 | |
| +		if (rq->iowait_pc >= 100) {
 | |
| +			rq->iowait_pc %= 100;
 | |
| +			cpustat->iowait = cputime64_add(cpustat->iowait, tmp);
 | |
| +		}
 | |
| +	} else {
 | |
| +		rq->idle_pc += pc;
 | |
| +		if (rq->idle_pc >= 100) {
 | |
| +			rq->idle_pc %= 100;
 | |
| +			cpustat->idle = cputime64_add(cpustat->idle, tmp);
 | |
| +		}
 | |
| +	}
 | |
| +}
 | |
| +
 | |
| +static void
 | |
| +pc_system_time(struct rq *rq, struct task_struct *p, int hardirq_offset,
 | |
| +	       unsigned long pc, unsigned long ns)
 | |
| +{
 | |
| +	struct cpu_usage_stat *cpustat = &kstat_this_cpu.cpustat;
 | |
| +	cputime_t one_jiffy = jiffies_to_cputime(1);
 | |
| +	cputime_t one_jiffy_scaled = cputime_to_scaled(one_jiffy);
 | |
| +	cputime64_t tmp = cputime_to_cputime64(one_jiffy);
 | |
| +
 | |
| +	p->stime_pc += pc;
 | |
| +	if (p->stime_pc >= 100) {
 | |
| +		p->stime_pc -= 100;
 | |
| +		p->stime = cputime_add(p->stime, one_jiffy);
 | |
| +		p->stimescaled = cputime_add(p->stimescaled, one_jiffy_scaled);
 | |
| +		account_group_system_time(p, one_jiffy);
 | |
| +		acct_update_integrals(p);
 | |
| +	}
 | |
| +	p->se.sum_exec_runtime += ns;
 | |
| +
 | |
| +	if (hardirq_count() - hardirq_offset)
 | |
| +		rq->irq_pc += pc;
 | |
| +	else if (softirq_count()) {
 | |
| +		rq->softirq_pc += pc;
 | |
| +		if (rq->softirq_pc >= 100) {
 | |
| +			rq->softirq_pc %= 100;
 | |
| +			cpustat->softirq = cputime64_add(cpustat->softirq, tmp);
 | |
| +		}
 | |
| +	} else {
 | |
| +		rq->system_pc += pc;
 | |
| +		if (rq->system_pc >= 100) {
 | |
| +			rq->system_pc %= 100;
 | |
| +			cpustat->system = cputime64_add(cpustat->system, tmp);
 | |
| +		}
 | |
| +	}
 | |
| +}
 | |
| +
 | |
| +static void pc_user_time(struct rq *rq, struct task_struct *p,
 | |
| +			 unsigned long pc, unsigned long ns)
 | |
| +{
 | |
| +	struct cpu_usage_stat *cpustat = &kstat_this_cpu.cpustat;
 | |
| +	cputime_t one_jiffy = jiffies_to_cputime(1);
 | |
| +	cputime_t one_jiffy_scaled = cputime_to_scaled(one_jiffy);
 | |
| +	cputime64_t tmp = cputime_to_cputime64(one_jiffy);
 | |
| +
 | |
| +	p->utime_pc += pc;
 | |
| +	if (p->utime_pc >= 100) {
 | |
| +		p->utime_pc -= 100;
 | |
| +		p->utime = cputime_add(p->utime, one_jiffy);
 | |
| +		p->utimescaled = cputime_add(p->utimescaled, one_jiffy_scaled);
 | |
| +		account_group_user_time(p, one_jiffy);
 | |
| +		acct_update_integrals(p);
 | |
| +	}
 | |
| +	p->se.sum_exec_runtime += ns;
 | |
| +
 | |
| +	if (TASK_NICE(p) > 0 || idleprio_task(p)) {
 | |
| +		rq->nice_pc += pc;
 | |
| +		if (rq->nice_pc >= 100) {
 | |
| +			rq->nice_pc %= 100;
 | |
| +			cpustat->nice = cputime64_add(cpustat->nice, tmp);
 | |
| +		}
 | |
| +	} else {
 | |
| +		rq->user_pc += pc;
 | |
| +		if (rq->user_pc >= 100) {
 | |
| +			rq->user_pc %= 100;
 | |
| +			cpustat->user = cputime64_add(cpustat->user, tmp);
 | |
| +		}
 | |
| +	}
 | |
| +}
 | |
| +
 | |
| +/* Convert nanoseconds to percentage of one tick. */
 | |
| +#define NS_TO_PC(NS)	(NS * 100 / JIFFIES_TO_NS(1))
 | |
| +
 | |
| +/*
 | |
| + * This is called on clock ticks and on context switches.
 | |
| + * Bank in p->se.sum_exec_runtime the ns elapsed since the last tick or switch.
 | |
| + * CPU scheduler quota accounting is also performed here in microseconds.
 | |
| + * The value returned from sched_clock() occasionally gives bogus values so
 | |
| + * some sanity checking is required. Time is supposed to be banked all the
 | |
| + * time so default to half a tick to make up for when sched_clock reverts
 | |
| + * to just returning jiffies, and for hardware that can't do tsc.
 | |
| + */
 | |
| +static void
 | |
| +update_cpu_clock(struct rq *rq, struct task_struct *p, int tick)
 | |
| +{
 | |
| +	long time_diff = rq->clock - p->last_ran;
 | |
| +	long account_ns = rq->clock - rq->timekeep_clock;
 | |
| +	struct task_struct *idle = rq->idle;
 | |
| +	unsigned long account_pc;
 | |
| +
 | |
| +	/*
 | |
| +	 * There should be less than or equal to one jiffy worth, and not
 | |
| +	 * negative/overflow. time_diff is only used for internal scheduler
 | |
| +	 * time_slice accounting.
 | |
| +	 */
 | |
| +	if (time_diff <= 0)
 | |
| +		time_diff = JIFFIES_TO_NS(1) / 2;
 | |
| +	else if (time_diff > JIFFIES_TO_NS(1))
 | |
| +		time_diff = JIFFIES_TO_NS(1);
 | |
| +
 | |
| +	if (unlikely(account_ns < 0))
 | |
| +		account_ns = 0;
 | |
| +
 | |
| +	account_pc = NS_TO_PC(account_ns);
 | |
| +
 | |
| +	if (tick) {
 | |
| +		int user_tick = user_mode(get_irq_regs());
 | |
| +
 | |
| +		/* Accurate tick timekeeping */
 | |
| +		if (user_tick)
 | |
| +			pc_user_time(rq, p, account_pc, account_ns);
 | |
| +		else if (p != idle || (irq_count() != HARDIRQ_OFFSET))
 | |
| +			pc_system_time(rq, p, HARDIRQ_OFFSET,
 | |
| +				       account_pc, account_ns);
 | |
| +		else
 | |
| +			pc_idle_time(rq, account_pc);
 | |
| +	} else {
 | |
| +		/* Accurate subtick timekeeping */
 | |
| +		if (p == idle)
 | |
| +			pc_idle_time(rq, account_pc);
 | |
| +		else
 | |
| +			pc_user_time(rq, p, account_pc, account_ns);
 | |
| +	}
 | |
| +
 | |
| +	/* time_slice accounting is done in usecs to avoid overflow on 32bit */
 | |
| +	if (rq->rq_policy != SCHED_FIFO && p != idle)
 | |
| +		rq->rq_time_slice -= time_diff / 1000;
 | |
| +	p->last_ran = rq->timekeep_clock = rq->clock;
 | |
| +}
 | |
| +
 | |
| +/*
 | |
| + * Return any ns on the sched_clock that have not yet been accounted in
 | |
| + * @p in case that task is currently running.
 | |
| + *
 | |
| + * Called with task_grq_lock() held on @rq.
 | |
| + */
 | |
| +static u64 do_task_delta_exec(struct task_struct *p, struct rq *rq)
 | |
| +{
 | |
| +	u64 ns = 0;
 | |
| +
 | |
| +	if (p == rq->curr) {
 | |
| +		update_rq_clock(rq);
 | |
| +		ns = rq->clock - p->last_ran;
 | |
| +		if ((s64)ns < 0)
 | |
| +			ns = 0;
 | |
| +	}
 | |
| +
 | |
| +	return ns;
 | |
| +}
 | |
| +
 | |
| +unsigned long long task_delta_exec(struct task_struct *p)
 | |
| +{
 | |
| +	unsigned long flags;
 | |
| +	struct rq *rq;
 | |
| +	u64 ns = 0;
 | |
| +
 | |
| +	rq = task_grq_lock(p, &flags);
 | |
| +	ns = do_task_delta_exec(p, rq);
 | |
| +	task_grq_unlock(&flags);
 | |
| +
 | |
| +	return ns;
 | |
| +}
 | |
| +
 | |
| +/*
 | |
| + * Return accounted runtime for the task.
 | |
| + * In case the task is currently running, return the runtime plus current's
 | |
| + * pending runtime that have not been accounted yet.
 | |
| + */
 | |
| +unsigned long long task_sched_runtime(struct task_struct *p)
 | |
| +{
 | |
| +	unsigned long flags;
 | |
| +	struct rq *rq;
 | |
| +	u64 ns = 0;
 | |
| +
 | |
| +	rq = task_grq_lock(p, &flags);
 | |
| +	ns = p->se.sum_exec_runtime + do_task_delta_exec(p, rq);
 | |
| +	task_grq_unlock(&flags);
 | |
| +
 | |
| +	return ns;
 | |
| +}
 | |
| +
 | |
| +/*
 | |
| + * Return sum_exec_runtime for the thread group.
 | |
| + * In case the task is currently running, return the sum plus current's
 | |
| + * pending runtime that have not been accounted yet.
 | |
| + *
 | |
| + * Note that the thread group might have other running tasks as well,
 | |
| + * so the return value not includes other pending runtime that other
 | |
| + * running tasks might have.
 | |
| + */
 | |
| +unsigned long long thread_group_sched_runtime(struct task_struct *p)
 | |
| +{
 | |
| +	struct task_cputime totals;
 | |
| +	unsigned long flags;
 | |
| +	struct rq *rq;
 | |
| +	u64 ns;
 | |
| +
 | |
| +	rq = task_grq_lock(p, &flags);
 | |
| +	thread_group_cputime(p, &totals);
 | |
| +	ns = totals.sum_exec_runtime + do_task_delta_exec(p, rq);
 | |
| +	task_grq_unlock(&flags);
 | |
| +
 | |
| +	return ns;
 | |
| +}
 | |
| +
 | |
| +/* Compatibility crap for removal */
 | |
| +void account_user_time(struct task_struct *p, cputime_t cputime,
 | |
| +		       cputime_t cputime_scaled)
 | |
| +{
 | |
| +}
 | |
| +
 | |
| +void account_idle_time(cputime_t cputime)
 | |
| +{
 | |
| +}
 | |
| +
 | |
| +/*
 | |
| + * Account guest cpu time to a process.
 | |
| + * @p: the process that the cpu time gets accounted to
 | |
| + * @cputime: the cpu time spent in virtual machine since the last update
 | |
| + * @cputime_scaled: cputime scaled by cpu frequency
 | |
| + */
 | |
| +static void account_guest_time(struct task_struct *p, cputime_t cputime,
 | |
| +			       cputime_t cputime_scaled)
 | |
| +{
 | |
| +	cputime64_t tmp;
 | |
| +	struct cpu_usage_stat *cpustat = &kstat_this_cpu.cpustat;
 | |
| +
 | |
| +	tmp = cputime_to_cputime64(cputime);
 | |
| +
 | |
| +	/* Add guest time to process. */
 | |
| +	p->utime = cputime_add(p->utime, cputime);
 | |
| +	p->utimescaled = cputime_add(p->utimescaled, cputime_scaled);
 | |
| +	account_group_user_time(p, cputime);
 | |
| +	p->gtime = cputime_add(p->gtime, cputime);
 | |
| +
 | |
| +	/* Add guest time to cpustat. */
 | |
| +	cpustat->user = cputime64_add(cpustat->user, tmp);
 | |
| +	cpustat->guest = cputime64_add(cpustat->guest, tmp);
 | |
| +}
 | |
| +
 | |
| +/*
 | |
| + * Account system cpu time to a process.
 | |
| + * @p: the process that the cpu time gets accounted to
 | |
| + * @hardirq_offset: the offset to subtract from hardirq_count()
 | |
| + * @cputime: the cpu time spent in kernel space since the last update
 | |
| + * @cputime_scaled: cputime scaled by cpu frequency
 | |
| + * This is for guest only now.
 | |
| + */
 | |
| +void account_system_time(struct task_struct *p, int hardirq_offset,
 | |
| +			 cputime_t cputime, cputime_t cputime_scaled)
 | |
| +{
 | |
| +
 | |
| +	if ((p->flags & PF_VCPU) && (irq_count() - hardirq_offset == 0))
 | |
| +		account_guest_time(p, cputime, cputime_scaled);
 | |
| +}
 | |
| +
 | |
| +/*
 | |
| + * Account for involuntary wait time.
 | |
| + * @steal: the cpu time spent in involuntary wait
 | |
| + */
 | |
| +void account_steal_time(cputime_t cputime)
 | |
| +{
 | |
| +	struct cpu_usage_stat *cpustat = &kstat_this_cpu.cpustat;
 | |
| +	cputime64_t cputime64 = cputime_to_cputime64(cputime);
 | |
| +
 | |
| +	cpustat->steal = cputime64_add(cpustat->steal, cputime64);
 | |
| +}
 | |
| +
 | |
| +/*
 | |
| + * Account for idle time.
 | |
| + * @cputime: the cpu time spent in idle wait
 | |
| + */
 | |
| +static void account_idle_times(cputime_t cputime)
 | |
| +{
 | |
| +	struct cpu_usage_stat *cpustat = &kstat_this_cpu.cpustat;
 | |
| +	cputime64_t cputime64 = cputime_to_cputime64(cputime);
 | |
| +	struct rq *rq = this_rq();
 | |
| +
 | |
| +	if (atomic_read(&rq->nr_iowait) > 0)
 | |
| +		cpustat->iowait = cputime64_add(cpustat->iowait, cputime64);
 | |
| +	else
 | |
| +		cpustat->idle = cputime64_add(cpustat->idle, cputime64);
 | |
| +}
 | |
| +
 | |
| +#ifndef CONFIG_VIRT_CPU_ACCOUNTING
 | |
| +
 | |
| +void account_process_tick(struct task_struct *p, int user_tick)
 | |
| +{
 | |
| +}
 | |
| +
 | |
| +/*
 | |
| + * Account multiple ticks of steal time.
 | |
| + * @p: the process from which the cpu time has been stolen
 | |
| + * @ticks: number of stolen ticks
 | |
| + */
 | |
| +void account_steal_ticks(unsigned long ticks)
 | |
| +{
 | |
| +	account_steal_time(jiffies_to_cputime(ticks));
 | |
| +}
 | |
| +
 | |
| +/*
 | |
| + * Account multiple ticks of idle time.
 | |
| + * @ticks: number of stolen ticks
 | |
| + */
 | |
| +void account_idle_ticks(unsigned long ticks)
 | |
| +{
 | |
| +	account_idle_times(jiffies_to_cputime(ticks));
 | |
| +}
 | |
| +#endif
 | |
| +
 | |
| +/*
 | |
| + * Functions to test for when SCHED_ISO tasks have used their allocated
 | |
| + * quota as real time scheduling and convert them back to SCHED_NORMAL.
 | |
| + * Where possible, the data is tested lockless, to avoid grabbing grq_lock
 | |
| + * because the occasional inaccurate result won't matter. However the
 | |
| + * data is only ever modified under lock.
 | |
| + */
 | |
| +static void set_iso_refractory(void)
 | |
| +{
 | |
| +	grq_lock();
 | |
| +	grq.iso_refractory = 1;
 | |
| +	grq_unlock();
 | |
| +}
 | |
| +
 | |
| +static void clear_iso_refractory(void)
 | |
| +{
 | |
| +	grq_lock();
 | |
| +	grq.iso_refractory = 0;
 | |
| +	grq_unlock();
 | |
| +}
 | |
| +
 | |
| +/*
 | |
| + * Test if SCHED_ISO tasks have run longer than their alloted period as RT
 | |
| + * tasks and set the refractory flag if necessary. There is 10% hysteresis
 | |
| + * for unsetting the flag.
 | |
| + */
 | |
| +static unsigned int test_ret_isorefractory(struct rq *rq)
 | |
| +{
 | |
| +	if (likely(!grq.iso_refractory)) {
 | |
| +		if (grq.iso_ticks / ISO_PERIOD > sched_iso_cpu)
 | |
| +			set_iso_refractory();
 | |
| +	} else {
 | |
| +		if (grq.iso_ticks / ISO_PERIOD < (sched_iso_cpu * 90 / 100))
 | |
| +			clear_iso_refractory();
 | |
| +	}
 | |
| +	return grq.iso_refractory;
 | |
| +}
 | |
| +
 | |
| +static void iso_tick(void)
 | |
| +{
 | |
| +	grq_lock();
 | |
| +	grq.iso_ticks += 100;
 | |
| +	grq_unlock();
 | |
| +}
 | |
| +
 | |
| +/* No SCHED_ISO task was running so decrease rq->iso_ticks */
 | |
| +static inline void no_iso_tick(void)
 | |
| +{
 | |
| +	if (grq.iso_ticks) {
 | |
| +		grq_lock();
 | |
| +		grq.iso_ticks = grq.iso_ticks * (ISO_PERIOD - 1) / ISO_PERIOD;
 | |
| +		grq_unlock();
 | |
| +	}
 | |
| +}
 | |
| +
 | |
| +static int rq_running_iso(struct rq *rq)
 | |
| +{
 | |
| +	return rq->rq_prio == ISO_PRIO;
 | |
| +}
 | |
| +
 | |
| +/* This manages tasks that have run out of timeslice during a scheduler_tick */
 | |
| +static void task_running_tick(struct rq *rq)
 | |
| +{
 | |
| +	struct task_struct *p;
 | |
| +
 | |
| +	/*
 | |
| +	 * If a SCHED_ISO task is running we increment the iso_ticks. In
 | |
| +	 * order to prevent SCHED_ISO tasks from causing starvation in the
 | |
| +	 * presence of true RT tasks we account those as iso_ticks as well.
 | |
| +	 */
 | |
| +	if ((rt_queue(rq) || (iso_queue(rq) && !grq.iso_refractory))) {
 | |
| +		if (grq.iso_ticks <= (ISO_PERIOD * 100) - 100)
 | |
| +			iso_tick();
 | |
| +	} else
 | |
| +		no_iso_tick();
 | |
| +
 | |
| +	if (iso_queue(rq)) {
 | |
| +		if (unlikely(test_ret_isorefractory(rq))) {
 | |
| +			if (rq_running_iso(rq)) {
 | |
| +				/*
 | |
| +				 * SCHED_ISO task is running as RT and limit
 | |
| +				 * has been hit. Force it to reschedule as
 | |
| +				 * SCHED_NORMAL by zeroing its time_slice
 | |
| +				 */
 | |
| +				rq->rq_time_slice = 0;
 | |
| +			}
 | |
| +		}
 | |
| +	}
 | |
| +
 | |
| +	/* SCHED_FIFO tasks never run out of timeslice. */
 | |
| +	if (rq_idle(rq) || rq->rq_time_slice > 0 || rq->rq_policy == SCHED_FIFO)
 | |
| +		return;
 | |
| +
 | |
| +	/* p->rt.time_slice <= 0. We only modify task_struct under grq lock */
 | |
| +	grq_lock();
 | |
| +	p = rq->curr;
 | |
| +	if (likely(task_running(p))) {
 | |
| +		requeue_task(p);
 | |
| +		set_tsk_need_resched(p);
 | |
| +	}
 | |
| +	grq_unlock();
 | |
| +}
 | |
| +
 | |
| +void wake_up_idle_cpu(int cpu);
 | |
| +
 | |
| +/*
 | |
| + * This function gets called by the timer code, with HZ frequency.
 | |
| + * We call it with interrupts disabled. The data modified is all
 | |
| + * local to struct rq so we don't need to grab grq lock.
 | |
| + */
 | |
| +void scheduler_tick(void)
 | |
| +{
 | |
| +	int cpu = smp_processor_id();
 | |
| +	struct rq *rq = cpu_rq(cpu);
 | |
| +
 | |
| +	sched_clock_tick();
 | |
| +	update_rq_clock(rq);
 | |
| +	update_cpu_clock(rq, rq->curr, 1);
 | |
| +	if (!rq_idle(rq))
 | |
| +		task_running_tick(rq);
 | |
| +	else {
 | |
| +		no_iso_tick();
 | |
| +		if (unlikely(queued_notrunning()))
 | |
| +			set_tsk_need_resched(rq->idle);
 | |
| +	}
 | |
| +}
 | |
| +
 | |
| +notrace unsigned long get_parent_ip(unsigned long addr)
 | |
| +{
 | |
| +	if (in_lock_functions(addr)) {
 | |
| +		addr = CALLER_ADDR2;
 | |
| +		if (in_lock_functions(addr))
 | |
| +			addr = CALLER_ADDR3;
 | |
| +	}
 | |
| +	return addr;
 | |
| +}
 | |
| +
 | |
| +#if defined(CONFIG_PREEMPT) && (defined(CONFIG_DEBUG_PREEMPT) || \
 | |
| +				defined(CONFIG_PREEMPT_TRACER))
 | |
| +void __kprobes add_preempt_count(int val)
 | |
| +{
 | |
| +#ifdef CONFIG_DEBUG_PREEMPT
 | |
| +	/*
 | |
| +	 * Underflow?
 | |
| +	 */
 | |
| +	if (DEBUG_LOCKS_WARN_ON((preempt_count() < 0)))
 | |
| +		return;
 | |
| +#endif
 | |
| +	preempt_count() += val;
 | |
| +#ifdef CONFIG_DEBUG_PREEMPT
 | |
| +	/*
 | |
| +	 * Spinlock count overflowing soon?
 | |
| +	 */
 | |
| +	DEBUG_LOCKS_WARN_ON((preempt_count() & PREEMPT_MASK) >=
 | |
| +				PREEMPT_MASK - 10);
 | |
| +#endif
 | |
| +	if (preempt_count() == val)
 | |
| +		trace_preempt_off(CALLER_ADDR0, get_parent_ip(CALLER_ADDR1));
 | |
| +}
 | |
| +EXPORT_SYMBOL(add_preempt_count);
 | |
| +
 | |
| +void __kprobes sub_preempt_count(int val)
 | |
| +{
 | |
| +#ifdef CONFIG_DEBUG_PREEMPT
 | |
| +	/*
 | |
| +	 * Underflow?
 | |
| +	 */
 | |
| +	if (DEBUG_LOCKS_WARN_ON(val > preempt_count()))
 | |
| +		return;
 | |
| +	/*
 | |
| +	 * Is the spinlock portion underflowing?
 | |
| +	 */
 | |
| +	if (DEBUG_LOCKS_WARN_ON((val < PREEMPT_MASK) &&
 | |
| +			!(preempt_count() & PREEMPT_MASK)))
 | |
| +		return;
 | |
| +#endif
 | |
| +
 | |
| +	if (preempt_count() == val)
 | |
| +		trace_preempt_on(CALLER_ADDR0, get_parent_ip(CALLER_ADDR1));
 | |
| +	preempt_count() -= val;
 | |
| +}
 | |
| +EXPORT_SYMBOL(sub_preempt_count);
 | |
| +#endif
 | |
| +
 | |
| +/*
 | |
| + * Deadline is "now" in jiffies + (offset by priority). Setting the deadline
 | |
| + * is the key to everything. It distributes cpu fairly amongst tasks of the
 | |
| + * same nice value, it proportions cpu according to nice level, it means the
 | |
| + * task that last woke up the longest ago has the earliest deadline, thus
 | |
| + * ensuring that interactive tasks get low latency on wake up.
 | |
| + */
 | |
| +static inline int prio_deadline_diff(struct task_struct *p)
 | |
| +{
 | |
| +	return (pratio(p) * rr_interval * HZ / 1000 / 100) ? : 1;
 | |
| +}
 | |
| +
 | |
| +static inline int longest_deadline(void)
 | |
| +{
 | |
| +	return (prio_ratios[39] * rr_interval * HZ / 1000 / 100);
 | |
| +}
 | |
| +
 | |
| +/*
 | |
| + * SCHED_IDLE tasks still have a deadline set, but offset by to nice +19.
 | |
| + * This allows nice levels to work between IDLEPRIO tasks and gives a
 | |
| + * deadline longer than nice +19 for when they're scheduled as SCHED_NORMAL
 | |
| + * tasks.
 | |
| + */
 | |
| +static inline void time_slice_expired(struct task_struct *p)
 | |
| +{
 | |
| +	reset_first_time_slice(p);
 | |
| +	p->rt.time_slice = timeslice();
 | |
| +	p->deadline = jiffies + prio_deadline_diff(p);
 | |
| +	if (idleprio_task(p))
 | |
| +		p->deadline += longest_deadline();
 | |
| +}
 | |
| +
 | |
| +static inline void check_deadline(struct task_struct *p)
 | |
| +{
 | |
| +	if (p->rt.time_slice <= 0)
 | |
| +		time_slice_expired(p);
 | |
| +}
 | |
| +
 | |
| +/*
 | |
| + * O(n) lookup of all tasks in the global runqueue. The real brainfuck
 | |
| + * of lock contention and O(n). It's not really O(n) as only the queued,
 | |
| + * but not running tasks are scanned, and is O(n) queued in the worst case
 | |
| + * scenario only because the right task can be found before scanning all of
 | |
| + * them.
 | |
| + * Tasks are selected in this order:
 | |
| + * Real time tasks are selected purely by their static priority and in the
 | |
| + * order they were queued, so the lowest value idx, and the first queued task
 | |
| + * of that priority value is chosen.
 | |
| + * If no real time tasks are found, the SCHED_ISO priority is checked, and
 | |
| + * all SCHED_ISO tasks have the same priority value, so they're selected by
 | |
| + * the earliest deadline value.
 | |
| + * If no SCHED_ISO tasks are found, SCHED_NORMAL tasks are selected by the
 | |
| + * earliest deadline.
 | |
| + * Finally if no SCHED_NORMAL tasks are found, SCHED_IDLEPRIO tasks are
 | |
| + * selected by the earliest deadline.
 | |
| + */
 | |
| +static inline struct
 | |
| +task_struct *earliest_deadline_task(struct rq *rq, struct task_struct *idle)
 | |
| +{
 | |
| +	unsigned long dl, earliest_deadline = 0; /* Initialise to silence compiler */
 | |
| +	struct task_struct *p, *edt;
 | |
| +	unsigned int cpu = rq->cpu;
 | |
| +	struct list_head *queue;
 | |
| +	int idx = 0;
 | |
| +
 | |
| +	edt = idle;
 | |
| +retry:
 | |
| +	idx = find_next_bit(grq.prio_bitmap, PRIO_LIMIT, idx);
 | |
| +	if (idx >= PRIO_LIMIT)
 | |
| +		goto out;
 | |
| +	queue = &grq.queue[idx];
 | |
| +	list_for_each_entry(p, queue, rt.run_list) {
 | |
| +		/* Make sure cpu affinity is ok */
 | |
| +		if (!cpu_isset(cpu, p->cpus_allowed))
 | |
| +			continue;
 | |
| +		if (idx < MAX_RT_PRIO) {
 | |
| +			/* We found an rt task */
 | |
| +			edt = p;
 | |
| +			goto out_take;
 | |
| +		}
 | |
| +
 | |
| +		/*
 | |
| +		 * No rt task, select the earliest deadline task now.
 | |
| +		 * On the 1st run the 2nd condition is never used, so
 | |
| +		 * there is no need to initialise earliest_deadline
 | |
| +		 * before. Normalise all old deadlines to now.
 | |
| +		 */
 | |
| +		if (time_before(p->deadline, jiffies))
 | |
| +			dl = jiffies;
 | |
| +		else
 | |
| +			dl = p->deadline;
 | |
| +
 | |
| +		if (edt == idle ||
 | |
| +		    time_before(dl, earliest_deadline)) {
 | |
| +			earliest_deadline = dl;
 | |
| +			edt = p;
 | |
| +		}
 | |
| +	}
 | |
| +	if (edt == idle) {
 | |
| +		if (++idx < PRIO_LIMIT)
 | |
| +			goto retry;
 | |
| +		goto out;
 | |
| +	}
 | |
| +out_take:
 | |
| +	take_task(rq, edt);
 | |
| +out:
 | |
| +	return edt;
 | |
| +}
 | |
| +
 | |
| +#ifdef CONFIG_SMP
 | |
| +static inline void set_cpuidle_map(unsigned long cpu)
 | |
| +{
 | |
| +	cpu_set(cpu, grq.cpu_idle_map);
 | |
| +}
 | |
| +
 | |
| +static inline void clear_cpuidle_map(unsigned long cpu)
 | |
| +{
 | |
| +	cpu_clear(cpu, grq.cpu_idle_map);
 | |
| +}
 | |
| +
 | |
| +#else /* CONFIG_SMP */
 | |
| +static inline void set_cpuidle_map(unsigned long cpu)
 | |
| +{
 | |
| +}
 | |
| +
 | |
| +static inline void clear_cpuidle_map(unsigned long cpu)
 | |
| +{
 | |
| +}
 | |
| +#endif /* !CONFIG_SMP */
 | |
| +
 | |
| +/*
 | |
| + * Print scheduling while atomic bug:
 | |
| + */
 | |
| +static noinline void __schedule_bug(struct task_struct *prev)
 | |
| +{
 | |
| +	struct pt_regs *regs = get_irq_regs();
 | |
| +
 | |
| +	printk(KERN_ERR "BUG: scheduling while atomic: %s/%d/0x%08x\n",
 | |
| +		prev->comm, prev->pid, preempt_count());
 | |
| +
 | |
| +	debug_show_held_locks(prev);
 | |
| +	print_modules();
 | |
| +	if (irqs_disabled())
 | |
| +		print_irqtrace_events(prev);
 | |
| +
 | |
| +	if (regs)
 | |
| +		show_regs(regs);
 | |
| +	else
 | |
| +		dump_stack();
 | |
| +}
 | |
| +
 | |
| +/*
 | |
| + * Various schedule()-time debugging checks and statistics:
 | |
| + */
 | |
| +static inline void schedule_debug(struct task_struct *prev)
 | |
| +{
 | |
| +	/*
 | |
| +	 * Test if we are atomic. Since do_exit() needs to call into
 | |
| +	 * schedule() atomically, we ignore that path for now.
 | |
| +	 * Otherwise, whine if we are scheduling when we should not be.
 | |
| +	 */
 | |
| +	if (unlikely(in_atomic_preempt_off() && !prev->exit_state))
 | |
| +		__schedule_bug(prev);
 | |
| +
 | |
| +	profile_hit(SCHED_PROFILING, __builtin_return_address(0));
 | |
| +
 | |
| +	schedstat_inc(this_rq(), sched_count);
 | |
| +#ifdef CONFIG_SCHEDSTATS
 | |
| +	if (unlikely(prev->lock_depth >= 0)) {
 | |
| +		schedstat_inc(this_rq(), bkl_count);
 | |
| +		schedstat_inc(prev, sched_info.bkl_count);
 | |
| +	}
 | |
| +#endif
 | |
| +}
 | |
| +
 | |
| +/*
 | |
| + * schedule() is the main scheduler function.
 | |
| + */
 | |
| +asmlinkage void __sched __schedule(void)
 | |
| +{
 | |
| +	struct task_struct *prev, *next, *idle;
 | |
| +	int deactivate = 0, cpu;
 | |
| +	long *switch_count;
 | |
| +	struct rq *rq;
 | |
| +	u64 now;
 | |
| +
 | |
| +	cpu = smp_processor_id();
 | |
| +	rq = this_rq();
 | |
| +	rcu_qsctr_inc(cpu);
 | |
| +	prev = rq->curr;
 | |
| +	switch_count = &prev->nivcsw;
 | |
| +
 | |
| +	release_kernel_lock(prev);
 | |
| +need_resched_nonpreemptible:
 | |
| +
 | |
| +	schedule_debug(prev);
 | |
| +	idle = rq->idle;
 | |
| +	/*
 | |
| +	 * The idle thread is not allowed to schedule!
 | |
| +	 * Remove this check after it has been exercised a bit.
 | |
| +	 */
 | |
| +	if (unlikely(prev == idle) && prev->state != TASK_RUNNING) {
 | |
| +		printk(KERN_ERR "bad: scheduling from the idle thread!\n");
 | |
| +		dump_stack();
 | |
| +	}
 | |
| +
 | |
| +	grq_lock_irq();
 | |
| +	update_rq_clock(rq);
 | |
| +	now = rq->clock;
 | |
| +	update_cpu_clock(rq, prev, 0);
 | |
| +
 | |
| +	clear_tsk_need_resched(prev);
 | |
| +
 | |
| +	if (prev->state && !(preempt_count() & PREEMPT_ACTIVE)) {
 | |
| +		if (unlikely(signal_pending_state(prev->state, prev)))
 | |
| +			prev->state = TASK_RUNNING;
 | |
| +		else
 | |
| +			deactivate = 1;
 | |
| +		switch_count = &prev->nvcsw;
 | |
| +	}
 | |
| +
 | |
| +	if (prev != idle) {
 | |
| +		/* Update all the information stored on struct rq */
 | |
| +		prev->rt.time_slice = rq->rq_time_slice;
 | |
| +		prev->deadline = rq->rq_deadline;
 | |
| +		check_deadline(prev);
 | |
| +		return_task(prev, deactivate);
 | |
| +	}
 | |
| +
 | |
| +	if (likely(queued_notrunning())) {
 | |
| +		next = earliest_deadline_task(rq, idle);
 | |
| +	} else {
 | |
| +		next = idle;
 | |
| +		schedstat_inc(rq, sched_goidle);
 | |
| +	}
 | |
| +
 | |
| +	if (next == rq->idle)
 | |
| +		set_cpuidle_map(cpu);
 | |
| +	else
 | |
| +		clear_cpuidle_map(cpu);
 | |
| +
 | |
| +	prefetch(next);
 | |
| +	prefetch_stack(next);
 | |
| +
 | |
| +	prev->timestamp = prev->last_ran = now;
 | |
| +
 | |
| +	if (likely(prev != next)) {
 | |
| +		rq->rq_time_slice = next->rt.time_slice;
 | |
| +		rq->rq_deadline = next->deadline;
 | |
| +		rq->rq_prio = next->prio;
 | |
| +
 | |
| +		sched_info_switch(prev, next);
 | |
| +		grq.nr_switches++;
 | |
| +		next->oncpu = 1;
 | |
| +		prev->oncpu = 0;
 | |
| +		rq->curr = next;
 | |
| +		++*switch_count;
 | |
| +
 | |
| +		context_switch(rq, prev, next); /* unlocks the rq */
 | |
| +		/*
 | |
| +		 * the context switch might have flipped the stack from under
 | |
| +		 * us, hence refresh the local variables.
 | |
| +		 */
 | |
| +		cpu = smp_processor_id();
 | |
| +		rq = cpu_rq(cpu);
 | |
| +	} else
 | |
| +		grq_unlock_irq();
 | |
| +
 | |
| +	if (unlikely(reacquire_kernel_lock(current) < 0))
 | |
| +		goto need_resched_nonpreemptible;
 | |
| +}
 | |
| +
 | |
| +asmlinkage void __sched schedule(void)
 | |
| +{
 | |
| +need_resched:
 | |
| +	preempt_disable();
 | |
| +	__schedule();
 | |
| +	preempt_enable_no_resched();
 | |
| +	if (unlikely(test_thread_flag(TIF_NEED_RESCHED)))
 | |
| +		goto need_resched;
 | |
| +}
 | |
| +EXPORT_SYMBOL(schedule);
 | |
| +
 | |
| +#ifdef CONFIG_SMP
 | |
| +int mutex_spin_on_owner(struct mutex *lock, struct thread_info *owner)
 | |
| +{
 | |
| +	return 0;
 | |
| +}
 | |
| +#endif
 | |
| +
 | |
| +#ifdef CONFIG_PREEMPT
 | |
| +/*
 | |
| + * this is the entry point to schedule() from in-kernel preemption
 | |
| + * off of preempt_enable. Kernel preemptions off return from interrupt
 | |
| + * occur there and call schedule directly.
 | |
| + */
 | |
| +asmlinkage void __sched preempt_schedule(void)
 | |
| +{
 | |
| +	struct thread_info *ti = current_thread_info();
 | |
| +
 | |
| +	/*
 | |
| +	 * If there is a non-zero preempt_count or interrupts are disabled,
 | |
| +	 * we do not want to preempt the current task. Just return..
 | |
| +	 */
 | |
| +	if (likely(ti->preempt_count || irqs_disabled()))
 | |
| +		return;
 | |
| +
 | |
| +	do {
 | |
| +		add_preempt_count(PREEMPT_ACTIVE);
 | |
| +		schedule();
 | |
| +		sub_preempt_count(PREEMPT_ACTIVE);
 | |
| +
 | |
| +		/*
 | |
| +		 * Check again in case we missed a preemption opportunity
 | |
| +		 * between schedule and now.
 | |
| +		 */
 | |
| +		barrier();
 | |
| +	} while (need_resched());
 | |
| +}
 | |
| +EXPORT_SYMBOL(preempt_schedule);
 | |
| +
 | |
| +/*
 | |
| + * this is the entry point to schedule() from kernel preemption
 | |
| + * off of irq context.
 | |
| + * Note, that this is called and return with irqs disabled. This will
 | |
| + * protect us against recursive calling from irq.
 | |
| + */
 | |
| +asmlinkage void __sched preempt_schedule_irq(void)
 | |
| +{
 | |
| +	struct thread_info *ti = current_thread_info();
 | |
| +
 | |
| +	/* Catch callers which need to be fixed */
 | |
| +	BUG_ON(ti->preempt_count || !irqs_disabled());
 | |
| +
 | |
| +	do {
 | |
| +		add_preempt_count(PREEMPT_ACTIVE);
 | |
| +		local_irq_enable();
 | |
| +		schedule();
 | |
| +		local_irq_disable();
 | |
| +		sub_preempt_count(PREEMPT_ACTIVE);
 | |
| +
 | |
| +		/*
 | |
| +		 * Check again in case we missed a preemption opportunity
 | |
| +		 * between schedule and now.
 | |
| +		 */
 | |
| +		barrier();
 | |
| +	} while (need_resched());
 | |
| +}
 | |
| +
 | |
| +#endif /* CONFIG_PREEMPT */
 | |
| +
 | |
| +int default_wake_function(wait_queue_t *curr, unsigned mode, int sync,
 | |
| +			  void *key)
 | |
| +{
 | |
| +	return try_to_wake_up(curr->private, mode, sync);
 | |
| +}
 | |
| +EXPORT_SYMBOL(default_wake_function);
 | |
| +
 | |
| +/*
 | |
| + * The core wakeup function.  Non-exclusive wakeups (nr_exclusive == 0) just
 | |
| + * wake everything up.  If it's an exclusive wakeup (nr_exclusive == small +ve
 | |
| + * number) then we wake all the non-exclusive tasks and one exclusive task.
 | |
| + *
 | |
| + * There are circumstances in which we can try to wake a task which has already
 | |
| + * started to run but is not in state TASK_RUNNING.  try_to_wake_up() returns
 | |
| + * zero in this (rare) case, and we handle it by continuing to scan the queue.
 | |
| + */
 | |
| +void __wake_up_common(wait_queue_head_t *q, unsigned int mode,
 | |
| +		      int nr_exclusive, int sync, void *key)
 | |
| +{
 | |
| +	struct list_head *tmp, *next;
 | |
| +
 | |
| +	list_for_each_safe(tmp, next, &q->task_list) {
 | |
| +		wait_queue_t *curr = list_entry(tmp, wait_queue_t, task_list);
 | |
| +		unsigned flags = curr->flags;
 | |
| +
 | |
| +		if (curr->func(curr, mode, sync, key) &&
 | |
| +				(flags & WQ_FLAG_EXCLUSIVE) && !--nr_exclusive)
 | |
| +			break;
 | |
| +	}
 | |
| +}
 | |
| +
 | |
| +/**
 | |
| + * __wake_up - wake up threads blocked on a waitqueue.
 | |
| + * @q: the waitqueue
 | |
| + * @mode: which threads
 | |
| + * @nr_exclusive: how many wake-one or wake-many threads to wake up
 | |
| + * @key: is directly passed to the wakeup function
 | |
| + *
 | |
| + * It may be assumed that this function implies a write memory barrier before
 | |
| + * changing the task state if and only if any tasks are woken up.
 | |
| + */
 | |
| +void __wake_up(wait_queue_head_t *q, unsigned int mode,
 | |
| +			int nr_exclusive, void *key)
 | |
| +{
 | |
| +	unsigned long flags;
 | |
| +
 | |
| +	spin_lock_irqsave(&q->lock, flags);
 | |
| +	__wake_up_common(q, mode, nr_exclusive, 0, key);
 | |
| +	spin_unlock_irqrestore(&q->lock, flags);
 | |
| +}
 | |
| +EXPORT_SYMBOL(__wake_up);
 | |
| +
 | |
| +/*
 | |
| + * Same as __wake_up but called with the spinlock in wait_queue_head_t held.
 | |
| + */
 | |
| +void __wake_up_locked(wait_queue_head_t *q, unsigned int mode)
 | |
| +{
 | |
| +	__wake_up_common(q, mode, 1, 0, NULL);
 | |
| +}
 | |
| +
 | |
| +void __wake_up_locked_key(wait_queue_head_t *q, unsigned int mode, void *key)
 | |
| +{
 | |
| +	__wake_up_common(q, mode, 1, 0, key);
 | |
| +}
 | |
| +
 | |
| +/**
 | |
| + * __wake_up_sync_key - wake up threads blocked on a waitqueue.
 | |
| + * @q: the waitqueue
 | |
| + * @mode: which threads
 | |
| + * @nr_exclusive: how many wake-one or wake-many threads to wake up
 | |
| + * @key: opaque value to be passed to wakeup targets
 | |
| + *
 | |
| + * The sync wakeup differs that the waker knows that it will schedule
 | |
| + * away soon, so while the target thread will be woken up, it will not
 | |
| + * be migrated to another CPU - ie. the two threads are 'synchronized'
 | |
| + * with each other. This can prevent needless bouncing between CPUs.
 | |
| + *
 | |
| + * On UP it can prevent extra preemption.
 | |
| + *
 | |
| + * It may be assumed that this function implies a write memory barrier before
 | |
| + * changing the task state if and only if any tasks are woken up.
 | |
| + */
 | |
| +void __wake_up_sync_key(wait_queue_head_t *q, unsigned int mode,
 | |
| +			int nr_exclusive, void *key)
 | |
| +{
 | |
| +	unsigned long flags;
 | |
| +	int sync = 1;
 | |
| +
 | |
| +	if (unlikely(!q))
 | |
| +		return;
 | |
| +
 | |
| +	if (unlikely(!nr_exclusive))
 | |
| +		sync = 0;
 | |
| +
 | |
| +	spin_lock_irqsave(&q->lock, flags);
 | |
| +	__wake_up_common(q, mode, nr_exclusive, sync, key);
 | |
| +	spin_unlock_irqrestore(&q->lock, flags);
 | |
| +}
 | |
| +EXPORT_SYMBOL_GPL(__wake_up_sync_key);
 | |
| +
 | |
| +/**
 | |
| + * __wake_up_sync - wake up threads blocked on a waitqueue.
 | |
| + * @q: the waitqueue
 | |
| + * @mode: which threads
 | |
| + * @nr_exclusive: how many wake-one or wake-many threads to wake up
 | |
| + *
 | |
| + * The sync wakeup differs that the waker knows that it will schedule
 | |
| + * away soon, so while the target thread will be woken up, it will not
 | |
| + * be migrated to another CPU - ie. the two threads are 'synchronized'
 | |
| + * with each other. This can prevent needless bouncing between CPUs.
 | |
| + *
 | |
| + * On UP it can prevent extra preemption.
 | |
| + */
 | |
| +void __wake_up_sync(wait_queue_head_t *q, unsigned int mode, int nr_exclusive)
 | |
| +{
 | |
| +	unsigned long flags;
 | |
| +	int sync = 1;
 | |
| +
 | |
| +	if (unlikely(!q))
 | |
| +		return;
 | |
| +
 | |
| +	if (unlikely(!nr_exclusive))
 | |
| +		sync = 0;
 | |
| +
 | |
| +	spin_lock_irqsave(&q->lock, flags);
 | |
| +	__wake_up_common(q, mode, nr_exclusive, sync, NULL);
 | |
| +	spin_unlock_irqrestore(&q->lock, flags);
 | |
| +}
 | |
| +EXPORT_SYMBOL_GPL(__wake_up_sync);	/* For internal use only */
 | |
| +
 | |
| +/**
 | |
| + * complete: - signals a single thread waiting on this completion
 | |
| + * @x:  holds the state of this particular completion
 | |
| + *
 | |
| + * This will wake up a single thread waiting on this completion. Threads will be
 | |
| + * awakened in the same order in which they were queued.
 | |
| + *
 | |
| + * See also complete_all(), wait_for_completion() and related routines.
 | |
| + *
 | |
| + * It may be assumed that this function implies a write memory barrier before
 | |
| + * changing the task state if and only if any tasks are woken up.
 | |
| + */
 | |
| +void complete(struct completion *x)
 | |
| +{
 | |
| +	unsigned long flags;
 | |
| +
 | |
| +	spin_lock_irqsave(&x->wait.lock, flags);
 | |
| +	x->done++;
 | |
| +	__wake_up_common(&x->wait, TASK_NORMAL, 1, 0, NULL);
 | |
| +	spin_unlock_irqrestore(&x->wait.lock, flags);
 | |
| +}
 | |
| +EXPORT_SYMBOL(complete);
 | |
| +
 | |
| +/**
 | |
| + * complete_all: - signals all threads waiting on this completion
 | |
| + * @x:  holds the state of this particular completion
 | |
| + *
 | |
| + * This will wake up all threads waiting on this particular completion event.
 | |
| + *
 | |
| + * It may be assumed that this function implies a write memory barrier before
 | |
| + * changing the task state if and only if any tasks are woken up.
 | |
| + */
 | |
| +void complete_all(struct completion *x)
 | |
| +{
 | |
| +	unsigned long flags;
 | |
| +
 | |
| +	spin_lock_irqsave(&x->wait.lock, flags);
 | |
| +	x->done += UINT_MAX/2;
 | |
| +	__wake_up_common(&x->wait, TASK_NORMAL, 0, 0, NULL);
 | |
| +	spin_unlock_irqrestore(&x->wait.lock, flags);
 | |
| +}
 | |
| +EXPORT_SYMBOL(complete_all);
 | |
| +
 | |
| +static inline long __sched
 | |
| +do_wait_for_common(struct completion *x, long timeout, int state)
 | |
| +{
 | |
| +	if (!x->done) {
 | |
| +		DECLARE_WAITQUEUE(wait, current);
 | |
| +
 | |
| +		wait.flags |= WQ_FLAG_EXCLUSIVE;
 | |
| +		__add_wait_queue_tail(&x->wait, &wait);
 | |
| +		do {
 | |
| +			if (signal_pending_state(state, current)) {
 | |
| +				timeout = -ERESTARTSYS;
 | |
| +				break;
 | |
| +			}
 | |
| +			__set_current_state(state);
 | |
| +			spin_unlock_irq(&x->wait.lock);
 | |
| +			timeout = schedule_timeout(timeout);
 | |
| +			spin_lock_irq(&x->wait.lock);
 | |
| +		} while (!x->done && timeout);
 | |
| +		__remove_wait_queue(&x->wait, &wait);
 | |
| +		if (!x->done)
 | |
| +			return timeout;
 | |
| +	}
 | |
| +	x->done--;
 | |
| +	return timeout ?: 1;
 | |
| +}
 | |
| +
 | |
| +static long __sched
 | |
| +wait_for_common(struct completion *x, long timeout, int state)
 | |
| +{
 | |
| +	might_sleep();
 | |
| +
 | |
| +	spin_lock_irq(&x->wait.lock);
 | |
| +	timeout = do_wait_for_common(x, timeout, state);
 | |
| +	spin_unlock_irq(&x->wait.lock);
 | |
| +	return timeout;
 | |
| +}
 | |
| +
 | |
| +/**
 | |
| + * wait_for_completion: - waits for completion of a task
 | |
| + * @x:  holds the state of this particular completion
 | |
| + *
 | |
| + * This waits to be signaled for completion of a specific task. It is NOT
 | |
| + * interruptible and there is no timeout.
 | |
| + *
 | |
| + * See also similar routines (i.e. wait_for_completion_timeout()) with timeout
 | |
| + * and interrupt capability. Also see complete().
 | |
| + */
 | |
| +void __sched wait_for_completion(struct completion *x)
 | |
| +{
 | |
| +	wait_for_common(x, MAX_SCHEDULE_TIMEOUT, TASK_UNINTERRUPTIBLE);
 | |
| +}
 | |
| +EXPORT_SYMBOL(wait_for_completion);
 | |
| +
 | |
| +/**
 | |
| + * wait_for_completion_timeout: - waits for completion of a task (w/timeout)
 | |
| + * @x:  holds the state of this particular completion
 | |
| + * @timeout:  timeout value in jiffies
 | |
| + *
 | |
| + * This waits for either a completion of a specific task to be signaled or for a
 | |
| + * specified timeout to expire. The timeout is in jiffies. It is not
 | |
| + * interruptible.
 | |
| + */
 | |
| +unsigned long __sched
 | |
| +wait_for_completion_timeout(struct completion *x, unsigned long timeout)
 | |
| +{
 | |
| +	return wait_for_common(x, timeout, TASK_UNINTERRUPTIBLE);
 | |
| +}
 | |
| +EXPORT_SYMBOL(wait_for_completion_timeout);
 | |
| +
 | |
| +/**
 | |
| + * wait_for_completion_interruptible: - waits for completion of a task (w/intr)
 | |
| + * @x:  holds the state of this particular completion
 | |
| + *
 | |
| + * This waits for completion of a specific task to be signaled. It is
 | |
| + * interruptible.
 | |
| + */
 | |
| +int __sched wait_for_completion_interruptible(struct completion *x)
 | |
| +{
 | |
| +	long t = wait_for_common(x, MAX_SCHEDULE_TIMEOUT, TASK_INTERRUPTIBLE);
 | |
| +	if (t == -ERESTARTSYS)
 | |
| +		return t;
 | |
| +	return 0;
 | |
| +}
 | |
| +EXPORT_SYMBOL(wait_for_completion_interruptible);
 | |
| +
 | |
| +/**
 | |
| + * wait_for_completion_interruptible_timeout: - waits for completion (w/(to,intr))
 | |
| + * @x:  holds the state of this particular completion
 | |
| + * @timeout:  timeout value in jiffies
 | |
| + *
 | |
| + * This waits for either a completion of a specific task to be signaled or for a
 | |
| + * specified timeout to expire. It is interruptible. The timeout is in jiffies.
 | |
| + */
 | |
| +unsigned long __sched
 | |
| +wait_for_completion_interruptible_timeout(struct completion *x,
 | |
| +					  unsigned long timeout)
 | |
| +{
 | |
| +	return wait_for_common(x, timeout, TASK_INTERRUPTIBLE);
 | |
| +}
 | |
| +EXPORT_SYMBOL(wait_for_completion_interruptible_timeout);
 | |
| +
 | |
| +/**
 | |
| + * wait_for_completion_killable: - waits for completion of a task (killable)
 | |
| + * @x:  holds the state of this particular completion
 | |
| + *
 | |
| + * This waits to be signaled for completion of a specific task. It can be
 | |
| + * interrupted by a kill signal.
 | |
| + */
 | |
| +int __sched wait_for_completion_killable(struct completion *x)
 | |
| +{
 | |
| +	long t = wait_for_common(x, MAX_SCHEDULE_TIMEOUT, TASK_KILLABLE);
 | |
| +	if (t == -ERESTARTSYS)
 | |
| +		return t;
 | |
| +	return 0;
 | |
| +}
 | |
| +EXPORT_SYMBOL(wait_for_completion_killable);
 | |
| +
 | |
| +/**
 | |
| + *	try_wait_for_completion - try to decrement a completion without blocking
 | |
| + *	@x:	completion structure
 | |
| + *
 | |
| + *	Returns: 0 if a decrement cannot be done without blocking
 | |
| + *		 1 if a decrement succeeded.
 | |
| + *
 | |
| + *	If a completion is being used as a counting completion,
 | |
| + *	attempt to decrement the counter without blocking. This
 | |
| + *	enables us to avoid waiting if the resource the completion
 | |
| + *	is protecting is not available.
 | |
| + */
 | |
| +bool try_wait_for_completion(struct completion *x)
 | |
| +{
 | |
| +	int ret = 1;
 | |
| +
 | |
| +	spin_lock_irq(&x->wait.lock);
 | |
| +	if (!x->done)
 | |
| +		ret = 0;
 | |
| +	else
 | |
| +		x->done--;
 | |
| +	spin_unlock_irq(&x->wait.lock);
 | |
| +	return ret;
 | |
| +}
 | |
| +EXPORT_SYMBOL(try_wait_for_completion);
 | |
| +
 | |
| +/**
 | |
| + *	completion_done - Test to see if a completion has any waiters
 | |
| + *	@x:	completion structure
 | |
| + *
 | |
| + *	Returns: 0 if there are waiters (wait_for_completion() in progress)
 | |
| + *		 1 if there are no waiters.
 | |
| + *
 | |
| + */
 | |
| +bool completion_done(struct completion *x)
 | |
| +{
 | |
| +	int ret = 1;
 | |
| +
 | |
| +	spin_lock_irq(&x->wait.lock);
 | |
| +	if (!x->done)
 | |
| +		ret = 0;
 | |
| +	spin_unlock_irq(&x->wait.lock);
 | |
| +	return ret;
 | |
| +}
 | |
| +EXPORT_SYMBOL(completion_done);
 | |
| +
 | |
| +static long __sched
 | |
| +sleep_on_common(wait_queue_head_t *q, int state, long timeout)
 | |
| +{
 | |
| +	unsigned long flags;
 | |
| +	wait_queue_t wait;
 | |
| +
 | |
| +	init_waitqueue_entry(&wait, current);
 | |
| +
 | |
| +	__set_current_state(state);
 | |
| +
 | |
| +	spin_lock_irqsave(&q->lock, flags);
 | |
| +	__add_wait_queue(q, &wait);
 | |
| +	spin_unlock(&q->lock);
 | |
| +	timeout = schedule_timeout(timeout);
 | |
| +	spin_lock_irq(&q->lock);
 | |
| +	__remove_wait_queue(q, &wait);
 | |
| +	spin_unlock_irqrestore(&q->lock, flags);
 | |
| +
 | |
| +	return timeout;
 | |
| +}
 | |
| +
 | |
| +void __sched interruptible_sleep_on(wait_queue_head_t *q)
 | |
| +{
 | |
| +	sleep_on_common(q, TASK_INTERRUPTIBLE, MAX_SCHEDULE_TIMEOUT);
 | |
| +}
 | |
| +EXPORT_SYMBOL(interruptible_sleep_on);
 | |
| +
 | |
| +long __sched
 | |
| +interruptible_sleep_on_timeout(wait_queue_head_t *q, long timeout)
 | |
| +{
 | |
| +	return sleep_on_common(q, TASK_INTERRUPTIBLE, timeout);
 | |
| +}
 | |
| +EXPORT_SYMBOL(interruptible_sleep_on_timeout);
 | |
| +
 | |
| +void __sched sleep_on(wait_queue_head_t *q)
 | |
| +{
 | |
| +	sleep_on_common(q, TASK_UNINTERRUPTIBLE, MAX_SCHEDULE_TIMEOUT);
 | |
| +}
 | |
| +EXPORT_SYMBOL(sleep_on);
 | |
| +
 | |
| +long __sched sleep_on_timeout(wait_queue_head_t *q, long timeout)
 | |
| +{
 | |
| +	return sleep_on_common(q, TASK_UNINTERRUPTIBLE, timeout);
 | |
| +}
 | |
| +EXPORT_SYMBOL(sleep_on_timeout);
 | |
| +
 | |
| +#ifdef CONFIG_RT_MUTEXES
 | |
| +
 | |
| +/*
 | |
| + * rt_mutex_setprio - set the current priority of a task
 | |
| + * @p: task
 | |
| + * @prio: prio value (kernel-internal form)
 | |
| + *
 | |
| + * This function changes the 'effective' priority of a task. It does
 | |
| + * not touch ->normal_prio like __setscheduler().
 | |
| + *
 | |
| + * Used by the rt_mutex code to implement priority inheritance logic.
 | |
| + */
 | |
| +void rt_mutex_setprio(struct task_struct *p, int prio)
 | |
| +{
 | |
| +	unsigned long flags;
 | |
| +	int queued, oldprio;
 | |
| +	struct rq *rq;
 | |
| +
 | |
| +	BUG_ON(prio < 0 || prio > MAX_PRIO);
 | |
| +
 | |
| +	rq = time_task_grq_lock(p, &flags);
 | |
| +
 | |
| +	oldprio = p->prio;
 | |
| +	queued = task_queued_only(p);
 | |
| +	if (queued)
 | |
| +		dequeue_task(p);
 | |
| +	p->prio = prio;
 | |
| +	if (task_running(p) && prio > oldprio)
 | |
| +		resched_task(p);
 | |
| +	if (queued) {
 | |
| +		enqueue_task(p);
 | |
| +		try_preempt(p);
 | |
| +	}
 | |
| +
 | |
| +	task_grq_unlock(&flags);
 | |
| +}
 | |
| +
 | |
| +#endif
 | |
| +
 | |
| +/*
 | |
| + * Adjust the deadline for when the priority is to change, before it's
 | |
| + * changed.
 | |
| + */
 | |
| +static void adjust_deadline(struct task_struct *p, int new_prio)
 | |
| +{
 | |
| +	p->deadline += (prio_ratios[USER_PRIO(new_prio)] - pratio(p)) *
 | |
| +			rr_interval * HZ / 1000 / 100;
 | |
| +}
 | |
| +
 | |
| +void set_user_nice(struct task_struct *p, long nice)
 | |
| +{
 | |
| +	int queued, new_static;
 | |
| +	unsigned long flags;
 | |
| +	struct rq *rq;
 | |
| +
 | |
| +	if (TASK_NICE(p) == nice || nice < -20 || nice > 19)
 | |
| +		return;
 | |
| +	new_static = NICE_TO_PRIO(nice);
 | |
| +	/*
 | |
| +	 * We have to be careful, if called from sys_setpriority(),
 | |
| +	 * the task might be in the middle of scheduling on another CPU.
 | |
| +	 */
 | |
| +	rq = time_task_grq_lock(p, &flags);
 | |
| +	/*
 | |
| +	 * The RT priorities are set via sched_setscheduler(), but we still
 | |
| +	 * allow the 'normal' nice value to be set - but as expected
 | |
| +	 * it wont have any effect on scheduling until the task is
 | |
| +	 * not SCHED_NORMAL/SCHED_BATCH:
 | |
| +	 */
 | |
| +	if (has_rt_policy(p)) {
 | |
| +		p->static_prio = new_static;
 | |
| +		goto out_unlock;
 | |
| +	}
 | |
| +	queued = task_queued_only(p);
 | |
| +	/*
 | |
| +	 * If p is actually running, we don't need to do anything when
 | |
| +	 * changing the priority because the grq is unaffected.
 | |
| +	 */
 | |
| +	if (queued)
 | |
| +		dequeue_task(p);
 | |
| +
 | |
| +	adjust_deadline(p, new_static);
 | |
| +	p->static_prio = new_static;
 | |
| +	p->prio = effective_prio(p);
 | |
| +
 | |
| +	if (queued) {
 | |
| +		enqueue_task(p);
 | |
| +		try_preempt(p);
 | |
| +	}
 | |
| +
 | |
| +	/* Just resched the task, schedule() will know what to do. */
 | |
| +	if (task_running(p))
 | |
| +		resched_task(p);
 | |
| +out_unlock:
 | |
| +	task_grq_unlock(&flags);
 | |
| +}
 | |
| +EXPORT_SYMBOL(set_user_nice);
 | |
| +
 | |
| +/*
 | |
| + * can_nice - check if a task can reduce its nice value
 | |
| + * @p: task
 | |
| + * @nice: nice value
 | |
| + */
 | |
| +int can_nice(const struct task_struct *p, const int nice)
 | |
| +{
 | |
| +	/* convert nice value [19,-20] to rlimit style value [1,40] */
 | |
| +	int nice_rlim = 20 - nice;
 | |
| +
 | |
| +	return (nice_rlim <= p->signal->rlim[RLIMIT_NICE].rlim_cur ||
 | |
| +		capable(CAP_SYS_NICE));
 | |
| +}
 | |
| +
 | |
| +#ifdef __ARCH_WANT_SYS_NICE
 | |
| +
 | |
| +/*
 | |
| + * sys_nice - change the priority of the current process.
 | |
| + * @increment: priority increment
 | |
| + *
 | |
| + * sys_setpriority is a more generic, but much slower function that
 | |
| + * does similar things.
 | |
| + */
 | |
| +SYSCALL_DEFINE1(nice, int, increment)
 | |
| +{
 | |
| +	long nice, retval;
 | |
| +
 | |
| +	/*
 | |
| +	 * Setpriority might change our priority at the same moment.
 | |
| +	 * We don't have to worry. Conceptually one call occurs first
 | |
| +	 * and we have a single winner.
 | |
| +	 */
 | |
| +	if (increment < -40)
 | |
| +		increment = -40;
 | |
| +	if (increment > 40)
 | |
| +		increment = 40;
 | |
| +
 | |
| +	nice = TASK_NICE(current) + increment;
 | |
| +	if (nice < -20)
 | |
| +		nice = -20;
 | |
| +	if (nice > 19)
 | |
| +		nice = 19;
 | |
| +
 | |
| +	if (increment < 0 && !can_nice(current, nice))
 | |
| +		return -EPERM;
 | |
| +
 | |
| +	retval = security_task_setnice(current, nice);
 | |
| +	if (retval)
 | |
| +		return retval;
 | |
| +
 | |
| +	set_user_nice(current, nice);
 | |
| +	return 0;
 | |
| +}
 | |
| +
 | |
| +#endif
 | |
| +
 | |
| +/**
 | |
| + * task_prio - return the priority value of a given task.
 | |
| + * @p: the task in question.
 | |
| + *
 | |
| + * This is the priority value as seen by users in /proc.
 | |
| + * RT tasks are offset by -100. Normal tasks are centered
 | |
| + * around 1, value goes from 0 (SCHED_ISO) up to 82 (nice +19
 | |
| + * SCHED_IDLE).
 | |
| + */
 | |
| +int task_prio(const struct task_struct *p)
 | |
| +{
 | |
| +	int delta, prio = p->prio - MAX_RT_PRIO;
 | |
| +
 | |
| +	/* rt tasks and iso tasks */
 | |
| +	if (prio <= 0)
 | |
| +		goto out;
 | |
| +
 | |
| +	delta = (p->deadline - jiffies) * 40 / longest_deadline();
 | |
| +	if (delta > 0 && delta <= 80)
 | |
| +		prio += delta;
 | |
| +out:
 | |
| +	return prio;
 | |
| +}
 | |
| +
 | |
| +/**
 | |
| + * task_nice - return the nice value of a given task.
 | |
| + * @p: the task in question.
 | |
| + */
 | |
| +int task_nice(const struct task_struct *p)
 | |
| +{
 | |
| +	return TASK_NICE(p);
 | |
| +}
 | |
| +EXPORT_SYMBOL_GPL(task_nice);
 | |
| +
 | |
| +/**
 | |
| + * idle_cpu - is a given cpu idle currently?
 | |
| + * @cpu: the processor in question.
 | |
| + */
 | |
| +int idle_cpu(int cpu)
 | |
| +{
 | |
| +	return cpu_curr(cpu) == cpu_rq(cpu)->idle;
 | |
| +}
 | |
| +
 | |
| +/**
 | |
| + * idle_task - return the idle task for a given cpu.
 | |
| + * @cpu: the processor in question.
 | |
| + */
 | |
| +struct task_struct *idle_task(int cpu)
 | |
| +{
 | |
| +	return cpu_rq(cpu)->idle;
 | |
| +}
 | |
| +
 | |
| +/**
 | |
| + * find_process_by_pid - find a process with a matching PID value.
 | |
| + * @pid: the pid in question.
 | |
| + */
 | |
| +static inline struct task_struct *find_process_by_pid(pid_t pid)
 | |
| +{
 | |
| +	return pid ? find_task_by_vpid(pid) : current;
 | |
| +}
 | |
| +
 | |
| +/* Actually do priority change: must hold grq lock. */
 | |
| +static void __setscheduler(struct task_struct *p, int policy, int prio)
 | |
| +{
 | |
| +	BUG_ON(task_queued_only(p));
 | |
| +
 | |
| +	p->policy = policy;
 | |
| +	p->rt_priority = prio;
 | |
| +	p->normal_prio = normal_prio(p);
 | |
| +	/* we are holding p->pi_lock already */
 | |
| +	p->prio = rt_mutex_getprio(p);
 | |
| +	/*
 | |
| +	 * Reschedule if running. schedule() will know if it can continue
 | |
| +	 * running or not.
 | |
| +	 */
 | |
| +	if (task_running(p))
 | |
| +		resched_task(p);
 | |
| +}
 | |
| +
 | |
| +/*
 | |
| + * check the target process has a UID that matches the current process's
 | |
| + */
 | |
| +static bool check_same_owner(struct task_struct *p)
 | |
| +{
 | |
| +	const struct cred *cred = current_cred(), *pcred;
 | |
| +	bool match;
 | |
| +
 | |
| +	rcu_read_lock();
 | |
| +	pcred = __task_cred(p);
 | |
| +	match = (cred->euid == pcred->euid ||
 | |
| +		 cred->euid == pcred->uid);
 | |
| +	rcu_read_unlock();
 | |
| +	return match;
 | |
| +}
 | |
| +
 | |
| +static int __sched_setscheduler(struct task_struct *p, int policy,
 | |
| +		       struct sched_param *param, bool user)
 | |
| +{
 | |
| +	struct sched_param zero_param = { .sched_priority = 0 };
 | |
| +	int queued, retval, oldprio, oldpolicy = -1;
 | |
| +	unsigned long flags, rlim_rtprio = 0;
 | |
| +	struct rq *rq;
 | |
| +
 | |
| +	/* may grab non-irq protected spin_locks */
 | |
| +	BUG_ON(in_interrupt());
 | |
| +
 | |
| +	if (is_rt_policy(policy) && !capable(CAP_SYS_NICE)) {
 | |
| +		unsigned long lflags;
 | |
| +
 | |
| +		if (!lock_task_sighand(p, &lflags))
 | |
| +			return -ESRCH;
 | |
| +		rlim_rtprio = p->signal->rlim[RLIMIT_RTPRIO].rlim_cur;
 | |
| +		unlock_task_sighand(p, &lflags);
 | |
| +		if (rlim_rtprio)
 | |
| +			goto recheck;
 | |
| +		/*
 | |
| +		 * If the caller requested an RT policy without having the
 | |
| +		 * necessary rights, we downgrade the policy to SCHED_ISO.
 | |
| +		 * We also set the parameter to zero to pass the checks.
 | |
| +		 */
 | |
| +		policy = SCHED_ISO;
 | |
| +		param = &zero_param;
 | |
| +	}
 | |
| +recheck:
 | |
| +	/* double check policy once rq lock held */
 | |
| +	if (policy < 0)
 | |
| +		policy = oldpolicy = p->policy;
 | |
| +	else if (!SCHED_RANGE(policy))
 | |
| +		return -EINVAL;
 | |
| +	/*
 | |
| +	 * Valid priorities for SCHED_FIFO and SCHED_RR are
 | |
| +	 * 1..MAX_USER_RT_PRIO-1, valid priority for SCHED_NORMAL and
 | |
| +	 * SCHED_BATCH is 0.
 | |
| +	 */
 | |
| +	if (param->sched_priority < 0 ||
 | |
| +	    (p->mm && param->sched_priority > MAX_USER_RT_PRIO-1) ||
 | |
| +	    (!p->mm && param->sched_priority > MAX_RT_PRIO-1))
 | |
| +		return -EINVAL;
 | |
| +	if (is_rt_policy(policy) != (param->sched_priority != 0))
 | |
| +		return -EINVAL;
 | |
| +
 | |
| +	/*
 | |
| +	 * Allow unprivileged RT tasks to decrease priority:
 | |
| +	 */
 | |
| +	if (user && !capable(CAP_SYS_NICE)) {
 | |
| +		if (is_rt_policy(policy)) {
 | |
| +			/* can't set/change the rt policy */
 | |
| +			if (policy != p->policy && !rlim_rtprio)
 | |
| +				return -EPERM;
 | |
| +
 | |
| +			/* can't increase priority */
 | |
| +			if (param->sched_priority > p->rt_priority &&
 | |
| +			    param->sched_priority > rlim_rtprio)
 | |
| +				return -EPERM;
 | |
| +		} else {
 | |
| +			switch (p->policy) {
 | |
| +				/*
 | |
| +				 * Can only downgrade policies but not back to
 | |
| +				 * SCHED_NORMAL
 | |
| +				 */
 | |
| +				case SCHED_ISO:
 | |
| +					if (policy == SCHED_ISO)
 | |
| +						goto out;
 | |
| +					if (policy == SCHED_NORMAL)
 | |
| +						return -EPERM;
 | |
| +					break;
 | |
| +				case SCHED_BATCH:
 | |
| +					if (policy == SCHED_BATCH)
 | |
| +						goto out;
 | |
| +					if (policy != SCHED_IDLE)
 | |
| +					    	return -EPERM;
 | |
| +					break;
 | |
| +				case SCHED_IDLE:
 | |
| +					if (policy == SCHED_IDLE)
 | |
| +						goto out;
 | |
| +					return -EPERM;
 | |
| +				default:
 | |
| +					break;
 | |
| +			}
 | |
| +		}
 | |
| +
 | |
| +		/* can't change other user's priorities */
 | |
| +		if (!check_same_owner(p))
 | |
| +			return -EPERM;
 | |
| +	}
 | |
| +
 | |
| +	retval = security_task_setscheduler(p, policy, param);
 | |
| +	if (retval)
 | |
| +		return retval;
 | |
| +	/*
 | |
| +	 * make sure no PI-waiters arrive (or leave) while we are
 | |
| +	 * changing the priority of the task:
 | |
| +	 */
 | |
| +	spin_lock_irqsave(&p->pi_lock, flags);
 | |
| +	/*
 | |
| +	 * To be able to change p->policy safely, the apropriate
 | |
| +	 * runqueue lock must be held.
 | |
| +	 */
 | |
| +	rq = __task_grq_lock(p);
 | |
| +	/* recheck policy now with rq lock held */
 | |
| +	if (unlikely(oldpolicy != -1 && oldpolicy != p->policy)) {
 | |
| +		__task_grq_unlock();
 | |
| +		spin_unlock_irqrestore(&p->pi_lock, flags);
 | |
| +		policy = oldpolicy = -1;
 | |
| +		goto recheck;
 | |
| +	}
 | |
| +	update_rq_clock(rq);
 | |
| +	queued = task_queued_only(p);
 | |
| +	if (queued)
 | |
| +		dequeue_task(p);
 | |
| +	oldprio = p->prio;
 | |
| +	__setscheduler(p, policy, param->sched_priority);
 | |
| +	if (queued) {
 | |
| +		enqueue_task(p);
 | |
| +		try_preempt(p);
 | |
| +	}
 | |
| +	__task_grq_unlock();
 | |
| +	spin_unlock_irqrestore(&p->pi_lock, flags);
 | |
| +
 | |
| +	rt_mutex_adjust_pi(p);
 | |
| +out:
 | |
| +	return 0;
 | |
| +}
 | |
| +
 | |
| +/**
 | |
| + * sched_setscheduler - change the scheduling policy and/or RT priority of a thread.
 | |
| + * @p: the task in question.
 | |
| + * @policy: new policy.
 | |
| + * @param: structure containing the new RT priority.
 | |
| + *
 | |
| + * NOTE that the task may be already dead.
 | |
| + */
 | |
| +int sched_setscheduler(struct task_struct *p, int policy,
 | |
| +		       struct sched_param *param)
 | |
| +{
 | |
| +	return __sched_setscheduler(p, policy, param, true);
 | |
| +}
 | |
| +
 | |
| +EXPORT_SYMBOL_GPL(sched_setscheduler);
 | |
| +
 | |
| +/**
 | |
| + * sched_setscheduler_nocheck - change the scheduling policy and/or RT priority of a thread from kernelspace.
 | |
| + * @p: the task in question.
 | |
| + * @policy: new policy.
 | |
| + * @param: structure containing the new RT priority.
 | |
| + *
 | |
| + * Just like sched_setscheduler, only don't bother checking if the
 | |
| + * current context has permission.  For example, this is needed in
 | |
| + * stop_machine(): we create temporary high priority worker threads,
 | |
| + * but our caller might not have that capability.
 | |
| + */
 | |
| +int sched_setscheduler_nocheck(struct task_struct *p, int policy,
 | |
| +			       struct sched_param *param)
 | |
| +{
 | |
| +	return __sched_setscheduler(p, policy, param, false);
 | |
| +}
 | |
| +
 | |
| +static int
 | |
| +do_sched_setscheduler(pid_t pid, int policy, struct sched_param __user *param)
 | |
| +{
 | |
| +	struct sched_param lparam;
 | |
| +	struct task_struct *p;
 | |
| +	int retval;
 | |
| +
 | |
| +	if (!param || pid < 0)
 | |
| +		return -EINVAL;
 | |
| +	if (copy_from_user(&lparam, param, sizeof(struct sched_param)))
 | |
| +		return -EFAULT;
 | |
| +
 | |
| +	rcu_read_lock();
 | |
| +	retval = -ESRCH;
 | |
| +	p = find_process_by_pid(pid);
 | |
| +	if (p != NULL)
 | |
| +		retval = sched_setscheduler(p, policy, &lparam);
 | |
| +	rcu_read_unlock();
 | |
| +
 | |
| +	return retval;
 | |
| +}
 | |
| +
 | |
| +/**
 | |
| + * sys_sched_setscheduler - set/change the scheduler policy and RT priority
 | |
| + * @pid: the pid in question.
 | |
| + * @policy: new policy.
 | |
| + * @param: structure containing the new RT priority.
 | |
| + */
 | |
| +asmlinkage long sys_sched_setscheduler(pid_t pid, int policy,
 | |
| +				       struct sched_param __user *param)
 | |
| +{
 | |
| +	/* negative values for policy are not valid */
 | |
| +	if (policy < 0)
 | |
| +		return -EINVAL;
 | |
| +
 | |
| +	return do_sched_setscheduler(pid, policy, param);
 | |
| +}
 | |
| +
 | |
| +/**
 | |
| + * sys_sched_setparam - set/change the RT priority of a thread
 | |
| + * @pid: the pid in question.
 | |
| + * @param: structure containing the new RT priority.
 | |
| + */
 | |
| +SYSCALL_DEFINE2(sched_setparam, pid_t, pid, struct sched_param __user *, param)
 | |
| +{
 | |
| +	return do_sched_setscheduler(pid, -1, param);
 | |
| +}
 | |
| +
 | |
| +/**
 | |
| + * sys_sched_getscheduler - get the policy (scheduling class) of a thread
 | |
| + * @pid: the pid in question.
 | |
| + */
 | |
| +SYSCALL_DEFINE1(sched_getscheduler, pid_t, pid)
 | |
| +{
 | |
| +	struct task_struct *p;
 | |
| +	int retval = -EINVAL;
 | |
| +
 | |
| +	if (pid < 0)
 | |
| +		goto out_nounlock;
 | |
| +
 | |
| +	retval = -ESRCH;
 | |
| +	read_lock(&tasklist_lock);
 | |
| +	p = find_process_by_pid(pid);
 | |
| +	if (p) {
 | |
| +		retval = security_task_getscheduler(p);
 | |
| +		if (!retval)
 | |
| +			retval = p->policy;
 | |
| +	}
 | |
| +	read_unlock(&tasklist_lock);
 | |
| +
 | |
| +out_nounlock:
 | |
| +	return retval;
 | |
| +}
 | |
| +
 | |
| +/**
 | |
| + * sys_sched_getscheduler - get the RT priority of a thread
 | |
| + * @pid: the pid in question.
 | |
| + * @param: structure containing the RT priority.
 | |
| + */
 | |
| +SYSCALL_DEFINE2(sched_getparam, pid_t, pid, struct sched_param __user *, param)
 | |
| +{
 | |
| +	struct sched_param lp;
 | |
| +	struct task_struct *p;
 | |
| +	int retval = -EINVAL;
 | |
| +
 | |
| +	if (!param || pid < 0)
 | |
| +		goto out_nounlock;
 | |
| +
 | |
| +	read_lock(&tasklist_lock);
 | |
| +	p = find_process_by_pid(pid);
 | |
| +	retval = -ESRCH;
 | |
| +	if (!p)
 | |
| +		goto out_unlock;
 | |
| +
 | |
| +	retval = security_task_getscheduler(p);
 | |
| +	if (retval)
 | |
| +		goto out_unlock;
 | |
| +
 | |
| +	lp.sched_priority = p->rt_priority;
 | |
| +	read_unlock(&tasklist_lock);
 | |
| +
 | |
| +	/*
 | |
| +	 * This one might sleep, we cannot do it with a spinlock held ...
 | |
| +	 */
 | |
| +	retval = copy_to_user(param, &lp, sizeof(*param)) ? -EFAULT : 0;
 | |
| +
 | |
| +out_nounlock:
 | |
| +	return retval;
 | |
| +
 | |
| +out_unlock:
 | |
| +	read_unlock(&tasklist_lock);
 | |
| +	return retval;
 | |
| +}
 | |
| +
 | |
| +long sched_setaffinity(pid_t pid, const struct cpumask *in_mask)
 | |
| +{
 | |
| +	cpumask_var_t cpus_allowed, new_mask;
 | |
| +	struct task_struct *p;
 | |
| +	int retval;
 | |
| +
 | |
| +	get_online_cpus();
 | |
| +	read_lock(&tasklist_lock);
 | |
| +
 | |
| +	p = find_process_by_pid(pid);
 | |
| +	if (!p) {
 | |
| +		read_unlock(&tasklist_lock);
 | |
| +		put_online_cpus();
 | |
| +		return -ESRCH;
 | |
| +	}
 | |
| +
 | |
| +	/*
 | |
| +	 * It is not safe to call set_cpus_allowed with the
 | |
| +	 * tasklist_lock held. We will bump the task_struct's
 | |
| +	 * usage count and then drop tasklist_lock.
 | |
| +	 */
 | |
| +	get_task_struct(p);
 | |
| +	read_unlock(&tasklist_lock);
 | |
| +
 | |
| +	if (!alloc_cpumask_var(&cpus_allowed, GFP_KERNEL)) {
 | |
| +		retval = -ENOMEM;
 | |
| +		goto out_put_task;
 | |
| +	}
 | |
| +	if (!alloc_cpumask_var(&new_mask, GFP_KERNEL)) {
 | |
| +		retval = -ENOMEM;
 | |
| +		goto out_free_cpus_allowed;
 | |
| +	}
 | |
| +	retval = -EPERM;
 | |
| +	if (!check_same_owner(p) && !capable(CAP_SYS_NICE))
 | |
| +		goto out_unlock;
 | |
| +
 | |
| +	retval = security_task_setscheduler(p, 0, NULL);
 | |
| +	if (retval)
 | |
| +		goto out_unlock;
 | |
| +
 | |
| +	cpuset_cpus_allowed(p, cpus_allowed);
 | |
| +	cpumask_and(new_mask, in_mask, cpus_allowed);
 | |
| +again:
 | |
| +	retval = set_cpus_allowed_ptr(p, new_mask);
 | |
| +
 | |
| +	if (!retval) {
 | |
| +		cpuset_cpus_allowed(p, cpus_allowed);
 | |
| +		if (!cpumask_subset(new_mask, cpus_allowed)) {
 | |
| +			/*
 | |
| +			 * We must have raced with a concurrent cpuset
 | |
| +			 * update. Just reset the cpus_allowed to the
 | |
| +			 * cpuset's cpus_allowed
 | |
| +			 */
 | |
| +			cpumask_copy(new_mask, cpus_allowed);
 | |
| +			goto again;
 | |
| +		}
 | |
| +	}
 | |
| +out_unlock:
 | |
| +	free_cpumask_var(new_mask);
 | |
| +out_free_cpus_allowed:
 | |
| +	free_cpumask_var(cpus_allowed);
 | |
| +out_put_task:
 | |
| +	put_task_struct(p);
 | |
| +	put_online_cpus();
 | |
| +	return retval;
 | |
| +}
 | |
| +
 | |
| +static int get_user_cpu_mask(unsigned long __user *user_mask_ptr, unsigned len,
 | |
| +			     cpumask_t *new_mask)
 | |
| +{
 | |
| +	if (len < sizeof(cpumask_t)) {
 | |
| +		memset(new_mask, 0, sizeof(cpumask_t));
 | |
| +	} else if (len > sizeof(cpumask_t)) {
 | |
| +		len = sizeof(cpumask_t);
 | |
| +	}
 | |
| +	return copy_from_user(new_mask, user_mask_ptr, len) ? -EFAULT : 0;
 | |
| +}
 | |
| +
 | |
| +
 | |
| +/**
 | |
| + * sys_sched_setaffinity - set the cpu affinity of a process
 | |
| + * @pid: pid of the process
 | |
| + * @len: length in bytes of the bitmask pointed to by user_mask_ptr
 | |
| + * @user_mask_ptr: user-space pointer to the new cpu mask
 | |
| + */
 | |
| +SYSCALL_DEFINE3(sched_setaffinity, pid_t, pid, unsigned int, len,
 | |
| +		unsigned long __user *, user_mask_ptr)
 | |
| +{
 | |
| +	cpumask_var_t new_mask;
 | |
| +	int retval;
 | |
| +
 | |
| +	if (!alloc_cpumask_var(&new_mask, GFP_KERNEL))
 | |
| +		return -ENOMEM;
 | |
| +
 | |
| +	retval = get_user_cpu_mask(user_mask_ptr, len, new_mask);
 | |
| +	if (retval == 0)
 | |
| +		retval = sched_setaffinity(pid, new_mask);
 | |
| +	free_cpumask_var(new_mask);
 | |
| +	return retval;
 | |
| +}
 | |
| +
 | |
| +long sched_getaffinity(pid_t pid, cpumask_t *mask)
 | |
| +{
 | |
| +	struct task_struct *p;
 | |
| +	int retval;
 | |
| +
 | |
| +	mutex_lock(&sched_hotcpu_mutex);
 | |
| +	read_lock(&tasklist_lock);
 | |
| +
 | |
| +	retval = -ESRCH;
 | |
| +	p = find_process_by_pid(pid);
 | |
| +	if (!p)
 | |
| +		goto out_unlock;
 | |
| +
 | |
| +	retval = security_task_getscheduler(p);
 | |
| +	if (retval)
 | |
| +		goto out_unlock;
 | |
| +
 | |
| +	cpus_and(*mask, p->cpus_allowed, cpu_online_map);
 | |
| +
 | |
| +out_unlock:
 | |
| +	read_unlock(&tasklist_lock);
 | |
| +	mutex_unlock(&sched_hotcpu_mutex);
 | |
| +	if (retval)
 | |
| +		return retval;
 | |
| +
 | |
| +	return 0;
 | |
| +}
 | |
| +
 | |
| +/**
 | |
| + * sys_sched_getaffinity - get the cpu affinity of a process
 | |
| + * @pid: pid of the process
 | |
| + * @len: length in bytes of the bitmask pointed to by user_mask_ptr
 | |
| + * @user_mask_ptr: user-space pointer to hold the current cpu mask
 | |
| + */
 | |
| +SYSCALL_DEFINE3(sched_getaffinity, pid_t, pid, unsigned int, len,
 | |
| +		unsigned long __user *, user_mask_ptr)
 | |
| +{
 | |
| +	int ret;
 | |
| +	cpumask_var_t mask;
 | |
| +
 | |
| +	if (len < cpumask_size())
 | |
| +		return -EINVAL;
 | |
| +
 | |
| +	if (!alloc_cpumask_var(&mask, GFP_KERNEL))
 | |
| +		return -ENOMEM;
 | |
| +
 | |
| +	ret = sched_getaffinity(pid, mask);
 | |
| +	if (ret == 0) {
 | |
| +		if (copy_to_user(user_mask_ptr, mask, cpumask_size()))
 | |
| +			ret = -EFAULT;
 | |
| +		else
 | |
| +			ret = cpumask_size();
 | |
| +	}
 | |
| +	free_cpumask_var(mask);
 | |
| +
 | |
| +	return ret;
 | |
| +}
 | |
| +
 | |
| +/**
 | |
| + * sys_sched_yield - yield the current processor to other threads.
 | |
| + *
 | |
| + * This function yields the current CPU to other tasks. It does this by
 | |
| + * refilling the timeslice, resetting the deadline and scheduling away.
 | |
| + */
 | |
| +SYSCALL_DEFINE0(sched_yield)
 | |
| +{
 | |
| +	struct task_struct *p;
 | |
| +
 | |
| +	grq_lock_irq();
 | |
| +	p = current;
 | |
| +	schedstat_inc(this_rq(), yld_count);
 | |
| +	update_rq_clock(task_rq(p));
 | |
| +	time_slice_expired(p);
 | |
| +	requeue_task(p);
 | |
| +
 | |
| +	/*
 | |
| +	 * Since we are going to call schedule() anyway, there's
 | |
| +	 * no need to preempt or enable interrupts:
 | |
| +	 */
 | |
| +	__release(grq.lock);
 | |
| +	spin_release(&grq.lock.dep_map, 1, _THIS_IP_);
 | |
| +	_raw_spin_unlock(&grq.lock);
 | |
| +	preempt_enable_no_resched();
 | |
| +
 | |
| +	schedule();
 | |
| +
 | |
| +	return 0;
 | |
| +}
 | |
| +
 | |
| +static inline int should_resched(void)
 | |
| +{
 | |
| +	return need_resched() && !(preempt_count() & PREEMPT_ACTIVE);
 | |
| +}
 | |
| +
 | |
| +static void __cond_resched(void)
 | |
| +{
 | |
| +#ifdef CONFIG_DEBUG_SPINLOCK_SLEEP
 | |
| +	__might_sleep(__FILE__, __LINE__);
 | |
| +#endif
 | |
| +	/*
 | |
| +	 * The BKS might be reacquired before we have dropped
 | |
| +	 * PREEMPT_ACTIVE, which could trigger a second
 | |
| +	 * cond_resched() call.
 | |
| +	 */
 | |
| +	do {
 | |
| +		add_preempt_count(PREEMPT_ACTIVE);
 | |
| +		schedule();
 | |
| +		sub_preempt_count(PREEMPT_ACTIVE);
 | |
| +	} while (need_resched());
 | |
| +}
 | |
| +
 | |
| +int __sched _cond_resched(void)
 | |
| +{
 | |
| +	if (should_resched()) {
 | |
| +		__cond_resched();
 | |
| +		return 1;
 | |
| +	}
 | |
| +	return 0;
 | |
| +}
 | |
| +EXPORT_SYMBOL(_cond_resched);
 | |
| +
 | |
| +/*
 | |
| + * cond_resched_lock() - if a reschedule is pending, drop the given lock,
 | |
| + * call schedule, and on return reacquire the lock.
 | |
| + *
 | |
| + * This works OK both with and without CONFIG_PREEMPT.  We do strange low-level
 | |
| + * operations here to prevent schedule() from being called twice (once via
 | |
| + * spin_unlock(), once by hand).
 | |
| + */
 | |
| +int cond_resched_lock(spinlock_t *lock)
 | |
| +{
 | |
| +	int resched = should_resched();
 | |
| +	int ret = 0;
 | |
| +
 | |
| +	if (spin_needbreak(lock) || resched) {
 | |
| +		spin_unlock(lock);
 | |
| +		if (resched)
 | |
| +			__cond_resched();
 | |
| +		else
 | |
| +			cpu_relax();
 | |
| +		ret = 1;
 | |
| +		spin_lock(lock);
 | |
| +	}
 | |
| +	return ret;
 | |
| +}
 | |
| +EXPORT_SYMBOL(cond_resched_lock);
 | |
| +
 | |
| +int __sched cond_resched_softirq(void)
 | |
| +{
 | |
| +	BUG_ON(!in_softirq());
 | |
| +
 | |
| +	if (should_resched()) {
 | |
| +		local_bh_enable();
 | |
| +		__cond_resched();
 | |
| +		local_bh_disable();
 | |
| +		return 1;
 | |
| +	}
 | |
| +	return 0;
 | |
| +}
 | |
| +EXPORT_SYMBOL(cond_resched_softirq);
 | |
| +
 | |
| +/**
 | |
| + * yield - yield the current processor to other threads.
 | |
| + *
 | |
| + * This is a shortcut for kernel-space yielding - it marks the
 | |
| + * thread runnable and calls sys_sched_yield().
 | |
| + */
 | |
| +void __sched yield(void)
 | |
| +{
 | |
| +	set_current_state(TASK_RUNNING);
 | |
| +	sys_sched_yield();
 | |
| +}
 | |
| +EXPORT_SYMBOL(yield);
 | |
| +
 | |
| +/*
 | |
| + * This task is about to go to sleep on IO.  Increment rq->nr_iowait so
 | |
| + * that process accounting knows that this is a task in IO wait state.
 | |
| + *
 | |
| + * But don't do that if it is a deliberate, throttling IO wait (this task
 | |
| + * has set its backing_dev_info: the queue against which it should throttle)
 | |
| + */
 | |
| +void __sched io_schedule(void)
 | |
| +{
 | |
| +	struct rq *rq = &__raw_get_cpu_var(runqueues);
 | |
| +
 | |
| +	delayacct_blkio_start();
 | |
| +	atomic_inc(&rq->nr_iowait);
 | |
| +	schedule();
 | |
| +	atomic_dec(&rq->nr_iowait);
 | |
| +	delayacct_blkio_end();
 | |
| +}
 | |
| +EXPORT_SYMBOL(io_schedule);
 | |
| +
 | |
| +long __sched io_schedule_timeout(long timeout)
 | |
| +{
 | |
| +	struct rq *rq = &__raw_get_cpu_var(runqueues);
 | |
| +	long ret;
 | |
| +
 | |
| +	delayacct_blkio_start();
 | |
| +	atomic_inc(&rq->nr_iowait);
 | |
| +	ret = schedule_timeout(timeout);
 | |
| +	atomic_dec(&rq->nr_iowait);
 | |
| +	delayacct_blkio_end();
 | |
| +	return ret;
 | |
| +}
 | |
| +
 | |
| +/**
 | |
| + * sys_sched_get_priority_max - return maximum RT priority.
 | |
| + * @policy: scheduling class.
 | |
| + *
 | |
| + * this syscall returns the maximum rt_priority that can be used
 | |
| + * by a given scheduling class.
 | |
| + */
 | |
| +SYSCALL_DEFINE1(sched_get_priority_max, int, policy)
 | |
| +{
 | |
| +	int ret = -EINVAL;
 | |
| +
 | |
| +	switch (policy) {
 | |
| +	case SCHED_FIFO:
 | |
| +	case SCHED_RR:
 | |
| +		ret = MAX_USER_RT_PRIO-1;
 | |
| +		break;
 | |
| +	case SCHED_NORMAL:
 | |
| +	case SCHED_BATCH:
 | |
| +	case SCHED_ISO:
 | |
| +	case SCHED_IDLE:
 | |
| +		ret = 0;
 | |
| +		break;
 | |
| +	}
 | |
| +	return ret;
 | |
| +}
 | |
| +
 | |
| +/**
 | |
| + * sys_sched_get_priority_min - return minimum RT priority.
 | |
| + * @policy: scheduling class.
 | |
| + *
 | |
| + * this syscall returns the minimum rt_priority that can be used
 | |
| + * by a given scheduling class.
 | |
| + */
 | |
| +SYSCALL_DEFINE1(sched_get_priority_min, int, policy)
 | |
| +{
 | |
| +	int ret = -EINVAL;
 | |
| +
 | |
| +	switch (policy) {
 | |
| +	case SCHED_FIFO:
 | |
| +	case SCHED_RR:
 | |
| +		ret = 1;
 | |
| +		break;
 | |
| +	case SCHED_NORMAL:
 | |
| +	case SCHED_BATCH:
 | |
| +	case SCHED_ISO:
 | |
| +	case SCHED_IDLE:
 | |
| +		ret = 0;
 | |
| +		break;
 | |
| +	}
 | |
| +	return ret;
 | |
| +}
 | |
| +
 | |
| +/**
 | |
| + * sys_sched_rr_get_interval - return the default timeslice of a process.
 | |
| + * @pid: pid of the process.
 | |
| + * @interval: userspace pointer to the timeslice value.
 | |
| + *
 | |
| + * this syscall writes the default timeslice value of a given process
 | |
| + * into the user-space timespec buffer. A value of '0' means infinity.
 | |
| + */
 | |
| +SYSCALL_DEFINE2(sched_rr_get_interval, pid_t, pid,
 | |
| +		struct timespec __user *, interval)
 | |
| +{
 | |
| +	struct task_struct *p;
 | |
| +	int retval = -EINVAL;
 | |
| +	struct timespec t;
 | |
| +
 | |
| +	if (pid < 0)
 | |
| +		goto out_nounlock;
 | |
| +
 | |
| +	retval = -ESRCH;
 | |
| +	read_lock(&tasklist_lock);
 | |
| +	p = find_process_by_pid(pid);
 | |
| +	if (!p)
 | |
| +		goto out_unlock;
 | |
| +
 | |
| +	retval = security_task_getscheduler(p);
 | |
| +	if (retval)
 | |
| +		goto out_unlock;
 | |
| +
 | |
| +	t = ns_to_timespec(p->policy == SCHED_FIFO ? 0 :
 | |
| +			   MS_TO_NS(task_timeslice(p)));
 | |
| +	read_unlock(&tasklist_lock);
 | |
| +	retval = copy_to_user(interval, &t, sizeof(t)) ? -EFAULT : 0;
 | |
| +out_nounlock:
 | |
| +	return retval;
 | |
| +out_unlock:
 | |
| +	read_unlock(&tasklist_lock);
 | |
| +	return retval;
 | |
| +}
 | |
| +
 | |
| +static const char stat_nam[] = TASK_STATE_TO_CHAR_STR;
 | |
| +
 | |
| +void sched_show_task(struct task_struct *p)
 | |
| +{
 | |
| +	unsigned long free = 0;
 | |
| +	unsigned state;
 | |
| +
 | |
| +	state = p->state ? __ffs(p->state) + 1 : 0;
 | |
| +	printk(KERN_INFO "%-13.13s %c", p->comm,
 | |
| +		state < sizeof(stat_nam) - 1 ? stat_nam[state] : '?');
 | |
| +#if BITS_PER_LONG == 32
 | |
| +	if (state == TASK_RUNNING)
 | |
| +		printk(KERN_CONT " running  ");
 | |
| +	else
 | |
| +		printk(KERN_CONT " %08lx ", thread_saved_pc(p));
 | |
| +#else
 | |
| +	if (state == TASK_RUNNING)
 | |
| +		printk(KERN_CONT "  running task    ");
 | |
| +	else
 | |
| +		printk(KERN_CONT " %016lx ", thread_saved_pc(p));
 | |
| +#endif
 | |
| +#ifdef CONFIG_DEBUG_STACK_USAGE
 | |
| +	free = stack_not_used(p);
 | |
| +#endif
 | |
| +	printk(KERN_CONT "%5lu %5d %6d 0x%08lx\n", free,
 | |
| +		task_pid_nr(p), task_pid_nr(p->real_parent),
 | |
| +		(unsigned long)task_thread_info(p)->flags);
 | |
| +
 | |
| +	show_stack(p, NULL);
 | |
| +}
 | |
| +
 | |
| +void show_state_filter(unsigned long state_filter)
 | |
| +{
 | |
| +	struct task_struct *g, *p;
 | |
| +
 | |
| +#if BITS_PER_LONG == 32
 | |
| +	printk(KERN_INFO
 | |
| +		"  task                PC stack   pid father\n");
 | |
| +#else
 | |
| +	printk(KERN_INFO
 | |
| +		"  task                        PC stack   pid father\n");
 | |
| +#endif
 | |
| +	read_lock(&tasklist_lock);
 | |
| +	do_each_thread(g, p) {
 | |
| +		/*
 | |
| +		 * reset the NMI-timeout, listing all files on a slow
 | |
| +		 * console might take alot of time:
 | |
| +		 */
 | |
| +		touch_nmi_watchdog();
 | |
| +		if (!state_filter || (p->state & state_filter))
 | |
| +			sched_show_task(p);
 | |
| +	} while_each_thread(g, p);
 | |
| +
 | |
| +	touch_all_softlockup_watchdogs();
 | |
| +
 | |
| +	read_unlock(&tasklist_lock);
 | |
| +	/*
 | |
| +	 * Only show locks if all tasks are dumped:
 | |
| +	 */
 | |
| +	if (state_filter == -1)
 | |
| +		debug_show_all_locks();
 | |
| +}
 | |
| +
 | |
| +/**
 | |
| + * init_idle - set up an idle thread for a given CPU
 | |
| + * @idle: task in question
 | |
| + * @cpu: cpu the idle task belongs to
 | |
| + *
 | |
| + * NOTE: this function does not set the idle thread's NEED_RESCHED
 | |
| + * flag, to make booting more robust.
 | |
| + */
 | |
| +void __cpuinit init_idle(struct task_struct *idle, int cpu)
 | |
| +{
 | |
| +	struct rq *rq = cpu_rq(cpu);
 | |
| +	unsigned long flags;
 | |
| +
 | |
| +	time_grq_lock(rq, &flags);
 | |
| +	idle->timestamp = idle->last_ran = rq->clock;
 | |
| +	idle->state = TASK_RUNNING;
 | |
| +	/* Setting prio to illegal value shouldn't matter when never queued */
 | |
| +	idle->prio = rq->rq_prio = PRIO_LIMIT;
 | |
| +	rq->rq_deadline = idle->deadline;
 | |
| +	rq->rq_policy = idle->policy;
 | |
| +	rq->rq_time_slice = idle->rt.time_slice;
 | |
| +	idle->cpus_allowed = cpumask_of_cpu(cpu);
 | |
| +	set_task_cpu(idle, cpu);
 | |
| +	rq->curr = rq->idle = idle;
 | |
| +	idle->oncpu = 1;
 | |
| +	set_cpuidle_map(cpu);
 | |
| +#ifdef CONFIG_HOTPLUG_CPU
 | |
| +	idle->unplugged_mask = CPU_MASK_NONE;
 | |
| +#endif
 | |
| +	grq_unlock_irqrestore(&flags);
 | |
| +
 | |
| +	/* Set the preempt count _outside_ the spinlocks! */
 | |
| +#if defined(CONFIG_PREEMPT) && !defined(CONFIG_PREEMPT_BKL)
 | |
| +	task_thread_info(idle)->preempt_count = (idle->lock_depth >= 0);
 | |
| +#else
 | |
| +	task_thread_info(idle)->preempt_count = 0;
 | |
| +#endif
 | |
| +	ftrace_graph_init_task(idle);
 | |
| +}
 | |
| +
 | |
| +/*
 | |
| + * In a system that switches off the HZ timer nohz_cpu_mask
 | |
| + * indicates which cpus entered this state. This is used
 | |
| + * in the rcu update to wait only for active cpus. For system
 | |
| + * which do not switch off the HZ timer nohz_cpu_mask should
 | |
| + * always be CPU_BITS_NONE.
 | |
| + */
 | |
| +cpumask_var_t nohz_cpu_mask;
 | |
| +
 | |
| +#ifdef CONFIG_SMP
 | |
| +#ifdef CONFIG_NO_HZ
 | |
| +static struct {
 | |
| +	atomic_t load_balancer;
 | |
| +	cpumask_var_t cpu_mask;
 | |
| +	cpumask_var_t ilb_grp_nohz_mask;
 | |
| +} nohz ____cacheline_aligned = {
 | |
| +	.load_balancer = ATOMIC_INIT(-1),
 | |
| +};
 | |
| +
 | |
| +int get_nohz_load_balancer(void)
 | |
| +{
 | |
| +	return atomic_read(&nohz.load_balancer);
 | |
| +}
 | |
| +
 | |
| +/*
 | |
| + * This routine will try to nominate the ilb (idle load balancing)
 | |
| + * owner among the cpus whose ticks are stopped. ilb owner will do the idle
 | |
| + * load balancing on behalf of all those cpus. If all the cpus in the system
 | |
| + * go into this tickless mode, then there will be no ilb owner (as there is
 | |
| + * no need for one) and all the cpus will sleep till the next wakeup event
 | |
| + * arrives...
 | |
| + *
 | |
| + * For the ilb owner, tick is not stopped. And this tick will be used
 | |
| + * for idle load balancing. ilb owner will still be part of
 | |
| + * nohz.cpu_mask..
 | |
| + *
 | |
| + * While stopping the tick, this cpu will become the ilb owner if there
 | |
| + * is no other owner. And will be the owner till that cpu becomes busy
 | |
| + * or if all cpus in the system stop their ticks at which point
 | |
| + * there is no need for ilb owner.
 | |
| + *
 | |
| + * When the ilb owner becomes busy, it nominates another owner, during the
 | |
| + * next busy scheduler_tick()
 | |
| + */
 | |
| +int select_nohz_load_balancer(int stop_tick)
 | |
| +{
 | |
| +	int cpu = smp_processor_id();
 | |
| +
 | |
| +	if (stop_tick) {
 | |
| +		cpu_rq(cpu)->in_nohz_recently = 1;
 | |
| +
 | |
| +		if (!cpu_active(cpu)) {
 | |
| +			if (atomic_read(&nohz.load_balancer) != cpu)
 | |
| +				return 0;
 | |
| +
 | |
| +			/*
 | |
| +			 * If we are going offline and still the leader,
 | |
| +			 * give up!
 | |
| +			 */
 | |
| +			if (atomic_cmpxchg(&nohz.load_balancer, cpu, -1) != cpu)
 | |
| +				BUG();
 | |
| +
 | |
| +			return 0;
 | |
| +		}
 | |
| +
 | |
| +		cpumask_set_cpu(cpu, nohz.cpu_mask);
 | |
| +
 | |
| +		/* time for ilb owner also to sleep */
 | |
| +		if (cpumask_weight(nohz.cpu_mask) == num_online_cpus()) {
 | |
| +			if (atomic_read(&nohz.load_balancer) == cpu)
 | |
| +				atomic_set(&nohz.load_balancer, -1);
 | |
| +			return 0;
 | |
| +		}
 | |
| +
 | |
| +		if (atomic_read(&nohz.load_balancer) == -1) {
 | |
| +			/* make me the ilb owner */
 | |
| +			if (atomic_cmpxchg(&nohz.load_balancer, -1, cpu) == -1)
 | |
| +				return 1;
 | |
| +		} else if (atomic_read(&nohz.load_balancer) == cpu)
 | |
| +			return 1;
 | |
| +	} else {
 | |
| +		if (!cpumask_test_cpu(cpu, nohz.cpu_mask))
 | |
| +			return 0;
 | |
| +
 | |
| +		cpumask_clear_cpu(cpu, nohz.cpu_mask);
 | |
| +
 | |
| +		if (atomic_read(&nohz.load_balancer) == cpu)
 | |
| +			if (atomic_cmpxchg(&nohz.load_balancer, cpu, -1) != cpu)
 | |
| +				BUG();
 | |
| +	}
 | |
| +	return 0;
 | |
| +}
 | |
| +
 | |
| +/*
 | |
| + * When add_timer_on() enqueues a timer into the timer wheel of an
 | |
| + * idle CPU then this timer might expire before the next timer event
 | |
| + * which is scheduled to wake up that CPU. In case of a completely
 | |
| + * idle system the next event might even be infinite time into the
 | |
| + * future. wake_up_idle_cpu() ensures that the CPU is woken up and
 | |
| + * leaves the inner idle loop so the newly added timer is taken into
 | |
| + * account when the CPU goes back to idle and evaluates the timer
 | |
| + * wheel for the next timer event.
 | |
| + */
 | |
| +void wake_up_idle_cpu(int cpu)
 | |
| +{
 | |
| +	struct task_struct *idle;
 | |
| +	struct rq *rq;
 | |
| +
 | |
| +	if (cpu == smp_processor_id())
 | |
| +		return;
 | |
| +
 | |
| +	rq = cpu_rq(cpu);
 | |
| +	idle = rq->idle;
 | |
| +
 | |
| +	/*
 | |
| +	 * This is safe, as this function is called with the timer
 | |
| +	 * wheel base lock of (cpu) held. When the CPU is on the way
 | |
| +	 * to idle and has not yet set rq->curr to idle then it will
 | |
| +	 * be serialized on the timer wheel base lock and take the new
 | |
| +	 * timer into account automatically.
 | |
| +	 */
 | |
| +	if (unlikely(rq->curr != idle))
 | |
| +		return;
 | |
| +
 | |
| +	/*
 | |
| +	 * We can set TIF_RESCHED on the idle task of the other CPU
 | |
| +	 * lockless. The worst case is that the other CPU runs the
 | |
| +	 * idle task through an additional NOOP schedule()
 | |
| +	 */
 | |
| +	set_tsk_need_resched(idle);
 | |
| +
 | |
| +	/* NEED_RESCHED must be visible before we test polling */
 | |
| +	smp_mb();
 | |
| +	if (!tsk_is_polling(idle))
 | |
| +		smp_send_reschedule(cpu);
 | |
| +}
 | |
| +
 | |
| +#endif /* CONFIG_NO_HZ */
 | |
| +
 | |
| +/*
 | |
| + * Change a given task's CPU affinity. Migrate the thread to a
 | |
| + * proper CPU and schedule it away if the CPU it's executing on
 | |
| + * is removed from the allowed bitmask.
 | |
| + *
 | |
| + * NOTE: the caller must have a valid reference to the task, the
 | |
| + * task must not exit() & deallocate itself prematurely. The
 | |
| + * call is not atomic; no spinlocks may be held.
 | |
| + */
 | |
| +int set_cpus_allowed_ptr(struct task_struct *p, const struct cpumask *new_mask)
 | |
| +{
 | |
| +	unsigned long flags;
 | |
| +	int running = 0;
 | |
| +	int queued = 0;
 | |
| +	struct rq *rq;
 | |
| +	int ret = 0;
 | |
| +
 | |
| +	rq = task_grq_lock(p, &flags);
 | |
| +	if (!cpumask_intersects(new_mask, cpu_online_mask)) {
 | |
| +		ret = -EINVAL;
 | |
| +		goto out;
 | |
| +	}
 | |
| +
 | |
| +	if (unlikely((p->flags & PF_THREAD_BOUND) && p != current &&
 | |
| +		     !cpumask_equal(&p->cpus_allowed, new_mask))) {
 | |
| +		ret = -EINVAL;
 | |
| +		goto out;
 | |
| +	}
 | |
| +
 | |
| +	queued = task_queued_only(p);
 | |
| +
 | |
| +	cpumask_copy(&p->cpus_allowed, new_mask);
 | |
| +	p->rt.nr_cpus_allowed = cpumask_weight(new_mask);
 | |
| +
 | |
| +	/* Can the task run on the task's current CPU? If so, we're done */
 | |
| +	if (cpumask_test_cpu(task_cpu(p), new_mask))
 | |
| +		goto out;
 | |
| +
 | |
| +	/* Reschedule the task, schedule() will know if it can keep running */
 | |
| +	if (task_running(p))
 | |
| +		running = 1;
 | |
| +	else
 | |
| +		set_task_cpu(p, cpumask_any_and(cpu_online_mask, new_mask));
 | |
| +
 | |
| +out:
 | |
| +	if (queued)
 | |
| +		try_preempt(p);
 | |
| +	task_grq_unlock(&flags);
 | |
| +
 | |
| +	/* This might be a flaky way of changing cpus! */
 | |
| +	if (running)
 | |
| +		schedule();
 | |
| +	return ret;
 | |
| +}
 | |
| +EXPORT_SYMBOL_GPL(set_cpus_allowed_ptr);
 | |
| +
 | |
| +#ifdef CONFIG_HOTPLUG_CPU
 | |
| +/* Schedules idle task to be the next runnable task on current CPU.
 | |
| + * It does so by boosting its priority to highest possible.
 | |
| + * Used by CPU offline code.
 | |
| + */
 | |
| +void sched_idle_next(void)
 | |
| +{
 | |
| +	int this_cpu = smp_processor_id();
 | |
| +	struct rq *rq = cpu_rq(this_cpu);
 | |
| +	struct task_struct *idle = rq->idle;
 | |
| +	unsigned long flags;
 | |
| +
 | |
| +	/* cpu has to be offline */
 | |
| +	BUG_ON(cpu_online(this_cpu));
 | |
| +
 | |
| +	/*
 | |
| +	 * Strictly not necessary since rest of the CPUs are stopped by now
 | |
| +	 * and interrupts disabled on the current cpu.
 | |
| +	 */
 | |
| +	time_grq_lock(rq, &flags);
 | |
| +
 | |
| +	__setscheduler(idle, SCHED_FIFO, MAX_RT_PRIO - 1);
 | |
| +
 | |
| +	activate_idle_task(idle);
 | |
| +	set_tsk_need_resched(rq->curr);
 | |
| +
 | |
| +	grq_unlock_irqrestore(&flags);
 | |
| +}
 | |
| +
 | |
| +/*
 | |
| + * Ensures that the idle task is using init_mm right before its cpu goes
 | |
| + * offline.
 | |
| + */
 | |
| +void idle_task_exit(void)
 | |
| +{
 | |
| +	struct mm_struct *mm = current->active_mm;
 | |
| +
 | |
| +	BUG_ON(cpu_online(smp_processor_id()));
 | |
| +
 | |
| +	if (mm != &init_mm)
 | |
| +		switch_mm(mm, &init_mm, current);
 | |
| +	mmdrop(mm);
 | |
| +}
 | |
| +
 | |
| +#endif /* CONFIG_HOTPLUG_CPU */
 | |
| +
 | |
| +#if defined(CONFIG_SCHED_DEBUG) && defined(CONFIG_SYSCTL)
 | |
| +
 | |
| +static struct ctl_table sd_ctl_dir[] = {
 | |
| +	{
 | |
| +		.procname	= "sched_domain",
 | |
| +		.mode		= 0555,
 | |
| +	},
 | |
| +	{0, },
 | |
| +};
 | |
| +
 | |
| +static struct ctl_table sd_ctl_root[] = {
 | |
| +	{
 | |
| +		.ctl_name	= CTL_KERN,
 | |
| +		.procname	= "kernel",
 | |
| +		.mode		= 0555,
 | |
| +		.child		= sd_ctl_dir,
 | |
| +	},
 | |
| +	{0, },
 | |
| +};
 | |
| +
 | |
| +static struct ctl_table *sd_alloc_ctl_entry(int n)
 | |
| +{
 | |
| +	struct ctl_table *entry =
 | |
| +		kcalloc(n, sizeof(struct ctl_table), GFP_KERNEL);
 | |
| +
 | |
| +	return entry;
 | |
| +}
 | |
| +
 | |
| +static void sd_free_ctl_entry(struct ctl_table **tablep)
 | |
| +{
 | |
| +	struct ctl_table *entry;
 | |
| +
 | |
| +	/*
 | |
| +	 * In the intermediate directories, both the child directory and
 | |
| +	 * procname are dynamically allocated and could fail but the mode
 | |
| +	 * will always be set. In the lowest directory the names are
 | |
| +	 * static strings and all have proc handlers.
 | |
| +	 */
 | |
| +	for (entry = *tablep; entry->mode; entry++) {
 | |
| +		if (entry->child)
 | |
| +			sd_free_ctl_entry(&entry->child);
 | |
| +		if (entry->proc_handler == NULL)
 | |
| +			kfree(entry->procname);
 | |
| +	}
 | |
| +
 | |
| +	kfree(*tablep);
 | |
| +	*tablep = NULL;
 | |
| +}
 | |
| +
 | |
| +static void
 | |
| +set_table_entry(struct ctl_table *entry,
 | |
| +		const char *procname, void *data, int maxlen,
 | |
| +		mode_t mode, proc_handler *proc_handler)
 | |
| +{
 | |
| +	entry->procname = procname;
 | |
| +	entry->data = data;
 | |
| +	entry->maxlen = maxlen;
 | |
| +	entry->mode = mode;
 | |
| +	entry->proc_handler = proc_handler;
 | |
| +}
 | |
| +
 | |
| +static struct ctl_table *
 | |
| +sd_alloc_ctl_domain_table(struct sched_domain *sd)
 | |
| +{
 | |
| +	struct ctl_table *table = sd_alloc_ctl_entry(13);
 | |
| +
 | |
| +	if (table == NULL)
 | |
| +		return NULL;
 | |
| +
 | |
| +	set_table_entry(&table[0], "min_interval", &sd->min_interval,
 | |
| +		sizeof(long), 0644, proc_doulongvec_minmax);
 | |
| +	set_table_entry(&table[1], "max_interval", &sd->max_interval,
 | |
| +		sizeof(long), 0644, proc_doulongvec_minmax);
 | |
| +	set_table_entry(&table[2], "busy_idx", &sd->busy_idx,
 | |
| +		sizeof(int), 0644, proc_dointvec_minmax);
 | |
| +	set_table_entry(&table[3], "idle_idx", &sd->idle_idx,
 | |
| +		sizeof(int), 0644, proc_dointvec_minmax);
 | |
| +	set_table_entry(&table[4], "newidle_idx", &sd->newidle_idx,
 | |
| +		sizeof(int), 0644, proc_dointvec_minmax);
 | |
| +	set_table_entry(&table[5], "wake_idx", &sd->wake_idx,
 | |
| +		sizeof(int), 0644, proc_dointvec_minmax);
 | |
| +	set_table_entry(&table[6], "forkexec_idx", &sd->forkexec_idx,
 | |
| +		sizeof(int), 0644, proc_dointvec_minmax);
 | |
| +	set_table_entry(&table[7], "busy_factor", &sd->busy_factor,
 | |
| +		sizeof(int), 0644, proc_dointvec_minmax);
 | |
| +	set_table_entry(&table[8], "imbalance_pct", &sd->imbalance_pct,
 | |
| +		sizeof(int), 0644, proc_dointvec_minmax);
 | |
| +	set_table_entry(&table[9], "cache_nice_tries",
 | |
| +		&sd->cache_nice_tries,
 | |
| +		sizeof(int), 0644, proc_dointvec_minmax);
 | |
| +	set_table_entry(&table[10], "flags", &sd->flags,
 | |
| +		sizeof(int), 0644, proc_dointvec_minmax);
 | |
| +	set_table_entry(&table[11], "name", sd->name,
 | |
| +		CORENAME_MAX_SIZE, 0444, proc_dostring);
 | |
| +	/* &table[12] is terminator */
 | |
| +
 | |
| +	return table;
 | |
| +}
 | |
| +
 | |
| +static ctl_table *sd_alloc_ctl_cpu_table(int cpu)
 | |
| +{
 | |
| +	struct ctl_table *entry, *table;
 | |
| +	struct sched_domain *sd;
 | |
| +	int domain_num = 0, i;
 | |
| +	char buf[32];
 | |
| +
 | |
| +	for_each_domain(cpu, sd)
 | |
| +		domain_num++;
 | |
| +	entry = table = sd_alloc_ctl_entry(domain_num + 1);
 | |
| +	if (table == NULL)
 | |
| +		return NULL;
 | |
| +
 | |
| +	i = 0;
 | |
| +	for_each_domain(cpu, sd) {
 | |
| +		snprintf(buf, 32, "domain%d", i);
 | |
| +		entry->procname = kstrdup(buf, GFP_KERNEL);
 | |
| +		entry->mode = 0555;
 | |
| +		entry->child = sd_alloc_ctl_domain_table(sd);
 | |
| +		entry++;
 | |
| +		i++;
 | |
| +	}
 | |
| +	return table;
 | |
| +}
 | |
| +
 | |
| +static struct ctl_table_header *sd_sysctl_header;
 | |
| +static void register_sched_domain_sysctl(void)
 | |
| +{
 | |
| +	int i, cpu_num = num_online_cpus();
 | |
| +	struct ctl_table *entry = sd_alloc_ctl_entry(cpu_num + 1);
 | |
| +	char buf[32];
 | |
| +
 | |
| +	WARN_ON(sd_ctl_dir[0].child);
 | |
| +	sd_ctl_dir[0].child = entry;
 | |
| +
 | |
| +	if (entry == NULL)
 | |
| +		return;
 | |
| +
 | |
| +	for_each_online_cpu(i) {
 | |
| +		snprintf(buf, 32, "cpu%d", i);
 | |
| +		entry->procname = kstrdup(buf, GFP_KERNEL);
 | |
| +		entry->mode = 0555;
 | |
| +		entry->child = sd_alloc_ctl_cpu_table(i);
 | |
| +		entry++;
 | |
| +	}
 | |
| +
 | |
| +	WARN_ON(sd_sysctl_header);
 | |
| +	sd_sysctl_header = register_sysctl_table(sd_ctl_root);
 | |
| +}
 | |
| +
 | |
| +/* may be called multiple times per register */
 | |
| +static void unregister_sched_domain_sysctl(void)
 | |
| +{
 | |
| +	if (sd_sysctl_header)
 | |
| +		unregister_sysctl_table(sd_sysctl_header);
 | |
| +	sd_sysctl_header = NULL;
 | |
| +	if (sd_ctl_dir[0].child)
 | |
| +		sd_free_ctl_entry(&sd_ctl_dir[0].child);
 | |
| +}
 | |
| +#else
 | |
| +static void register_sched_domain_sysctl(void)
 | |
| +{
 | |
| +}
 | |
| +static void unregister_sched_domain_sysctl(void)
 | |
| +{
 | |
| +}
 | |
| +#endif
 | |
| +
 | |
| +static void set_rq_online(struct rq *rq)
 | |
| +{
 | |
| +	if (!rq->online) {
 | |
| +		cpumask_set_cpu(rq->cpu, rq->rd->online);
 | |
| +		rq->online = 1;
 | |
| +	}
 | |
| +}
 | |
| +
 | |
| +static void set_rq_offline(struct rq *rq)
 | |
| +{
 | |
| +	if (rq->online) {
 | |
| +		cpumask_clear_cpu(rq->cpu, rq->rd->online);
 | |
| +		rq->online = 0;
 | |
| +	}
 | |
| +}
 | |
| +
 | |
| +#ifdef CONFIG_HOTPLUG_CPU
 | |
| +/*
 | |
| + * This cpu is going down, so walk over the tasklist and find tasks that can
 | |
| + * only run on this cpu and remove their affinity. Store their value in
 | |
| + * unplugged_mask so it can be restored once their correct cpu is online. No
 | |
| + * need to do anything special since they'll just move on next reschedule if
 | |
| + * they're running.
 | |
| + */
 | |
| +static void remove_cpu(unsigned long cpu)
 | |
| +{
 | |
| +	struct task_struct *p, *t;
 | |
| +
 | |
| +	read_lock(&tasklist_lock);
 | |
| +
 | |
| +	do_each_thread(t, p) {
 | |
| +		cpumask_t cpus_remaining;
 | |
| +
 | |
| +		cpus_and(cpus_remaining, p->cpus_allowed, cpu_online_map);
 | |
| +		cpu_clear(cpu, cpus_remaining);
 | |
| +		if (cpus_empty(cpus_remaining)) {
 | |
| +			p->unplugged_mask = p->cpus_allowed;
 | |
| +			p->cpus_allowed = cpu_possible_map;
 | |
| +		}
 | |
| +	} while_each_thread(t, p);
 | |
| +
 | |
| +	read_unlock(&tasklist_lock);
 | |
| +}
 | |
| +
 | |
| +/*
 | |
| + * This cpu is coming up so add it to the cpus_allowed.
 | |
| + */
 | |
| +static void add_cpu(unsigned long cpu)
 | |
| +{
 | |
| +	struct task_struct *p, *t;
 | |
| +
 | |
| +	read_lock(&tasklist_lock);
 | |
| +
 | |
| +	do_each_thread(t, p) {
 | |
| +		/* Have we taken all the cpus from the unplugged_mask back */
 | |
| +		if (cpus_empty(p->unplugged_mask))
 | |
| +			continue;
 | |
| +
 | |
| +		/* Was this cpu in the unplugged_mask mask */
 | |
| +		if (cpu_isset(cpu, p->unplugged_mask)) {
 | |
| +			cpu_set(cpu, p->cpus_allowed);
 | |
| +			if (cpus_subset(p->unplugged_mask, p->cpus_allowed)) {
 | |
| +				/*
 | |
| +				 * Have we set more than the unplugged_mask?
 | |
| +				 * If so, that means we have remnants set from
 | |
| +				 * the unplug/plug cycle and need to remove
 | |
| +				 * them. Then clear the unplugged_mask as we've
 | |
| +				 * set all the cpus back.
 | |
| +				 */
 | |
| +				p->cpus_allowed = p->unplugged_mask;
 | |
| +				cpus_clear(p->unplugged_mask);
 | |
| +			}
 | |
| +		}
 | |
| +	} while_each_thread(t, p);
 | |
| +
 | |
| +	read_unlock(&tasklist_lock);
 | |
| +}
 | |
| +#else
 | |
| +static void add_cpu(unsigned long cpu)
 | |
| +{
 | |
| +}
 | |
| +#endif
 | |
| +
 | |
| +/*
 | |
| + * migration_call - callback that gets triggered when a CPU is added.
 | |
| + */
 | |
| +static int __cpuinit
 | |
| +migration_call(struct notifier_block *nfb, unsigned long action, void *hcpu)
 | |
| +{
 | |
| +	int cpu = (long)hcpu;
 | |
| +	unsigned long flags;
 | |
| +	struct rq *rq;
 | |
| +
 | |
| +	switch (action) {
 | |
| +
 | |
| +	case CPU_UP_PREPARE:
 | |
| +	case CPU_UP_PREPARE_FROZEN:
 | |
| +		break;
 | |
| +
 | |
| +	case CPU_ONLINE:
 | |
| +	case CPU_ONLINE_FROZEN:
 | |
| +		/* Update our root-domain */
 | |
| +		rq = cpu_rq(cpu);
 | |
| +		grq_lock_irqsave(&flags);
 | |
| +		if (rq->rd) {
 | |
| +			BUG_ON(!cpumask_test_cpu(cpu, rq->rd->span));
 | |
| +
 | |
| +			set_rq_online(rq);
 | |
| +		}
 | |
| +		add_cpu(cpu);
 | |
| +		grq_unlock_irqrestore(&flags);
 | |
| +		break;
 | |
| +
 | |
| +#ifdef CONFIG_HOTPLUG_CPU
 | |
| +	case CPU_UP_CANCELED:
 | |
| +	case CPU_UP_CANCELED_FROZEN:
 | |
| +		break;
 | |
| +
 | |
| +	case CPU_DEAD:
 | |
| +	case CPU_DEAD_FROZEN:
 | |
| +		cpuset_lock(); /* around calls to cpuset_cpus_allowed_lock() */
 | |
| +		rq = cpu_rq(cpu);
 | |
| +		/* Idle task back to normal (off runqueue, low prio) */
 | |
| +		grq_lock_irq();
 | |
| +		remove_cpu(cpu);
 | |
| +		deactivate_task(rq->idle);
 | |
| +		rq->idle->static_prio = MAX_PRIO;
 | |
| +		__setscheduler(rq->idle, SCHED_NORMAL, 0);
 | |
| +		rq->idle->prio = PRIO_LIMIT;
 | |
| +		update_rq_clock(rq);
 | |
| +		grq_unlock_irq();
 | |
| +		cpuset_unlock();
 | |
| +		break;
 | |
| +
 | |
| +	case CPU_DYING:
 | |
| +	case CPU_DYING_FROZEN:
 | |
| +		rq = cpu_rq(cpu);
 | |
| +		grq_lock_irqsave(&flags);
 | |
| +		if (rq->rd) {
 | |
| +			BUG_ON(!cpumask_test_cpu(cpu, rq->rd->span));
 | |
| +			set_rq_offline(rq);
 | |
| +		}
 | |
| +		grq_unlock_irqrestore(&flags);
 | |
| +		break;
 | |
| +#endif
 | |
| +	}
 | |
| +	return NOTIFY_OK;
 | |
| +}
 | |
| +
 | |
| +/*
 | |
| + * Register at high priority so that task migration (migrate_all_tasks)
 | |
| + * happens before everything else.  This has to be lower priority than
 | |
| + * the notifier in the perf_counter subsystem, though.
 | |
| + */
 | |
| +static struct notifier_block __cpuinitdata migration_notifier = {
 | |
| +	.notifier_call = migration_call,
 | |
| +	.priority = 10
 | |
| +};
 | |
| +
 | |
| +int __init migration_init(void)
 | |
| +{
 | |
| +	void *cpu = (void *)(long)smp_processor_id();
 | |
| +	int err;
 | |
| +
 | |
| +	/* Start one for the boot CPU: */
 | |
| +	err = migration_call(&migration_notifier, CPU_UP_PREPARE, cpu);
 | |
| +	BUG_ON(err == NOTIFY_BAD);
 | |
| +	migration_call(&migration_notifier, CPU_ONLINE, cpu);
 | |
| +	register_cpu_notifier(&migration_notifier);
 | |
| +
 | |
| +	return 0;
 | |
| +}
 | |
| +early_initcall(migration_init);
 | |
| +#endif
 | |
| +
 | |
| +/*
 | |
| + * sched_domains_mutex serializes calls to arch_init_sched_domains,
 | |
| + * detach_destroy_domains and partition_sched_domains.
 | |
| + */
 | |
| +static DEFINE_MUTEX(sched_domains_mutex);
 | |
| +
 | |
| +#ifdef CONFIG_SMP
 | |
| +
 | |
| +#ifdef CONFIG_SCHED_DEBUG
 | |
| +
 | |
| +static int sched_domain_debug_one(struct sched_domain *sd, int cpu, int level,
 | |
| +				  struct cpumask *groupmask)
 | |
| +{
 | |
| +	struct sched_group *group = sd->groups;
 | |
| +	char str[256];
 | |
| +
 | |
| +	cpulist_scnprintf(str, sizeof(str), sched_domain_span(sd));
 | |
| +	cpumask_clear(groupmask);
 | |
| +
 | |
| +	printk(KERN_DEBUG "%*s domain %d: ", level, "", level);
 | |
| +
 | |
| +	if (!(sd->flags & SD_LOAD_BALANCE)) {
 | |
| +		printk("does not load-balance\n");
 | |
| +		if (sd->parent)
 | |
| +			printk(KERN_ERR "ERROR: !SD_LOAD_BALANCE domain"
 | |
| +					" has parent");
 | |
| +		return -1;
 | |
| +	}
 | |
| +
 | |
| +	printk(KERN_CONT "span %s level %s\n", str, sd->name);
 | |
| +
 | |
| +	if (!cpumask_test_cpu(cpu, sched_domain_span(sd))) {
 | |
| +		printk(KERN_ERR "ERROR: domain->span does not contain "
 | |
| +				"CPU%d\n", cpu);
 | |
| +	}
 | |
| +	if (!cpumask_test_cpu(cpu, sched_group_cpus(group))) {
 | |
| +		printk(KERN_ERR "ERROR: domain->groups does not contain"
 | |
| +				" CPU%d\n", cpu);
 | |
| +	}
 | |
| +
 | |
| +	printk(KERN_DEBUG "%*s groups:", level + 1, "");
 | |
| +	do {
 | |
| +		if (!group) {
 | |
| +			printk("\n");
 | |
| +			printk(KERN_ERR "ERROR: group is NULL\n");
 | |
| +			break;
 | |
| +		}
 | |
| +
 | |
| +		if (!group->__cpu_power) {
 | |
| +			printk(KERN_CONT "\n");
 | |
| +			printk(KERN_ERR "ERROR: domain->cpu_power not "
 | |
| +					"set\n");
 | |
| +			break;
 | |
| +		}
 | |
| +
 | |
| +		if (!cpumask_weight(sched_group_cpus(group))) {
 | |
| +			printk(KERN_CONT "\n");
 | |
| +			printk(KERN_ERR "ERROR: empty group\n");
 | |
| +			break;
 | |
| +		}
 | |
| +
 | |
| +		if (cpumask_intersects(groupmask, sched_group_cpus(group))) {
 | |
| +			printk(KERN_CONT "\n");
 | |
| +			printk(KERN_ERR "ERROR: repeated CPUs\n");
 | |
| +			break;
 | |
| +		}
 | |
| +
 | |
| +		cpumask_or(groupmask, groupmask, sched_group_cpus(group));
 | |
| +
 | |
| +		cpulist_scnprintf(str, sizeof(str), sched_group_cpus(group));
 | |
| +
 | |
| +		printk(KERN_CONT " %s", str);
 | |
| +		if (group->__cpu_power != SCHED_LOAD_SCALE) {
 | |
| +			printk(KERN_CONT " (__cpu_power = %d)",
 | |
| +				group->__cpu_power);
 | |
| +		}
 | |
| +
 | |
| +		group = group->next;
 | |
| +	} while (group != sd->groups);
 | |
| +	printk(KERN_CONT "\n");
 | |
| +
 | |
| +	if (!cpumask_equal(sched_domain_span(sd), groupmask))
 | |
| +		printk(KERN_ERR "ERROR: groups don't span domain->span\n");
 | |
| +
 | |
| +	if (sd->parent &&
 | |
| +	    !cpumask_subset(groupmask, sched_domain_span(sd->parent)))
 | |
| +		printk(KERN_ERR "ERROR: parent span is not a superset "
 | |
| +			"of domain->span\n");
 | |
| +	return 0;
 | |
| +}
 | |
| +
 | |
| +static void sched_domain_debug(struct sched_domain *sd, int cpu)
 | |
| +{
 | |
| +	cpumask_var_t groupmask;
 | |
| +	int level = 0;
 | |
| +
 | |
| +	if (!sd) {
 | |
| +		printk(KERN_DEBUG "CPU%d attaching NULL sched-domain.\n", cpu);
 | |
| +		return;
 | |
| +	}
 | |
| +
 | |
| +	printk(KERN_DEBUG "CPU%d attaching sched-domain:\n", cpu);
 | |
| +
 | |
| +	if (!alloc_cpumask_var(&groupmask, GFP_KERNEL)) {
 | |
| +		printk(KERN_DEBUG "Cannot load-balance (out of memory)\n");
 | |
| +		return;
 | |
| +	}
 | |
| +
 | |
| +	for (;;) {
 | |
| +		if (sched_domain_debug_one(sd, cpu, level, groupmask))
 | |
| +			break;
 | |
| +		level++;
 | |
| +		sd = sd->parent;
 | |
| +		if (!sd)
 | |
| +			break;
 | |
| +	}
 | |
| +	free_cpumask_var(groupmask);
 | |
| +}
 | |
| +#else /* !CONFIG_SCHED_DEBUG */
 | |
| +# define sched_domain_debug(sd, cpu) do { } while (0)
 | |
| +#endif /* CONFIG_SCHED_DEBUG */
 | |
| +
 | |
| +static int sd_degenerate(struct sched_domain *sd)
 | |
| +{
 | |
| +	if (cpumask_weight(sched_domain_span(sd)) == 1)
 | |
| +		return 1;
 | |
| +
 | |
| +	/* Following flags need at least 2 groups */
 | |
| +	if (sd->flags & (SD_LOAD_BALANCE |
 | |
| +			 SD_BALANCE_NEWIDLE |
 | |
| +			 SD_BALANCE_FORK |
 | |
| +			 SD_BALANCE_EXEC |
 | |
| +			 SD_SHARE_CPUPOWER |
 | |
| +			 SD_SHARE_PKG_RESOURCES)) {
 | |
| +		if (sd->groups != sd->groups->next)
 | |
| +			return 0;
 | |
| +	}
 | |
| +
 | |
| +	/* Following flags don't use groups */
 | |
| +	if (sd->flags & (SD_WAKE_IDLE |
 | |
| +			 SD_WAKE_AFFINE |
 | |
| +			 SD_WAKE_BALANCE))
 | |
| +		return 0;
 | |
| +
 | |
| +	return 1;
 | |
| +}
 | |
| +
 | |
| +static int
 | |
| +sd_parent_degenerate(struct sched_domain *sd, struct sched_domain *parent)
 | |
| +{
 | |
| +	unsigned long cflags = sd->flags, pflags = parent->flags;
 | |
| +
 | |
| +	if (sd_degenerate(parent))
 | |
| +		return 1;
 | |
| +
 | |
| +	if (!cpumask_equal(sched_domain_span(sd), sched_domain_span(parent)))
 | |
| +		return 0;
 | |
| +
 | |
| +	/* Does parent contain flags not in child? */
 | |
| +	/* WAKE_BALANCE is a subset of WAKE_AFFINE */
 | |
| +	if (cflags & SD_WAKE_AFFINE)
 | |
| +		pflags &= ~SD_WAKE_BALANCE;
 | |
| +	/* Flags needing groups don't count if only 1 group in parent */
 | |
| +	if (parent->groups == parent->groups->next) {
 | |
| +		pflags &= ~(SD_LOAD_BALANCE |
 | |
| +				SD_BALANCE_NEWIDLE |
 | |
| +				SD_BALANCE_FORK |
 | |
| +				SD_BALANCE_EXEC |
 | |
| +				SD_SHARE_CPUPOWER |
 | |
| +				SD_SHARE_PKG_RESOURCES);
 | |
| +		if (nr_node_ids == 1)
 | |
| +			pflags &= ~SD_SERIALIZE;
 | |
| +	}
 | |
| +	if (~cflags & pflags)
 | |
| +		return 0;
 | |
| +
 | |
| +	return 1;
 | |
| +}
 | |
| +
 | |
| +static void free_rootdomain(struct root_domain *rd)
 | |
| +{
 | |
| +	free_cpumask_var(rd->rto_mask);
 | |
| +	free_cpumask_var(rd->online);
 | |
| +	free_cpumask_var(rd->span);
 | |
| +	kfree(rd);
 | |
| +}
 | |
| +
 | |
| +static void rq_attach_root(struct rq *rq, struct root_domain *rd)
 | |
| +{
 | |
| +	struct root_domain *old_rd = NULL;
 | |
| +	unsigned long flags;
 | |
| +
 | |
| +	grq_lock_irqsave(&flags);
 | |
| +
 | |
| +	if (rq->rd) {
 | |
| +		old_rd = rq->rd;
 | |
| +
 | |
| +		if (cpumask_test_cpu(rq->cpu, old_rd->online))
 | |
| +			set_rq_offline(rq);
 | |
| +
 | |
| +		cpumask_clear_cpu(rq->cpu, old_rd->span);
 | |
| +
 | |
| +		/*
 | |
| +		 * If we dont want to free the old_rt yet then
 | |
| +		 * set old_rd to NULL to skip the freeing later
 | |
| +		 * in this function:
 | |
| +		 */
 | |
| +		if (!atomic_dec_and_test(&old_rd->refcount))
 | |
| +			old_rd = NULL;
 | |
| +	}
 | |
| +
 | |
| +	atomic_inc(&rd->refcount);
 | |
| +	rq->rd = rd;
 | |
| +
 | |
| +	cpumask_set_cpu(rq->cpu, rd->span);
 | |
| +	if (cpumask_test_cpu(rq->cpu, cpu_online_mask))
 | |
| +		set_rq_online(rq);
 | |
| +
 | |
| +	grq_unlock_irqrestore(&flags);
 | |
| +
 | |
| +	if (old_rd)
 | |
| +		free_rootdomain(old_rd);
 | |
| +}
 | |
| +
 | |
| +static int init_rootdomain(struct root_domain *rd, bool bootmem)
 | |
| +{
 | |
| +	gfp_t gfp = GFP_KERNEL;
 | |
| +
 | |
| +	memset(rd, 0, sizeof(*rd));
 | |
| +
 | |
| +	if (bootmem)
 | |
| +		gfp = GFP_NOWAIT;
 | |
| +
 | |
| +	if (!alloc_cpumask_var(&rd->span, gfp))
 | |
| +		goto out;
 | |
| +	if (!alloc_cpumask_var(&rd->online, gfp))
 | |
| +		goto free_span;
 | |
| +	if (!alloc_cpumask_var(&rd->rto_mask, gfp))
 | |
| +		goto free_online;
 | |
| +
 | |
| +	return 0;
 | |
| +
 | |
| +free_online:
 | |
| +	free_cpumask_var(rd->online);
 | |
| +free_span:
 | |
| +	free_cpumask_var(rd->span);
 | |
| +out:
 | |
| +	return -ENOMEM;
 | |
| +}
 | |
| +
 | |
| +static void init_defrootdomain(void)
 | |
| +{
 | |
| +	init_rootdomain(&def_root_domain, true);
 | |
| +
 | |
| +	atomic_set(&def_root_domain.refcount, 1);
 | |
| +}
 | |
| +
 | |
| +static struct root_domain *alloc_rootdomain(void)
 | |
| +{
 | |
| +	struct root_domain *rd;
 | |
| +
 | |
| +	rd = kmalloc(sizeof(*rd), GFP_KERNEL);
 | |
| +	if (!rd)
 | |
| +		return NULL;
 | |
| +
 | |
| +	if (init_rootdomain(rd, false) != 0) {
 | |
| +		kfree(rd);
 | |
| +		return NULL;
 | |
| +	}
 | |
| +
 | |
| +	return rd;
 | |
| +}
 | |
| +
 | |
| +/*
 | |
| + * Attach the domain 'sd' to 'cpu' as its base domain. Callers must
 | |
| + * hold the hotplug lock.
 | |
| + */
 | |
| +static void
 | |
| +cpu_attach_domain(struct sched_domain *sd, struct root_domain *rd, int cpu)
 | |
| +{
 | |
| +	struct rq *rq = cpu_rq(cpu);
 | |
| +	struct sched_domain *tmp;
 | |
| +
 | |
| +	/* Remove the sched domains which do not contribute to scheduling. */
 | |
| +	for (tmp = sd; tmp; ) {
 | |
| +		struct sched_domain *parent = tmp->parent;
 | |
| +		if (!parent)
 | |
| +			break;
 | |
| +
 | |
| +		if (sd_parent_degenerate(tmp, parent)) {
 | |
| +			tmp->parent = parent->parent;
 | |
| +			if (parent->parent)
 | |
| +				parent->parent->child = tmp;
 | |
| +		} else
 | |
| +			tmp = tmp->parent;
 | |
| +	}
 | |
| +
 | |
| +	if (sd && sd_degenerate(sd)) {
 | |
| +		sd = sd->parent;
 | |
| +		if (sd)
 | |
| +			sd->child = NULL;
 | |
| +	}
 | |
| +
 | |
| +	sched_domain_debug(sd, cpu);
 | |
| +
 | |
| +	rq_attach_root(rq, rd);
 | |
| +	rcu_assign_pointer(rq->sd, sd);
 | |
| +}
 | |
| +
 | |
| +/* cpus with isolated domains */
 | |
| +static cpumask_var_t cpu_isolated_map;
 | |
| +
 | |
| +/* Setup the mask of cpus configured for isolated domains */
 | |
| +static int __init isolated_cpu_setup(char *str)
 | |
| +{
 | |
| +	cpulist_parse(str, cpu_isolated_map);
 | |
| +	return 1;
 | |
| +}
 | |
| +
 | |
| +__setup("isolcpus=", isolated_cpu_setup);
 | |
| +
 | |
| +/*
 | |
| + * init_sched_build_groups takes the cpumask we wish to span, and a pointer
 | |
| + * to a function which identifies what group(along with sched group) a CPU
 | |
| + * belongs to. The return value of group_fn must be a >= 0 and < nr_cpu_ids
 | |
| + * (due to the fact that we keep track of groups covered with a struct cpumask).
 | |
| + *
 | |
| + * init_sched_build_groups will build a circular linked list of the groups
 | |
| + * covered by the given span, and will set each group's ->cpumask correctly,
 | |
| + * and ->cpu_power to 0.
 | |
| + */
 | |
| +static void
 | |
| +init_sched_build_groups(const struct cpumask *span,
 | |
| +			const struct cpumask *cpu_map,
 | |
| +			int (*group_fn)(int cpu, const struct cpumask *cpu_map,
 | |
| +					struct sched_group **sg,
 | |
| +					struct cpumask *tmpmask),
 | |
| +			struct cpumask *covered, struct cpumask *tmpmask)
 | |
| +{
 | |
| +	struct sched_group *first = NULL, *last = NULL;
 | |
| +	int i;
 | |
| +
 | |
| +	cpumask_clear(covered);
 | |
| +
 | |
| +	for_each_cpu(i, span) {
 | |
| +		struct sched_group *sg;
 | |
| +		int group = group_fn(i, cpu_map, &sg, tmpmask);
 | |
| +		int j;
 | |
| +
 | |
| +		if (cpumask_test_cpu(i, covered))
 | |
| +			continue;
 | |
| +
 | |
| +		cpumask_clear(sched_group_cpus(sg));
 | |
| +		sg->__cpu_power = 0;
 | |
| +
 | |
| +		for_each_cpu(j, span) {
 | |
| +			if (group_fn(j, cpu_map, NULL, tmpmask) != group)
 | |
| +				continue;
 | |
| +
 | |
| +			cpumask_set_cpu(j, covered);
 | |
| +			cpumask_set_cpu(j, sched_group_cpus(sg));
 | |
| +		}
 | |
| +		if (!first)
 | |
| +			first = sg;
 | |
| +		if (last)
 | |
| +			last->next = sg;
 | |
| +		last = sg;
 | |
| +	}
 | |
| +	last->next = first;
 | |
| +}
 | |
| +
 | |
| +#define SD_NODES_PER_DOMAIN 16
 | |
| +
 | |
| +#ifdef CONFIG_NUMA
 | |
| +
 | |
| +/**
 | |
| + * find_next_best_node - find the next node to include in a sched_domain
 | |
| + * @node: node whose sched_domain we're building
 | |
| + * @used_nodes: nodes already in the sched_domain
 | |
| + *
 | |
| + * Find the next node to include in a given scheduling domain. Simply
 | |
| + * finds the closest node not already in the @used_nodes map.
 | |
| + *
 | |
| + * Should use nodemask_t.
 | |
| + */
 | |
| +static int find_next_best_node(int node, nodemask_t *used_nodes)
 | |
| +{
 | |
| +	int i, n, val, min_val, best_node = 0;
 | |
| +
 | |
| +	min_val = INT_MAX;
 | |
| +
 | |
| +	for (i = 0; i < nr_node_ids; i++) {
 | |
| +		/* Start at @node */
 | |
| +		n = (node + i) % nr_node_ids;
 | |
| +
 | |
| +		if (!nr_cpus_node(n))
 | |
| +			continue;
 | |
| +
 | |
| +		/* Skip already used nodes */
 | |
| +		if (node_isset(n, *used_nodes))
 | |
| +			continue;
 | |
| +
 | |
| +		/* Simple min distance search */
 | |
| +		val = node_distance(node, n);
 | |
| +
 | |
| +		if (val < min_val) {
 | |
| +			min_val = val;
 | |
| +			best_node = n;
 | |
| +		}
 | |
| +	}
 | |
| +
 | |
| +	node_set(best_node, *used_nodes);
 | |
| +	return best_node;
 | |
| +}
 | |
| +
 | |
| +/**
 | |
| + * sched_domain_node_span - get a cpumask for a node's sched_domain
 | |
| + * @node: node whose cpumask we're constructing
 | |
| + * @span: resulting cpumask
 | |
| + *
 | |
| + * Given a node, construct a good cpumask for its sched_domain to span. It
 | |
| + * should be one that prevents unnecessary balancing, but also spreads tasks
 | |
| + * out optimally.
 | |
| + */
 | |
| +static void sched_domain_node_span(int node, struct cpumask *span)
 | |
| +{
 | |
| +	nodemask_t used_nodes;
 | |
| +	int i;
 | |
| +
 | |
| +	cpumask_clear(span);
 | |
| +	nodes_clear(used_nodes);
 | |
| +
 | |
| +	cpumask_or(span, span, cpumask_of_node(node));
 | |
| +	node_set(node, used_nodes);
 | |
| +
 | |
| +	for (i = 1; i < SD_NODES_PER_DOMAIN; i++) {
 | |
| +		int next_node = find_next_best_node(node, &used_nodes);
 | |
| +
 | |
| +		cpumask_or(span, span, cpumask_of_node(next_node));
 | |
| +	}
 | |
| +}
 | |
| +#endif /* CONFIG_NUMA */
 | |
| +
 | |
| +int sched_smt_power_savings = 0, sched_mc_power_savings = 0;
 | |
| +
 | |
| +/*
 | |
| + * The cpus mask in sched_group and sched_domain hangs off the end.
 | |
| + *
 | |
| + * ( See the the comments in include/linux/sched.h:struct sched_group
 | |
| + *   and struct sched_domain. )
 | |
| + */
 | |
| +struct static_sched_group {
 | |
| +	struct sched_group sg;
 | |
| +	DECLARE_BITMAP(cpus, CONFIG_NR_CPUS);
 | |
| +};
 | |
| +
 | |
| +struct static_sched_domain {
 | |
| +	struct sched_domain sd;
 | |
| +	DECLARE_BITMAP(span, CONFIG_NR_CPUS);
 | |
| +};
 | |
| +
 | |
| +/*
 | |
| + * SMT sched-domains:
 | |
| + */
 | |
| +#ifdef CONFIG_SCHED_SMT
 | |
| +static DEFINE_PER_CPU(struct static_sched_domain, cpu_domains);
 | |
| +static DEFINE_PER_CPU(struct static_sched_group, sched_group_cpus);
 | |
| +
 | |
| +static int
 | |
| +cpu_to_cpu_group(int cpu, const struct cpumask *cpu_map,
 | |
| +		 struct sched_group **sg, struct cpumask *unused)
 | |
| +{
 | |
| +	if (sg)
 | |
| +		*sg = &per_cpu(sched_group_cpus, cpu).sg;
 | |
| +	return cpu;
 | |
| +}
 | |
| +#endif /* CONFIG_SCHED_SMT */
 | |
| +
 | |
| +/*
 | |
| + * multi-core sched-domains:
 | |
| + */
 | |
| +#ifdef CONFIG_SCHED_MC
 | |
| +static DEFINE_PER_CPU(struct static_sched_domain, core_domains);
 | |
| +static DEFINE_PER_CPU(struct static_sched_group, sched_group_core);
 | |
| +#endif /* CONFIG_SCHED_MC */
 | |
| +
 | |
| +#if defined(CONFIG_SCHED_MC) && defined(CONFIG_SCHED_SMT)
 | |
| +static int
 | |
| +cpu_to_core_group(int cpu, const struct cpumask *cpu_map,
 | |
| +		  struct sched_group **sg, struct cpumask *mask)
 | |
| +{
 | |
| +	int group;
 | |
| +
 | |
| +	cpumask_and(mask, topology_thread_cpumask(cpu), cpu_map);
 | |
| +	group = cpumask_first(mask);
 | |
| +	if (sg)
 | |
| +		*sg = &per_cpu(sched_group_core, group).sg;
 | |
| +	return group;
 | |
| +}
 | |
| +#elif defined(CONFIG_SCHED_MC)
 | |
| +static int
 | |
| +cpu_to_core_group(int cpu, const struct cpumask *cpu_map,
 | |
| +		  struct sched_group **sg, struct cpumask *unused)
 | |
| +{
 | |
| +	if (sg)
 | |
| +		*sg = &per_cpu(sched_group_core, cpu).sg;
 | |
| +	return cpu;
 | |
| +}
 | |
| +#endif
 | |
| +
 | |
| +static DEFINE_PER_CPU(struct static_sched_domain, phys_domains);
 | |
| +static DEFINE_PER_CPU(struct static_sched_group, sched_group_phys);
 | |
| +
 | |
| +static int
 | |
| +cpu_to_phys_group(int cpu, const struct cpumask *cpu_map,
 | |
| +		  struct sched_group **sg, struct cpumask *mask)
 | |
| +{
 | |
| +	int group;
 | |
| +#ifdef CONFIG_SCHED_MC
 | |
| +	cpumask_and(mask, cpu_coregroup_mask(cpu), cpu_map);
 | |
| +	group = cpumask_first(mask);
 | |
| +#elif defined(CONFIG_SCHED_SMT)
 | |
| +	cpumask_and(mask, topology_thread_cpumask(cpu), cpu_map);
 | |
| +	group = cpumask_first(mask);
 | |
| +#else
 | |
| +	group = cpu;
 | |
| +#endif
 | |
| +	if (sg)
 | |
| +		*sg = &per_cpu(sched_group_phys, group).sg;
 | |
| +	return group;
 | |
| +}
 | |
| +
 | |
| +/**
 | |
| + * group_first_cpu - Returns the first cpu in the cpumask of a sched_group.
 | |
| + * @group: The group whose first cpu is to be returned.
 | |
| + */
 | |
| +static inline unsigned int group_first_cpu(struct sched_group *group)
 | |
| +{
 | |
| +	return cpumask_first(sched_group_cpus(group));
 | |
| +}
 | |
| +
 | |
| +#ifdef CONFIG_NUMA
 | |
| +/*
 | |
| + * The init_sched_build_groups can't handle what we want to do with node
 | |
| + * groups, so roll our own. Now each node has its own list of groups which
 | |
| + * gets dynamically allocated.
 | |
| + */
 | |
| +static DEFINE_PER_CPU(struct static_sched_domain, node_domains);
 | |
| +static struct sched_group ***sched_group_nodes_bycpu;
 | |
| +
 | |
| +static DEFINE_PER_CPU(struct static_sched_domain, allnodes_domains);
 | |
| +static DEFINE_PER_CPU(struct static_sched_group, sched_group_allnodes);
 | |
| +
 | |
| +static int cpu_to_allnodes_group(int cpu, const struct cpumask *cpu_map,
 | |
| +				 struct sched_group **sg,
 | |
| +				 struct cpumask *nodemask)
 | |
| +{
 | |
| +	int group;
 | |
| +
 | |
| +	cpumask_and(nodemask, cpumask_of_node(cpu_to_node(cpu)), cpu_map);
 | |
| +	group = cpumask_first(nodemask);
 | |
| +
 | |
| +	if (sg)
 | |
| +		*sg = &per_cpu(sched_group_allnodes, group).sg;
 | |
| +	return group;
 | |
| +}
 | |
| +
 | |
| +static void init_numa_sched_groups_power(struct sched_group *group_head)
 | |
| +{
 | |
| +	struct sched_group *sg = group_head;
 | |
| +	int j;
 | |
| +
 | |
| +	if (!sg)
 | |
| +		return;
 | |
| +	do {
 | |
| +		for_each_cpu(j, sched_group_cpus(sg)) {
 | |
| +			struct sched_domain *sd;
 | |
| +
 | |
| +			sd = &per_cpu(phys_domains, j).sd;
 | |
| +			if (j != group_first_cpu(sd->groups)) {
 | |
| +				/*
 | |
| +				 * Only add "power" once for each
 | |
| +				 * physical package.
 | |
| +				 */
 | |
| +				continue;
 | |
| +			}
 | |
| +
 | |
| +			sg_inc_cpu_power(sg, sd->groups->__cpu_power);
 | |
| +		}
 | |
| +		sg = sg->next;
 | |
| +	} while (sg != group_head);
 | |
| +}
 | |
| +#endif /* CONFIG_NUMA */
 | |
| +
 | |
| +#ifdef CONFIG_NUMA
 | |
| +/* Free memory allocated for various sched_group structures */
 | |
| +static void free_sched_groups(const struct cpumask *cpu_map,
 | |
| +			      struct cpumask *nodemask)
 | |
| +{
 | |
| +	int cpu, i;
 | |
| +
 | |
| +	for_each_cpu(cpu, cpu_map) {
 | |
| +		struct sched_group **sched_group_nodes
 | |
| +			= sched_group_nodes_bycpu[cpu];
 | |
| +
 | |
| +		if (!sched_group_nodes)
 | |
| +			continue;
 | |
| +
 | |
| +		for (i = 0; i < nr_node_ids; i++) {
 | |
| +			struct sched_group *oldsg, *sg = sched_group_nodes[i];
 | |
| +
 | |
| +			cpumask_and(nodemask, cpumask_of_node(i), cpu_map);
 | |
| +			if (cpumask_empty(nodemask))
 | |
| +				continue;
 | |
| +
 | |
| +			if (sg == NULL)
 | |
| +				continue;
 | |
| +			sg = sg->next;
 | |
| +next_sg:
 | |
| +			oldsg = sg;
 | |
| +			sg = sg->next;
 | |
| +			kfree(oldsg);
 | |
| +			if (oldsg != sched_group_nodes[i])
 | |
| +				goto next_sg;
 | |
| +		}
 | |
| +		kfree(sched_group_nodes);
 | |
| +		sched_group_nodes_bycpu[cpu] = NULL;
 | |
| +	}
 | |
| +}
 | |
| +#else /* !CONFIG_NUMA */
 | |
| +static void free_sched_groups(const struct cpumask *cpu_map,
 | |
| +			      struct cpumask *nodemask)
 | |
| +{
 | |
| +}
 | |
| +#endif /* CONFIG_NUMA */
 | |
| +
 | |
| +/*
 | |
| + * Initialize sched groups cpu_power.
 | |
| + *
 | |
| + * cpu_power indicates the capacity of sched group, which is used while
 | |
| + * distributing the load between different sched groups in a sched domain.
 | |
| + * Typically cpu_power for all the groups in a sched domain will be same unless
 | |
| + * there are asymmetries in the topology. If there are asymmetries, group
 | |
| + * having more cpu_power will pickup more load compared to the group having
 | |
| + * less cpu_power.
 | |
| + *
 | |
| + * cpu_power will be a multiple of SCHED_LOAD_SCALE. This multiple represents
 | |
| + * the maximum number of tasks a group can handle in the presence of other idle
 | |
| + * or lightly loaded groups in the same sched domain.
 | |
| + */
 | |
| +static void init_sched_groups_power(int cpu, struct sched_domain *sd)
 | |
| +{
 | |
| +	struct sched_domain *child;
 | |
| +	struct sched_group *group;
 | |
| +
 | |
| +	WARN_ON(!sd || !sd->groups);
 | |
| +
 | |
| +	if (cpu != group_first_cpu(sd->groups))
 | |
| +		return;
 | |
| +
 | |
| +	child = sd->child;
 | |
| +
 | |
| +	sd->groups->__cpu_power = 0;
 | |
| +
 | |
| +	/*
 | |
| +	 * For perf policy, if the groups in child domain share resources
 | |
| +	 * (for example cores sharing some portions of the cache hierarchy
 | |
| +	 * or SMT), then set this domain groups cpu_power such that each group
 | |
| +	 * can handle only one task, when there are other idle groups in the
 | |
| +	 * same sched domain.
 | |
| +	 */
 | |
| +	if (!child || (!(sd->flags & SD_POWERSAVINGS_BALANCE) &&
 | |
| +		       (child->flags &
 | |
| +			(SD_SHARE_CPUPOWER | SD_SHARE_PKG_RESOURCES)))) {
 | |
| +		sg_inc_cpu_power(sd->groups, SCHED_LOAD_SCALE);
 | |
| +		return;
 | |
| +	}
 | |
| +
 | |
| +	/*
 | |
| +	 * add cpu_power of each child group to this groups cpu_power
 | |
| +	 */
 | |
| +	group = child->groups;
 | |
| +	do {
 | |
| +		sg_inc_cpu_power(sd->groups, group->__cpu_power);
 | |
| +		group = group->next;
 | |
| +	} while (group != child->groups);
 | |
| +}
 | |
| +
 | |
| +/*
 | |
| + * Initializers for schedule domains
 | |
| + * Non-inlined to reduce accumulated stack pressure in build_sched_domains()
 | |
| + */
 | |
| +
 | |
| +#ifdef CONFIG_SCHED_DEBUG
 | |
| +# define SD_INIT_NAME(sd, type)		sd->name = #type
 | |
| +#else
 | |
| +# define SD_INIT_NAME(sd, type)		do { } while (0)
 | |
| +#endif
 | |
| +
 | |
| +#define	SD_INIT(sd, type)	sd_init_##type(sd)
 | |
| +
 | |
| +#define SD_INIT_FUNC(type)	\
 | |
| +static noinline void sd_init_##type(struct sched_domain *sd)	\
 | |
| +{								\
 | |
| +	memset(sd, 0, sizeof(*sd));				\
 | |
| +	*sd = SD_##type##_INIT;					\
 | |
| +	sd->level = SD_LV_##type;				\
 | |
| +	SD_INIT_NAME(sd, type);					\
 | |
| +}
 | |
| +
 | |
| +SD_INIT_FUNC(CPU)
 | |
| +#ifdef CONFIG_NUMA
 | |
| + SD_INIT_FUNC(ALLNODES)
 | |
| + SD_INIT_FUNC(NODE)
 | |
| +#endif
 | |
| +#ifdef CONFIG_SCHED_SMT
 | |
| + SD_INIT_FUNC(SIBLING)
 | |
| +#endif
 | |
| +#ifdef CONFIG_SCHED_MC
 | |
| + SD_INIT_FUNC(MC)
 | |
| +#endif
 | |
| +
 | |
| +static int default_relax_domain_level = -1;
 | |
| +
 | |
| +static int __init setup_relax_domain_level(char *str)
 | |
| +{
 | |
| +	unsigned long val;
 | |
| +
 | |
| +	val = simple_strtoul(str, NULL, 0);
 | |
| +	if (val < SD_LV_MAX)
 | |
| +		default_relax_domain_level = val;
 | |
| +
 | |
| +	return 1;
 | |
| +}
 | |
| +__setup("relax_domain_level=", setup_relax_domain_level);
 | |
| +
 | |
| +static void set_domain_attribute(struct sched_domain *sd,
 | |
| +				 struct sched_domain_attr *attr)
 | |
| +{
 | |
| +	int request;
 | |
| +
 | |
| +	if (!attr || attr->relax_domain_level < 0) {
 | |
| +		if (default_relax_domain_level < 0)
 | |
| +			return;
 | |
| +		else
 | |
| +			request = default_relax_domain_level;
 | |
| +	} else
 | |
| +		request = attr->relax_domain_level;
 | |
| +	if (request < sd->level) {
 | |
| +		/* turn off idle balance on this domain */
 | |
| +		sd->flags &= ~(SD_WAKE_IDLE|SD_BALANCE_NEWIDLE);
 | |
| +	} else {
 | |
| +		/* turn on idle balance on this domain */
 | |
| +		sd->flags |= (SD_WAKE_IDLE_FAR|SD_BALANCE_NEWIDLE);
 | |
| +	}
 | |
| +}
 | |
| +
 | |
| +/*
 | |
| + * Build sched domains for a given set of cpus and attach the sched domains
 | |
| + * to the individual cpus
 | |
| + */
 | |
| +static int __build_sched_domains(const struct cpumask *cpu_map,
 | |
| +				 struct sched_domain_attr *attr)
 | |
| +{
 | |
| +	int i, err = -ENOMEM;
 | |
| +	struct root_domain *rd;
 | |
| +	cpumask_var_t nodemask, this_sibling_map, this_core_map, send_covered,
 | |
| +		tmpmask;
 | |
| +#ifdef CONFIG_NUMA
 | |
| +	cpumask_var_t domainspan, covered, notcovered;
 | |
| +	struct sched_group **sched_group_nodes = NULL;
 | |
| +	int sd_allnodes = 0;
 | |
| +
 | |
| +	if (!alloc_cpumask_var(&domainspan, GFP_KERNEL))
 | |
| +		goto out;
 | |
| +	if (!alloc_cpumask_var(&covered, GFP_KERNEL))
 | |
| +		goto free_domainspan;
 | |
| +	if (!alloc_cpumask_var(¬covered, GFP_KERNEL))
 | |
| +		goto free_covered;
 | |
| +#endif
 | |
| +
 | |
| +	if (!alloc_cpumask_var(&nodemask, GFP_KERNEL))
 | |
| +		goto free_notcovered;
 | |
| +	if (!alloc_cpumask_var(&this_sibling_map, GFP_KERNEL))
 | |
| +		goto free_nodemask;
 | |
| +	if (!alloc_cpumask_var(&this_core_map, GFP_KERNEL))
 | |
| +		goto free_this_sibling_map;
 | |
| +	if (!alloc_cpumask_var(&send_covered, GFP_KERNEL))
 | |
| +		goto free_this_core_map;
 | |
| +	if (!alloc_cpumask_var(&tmpmask, GFP_KERNEL))
 | |
| +		goto free_send_covered;
 | |
| +
 | |
| +#ifdef CONFIG_NUMA
 | |
| +	/*
 | |
| +	 * Allocate the per-node list of sched groups
 | |
| +	 */
 | |
| +	sched_group_nodes = kcalloc(nr_node_ids, sizeof(struct sched_group *),
 | |
| +				    GFP_KERNEL);
 | |
| +	if (!sched_group_nodes) {
 | |
| +		printk(KERN_WARNING "Can not alloc sched group node list\n");
 | |
| +		goto free_tmpmask;
 | |
| +	}
 | |
| +#endif
 | |
| +
 | |
| +	rd = alloc_rootdomain();
 | |
| +	if (!rd) {
 | |
| +		printk(KERN_WARNING "Cannot alloc root domain\n");
 | |
| +		goto free_sched_groups;
 | |
| +	}
 | |
| +
 | |
| +#ifdef CONFIG_NUMA
 | |
| +	sched_group_nodes_bycpu[cpumask_first(cpu_map)] = sched_group_nodes;
 | |
| +#endif
 | |
| +
 | |
| +	/*
 | |
| +	 * Set up domains for cpus specified by the cpu_map.
 | |
| +	 */
 | |
| +	for_each_cpu(i, cpu_map) {
 | |
| +		struct sched_domain *sd = NULL, *p;
 | |
| +
 | |
| +		cpumask_and(nodemask, cpumask_of_node(cpu_to_node(i)), cpu_map);
 | |
| +
 | |
| +#ifdef CONFIG_NUMA
 | |
| +		if (cpumask_weight(cpu_map) >
 | |
| +				SD_NODES_PER_DOMAIN*cpumask_weight(nodemask)) {
 | |
| +			sd = &per_cpu(allnodes_domains, i).sd;
 | |
| +			SD_INIT(sd, ALLNODES);
 | |
| +			set_domain_attribute(sd, attr);
 | |
| +			cpumask_copy(sched_domain_span(sd), cpu_map);
 | |
| +			cpu_to_allnodes_group(i, cpu_map, &sd->groups, tmpmask);
 | |
| +			p = sd;
 | |
| +			sd_allnodes = 1;
 | |
| +		} else
 | |
| +			p = NULL;
 | |
| +
 | |
| +		sd = &per_cpu(node_domains, i).sd;
 | |
| +		SD_INIT(sd, NODE);
 | |
| +		set_domain_attribute(sd, attr);
 | |
| +		sched_domain_node_span(cpu_to_node(i), sched_domain_span(sd));
 | |
| +		sd->parent = p;
 | |
| +		if (p)
 | |
| +			p->child = sd;
 | |
| +		cpumask_and(sched_domain_span(sd),
 | |
| +			    sched_domain_span(sd), cpu_map);
 | |
| +#endif
 | |
| +
 | |
| +		p = sd;
 | |
| +		sd = &per_cpu(phys_domains, i).sd;
 | |
| +		SD_INIT(sd, CPU);
 | |
| +		set_domain_attribute(sd, attr);
 | |
| +		cpumask_copy(sched_domain_span(sd), nodemask);
 | |
| +		sd->parent = p;
 | |
| +		if (p)
 | |
| +			p->child = sd;
 | |
| +		cpu_to_phys_group(i, cpu_map, &sd->groups, tmpmask);
 | |
| +
 | |
| +#ifdef CONFIG_SCHED_MC
 | |
| +		p = sd;
 | |
| +		sd = &per_cpu(core_domains, i).sd;
 | |
| +		SD_INIT(sd, MC);
 | |
| +		set_domain_attribute(sd, attr);
 | |
| +		cpumask_and(sched_domain_span(sd), cpu_map,
 | |
| +						   cpu_coregroup_mask(i));
 | |
| +		sd->parent = p;
 | |
| +		p->child = sd;
 | |
| +		cpu_to_core_group(i, cpu_map, &sd->groups, tmpmask);
 | |
| +#endif
 | |
| +
 | |
| +#ifdef CONFIG_SCHED_SMT
 | |
| +		p = sd;
 | |
| +		sd = &per_cpu(cpu_domains, i).sd;
 | |
| +		SD_INIT(sd, SIBLING);
 | |
| +		set_domain_attribute(sd, attr);
 | |
| +		cpumask_and(sched_domain_span(sd),
 | |
| +			    topology_thread_cpumask(i), cpu_map);
 | |
| +		sd->parent = p;
 | |
| +		p->child = sd;
 | |
| +		cpu_to_cpu_group(i, cpu_map, &sd->groups, tmpmask);
 | |
| +#endif
 | |
| +	}
 | |
| +
 | |
| +#ifdef CONFIG_SCHED_SMT
 | |
| +	/* Set up CPU (sibling) groups */
 | |
| +	for_each_cpu(i, cpu_map) {
 | |
| +		cpumask_and(this_sibling_map,
 | |
| +			    topology_thread_cpumask(i), cpu_map);
 | |
| +		if (i != cpumask_first(this_sibling_map))
 | |
| +			continue;
 | |
| +
 | |
| +		init_sched_build_groups(this_sibling_map, cpu_map,
 | |
| +					&cpu_to_cpu_group,
 | |
| +					send_covered, tmpmask);
 | |
| +	}
 | |
| +#endif
 | |
| +
 | |
| +#ifdef CONFIG_SCHED_MC
 | |
| +	/* Set up multi-core groups */
 | |
| +	for_each_cpu(i, cpu_map) {
 | |
| +		cpumask_and(this_core_map, cpu_coregroup_mask(i), cpu_map);
 | |
| +		if (i != cpumask_first(this_core_map))
 | |
| +			continue;
 | |
| +
 | |
| +		init_sched_build_groups(this_core_map, cpu_map,
 | |
| +					&cpu_to_core_group,
 | |
| +					send_covered, tmpmask);
 | |
| +	}
 | |
| +#endif
 | |
| +
 | |
| +	/* Set up physical groups */
 | |
| +	for (i = 0; i < nr_node_ids; i++) {
 | |
| +		cpumask_and(nodemask, cpumask_of_node(i), cpu_map);
 | |
| +		if (cpumask_empty(nodemask))
 | |
| +			continue;
 | |
| +
 | |
| +		init_sched_build_groups(nodemask, cpu_map,
 | |
| +					&cpu_to_phys_group,
 | |
| +					send_covered, tmpmask);
 | |
| +	}
 | |
| +
 | |
| +#ifdef CONFIG_NUMA
 | |
| +	/* Set up node groups */
 | |
| +	if (sd_allnodes) {
 | |
| +		init_sched_build_groups(cpu_map, cpu_map,
 | |
| +					&cpu_to_allnodes_group,
 | |
| +					send_covered, tmpmask);
 | |
| +	}
 | |
| +
 | |
| +	for (i = 0; i < nr_node_ids; i++) {
 | |
| +		/* Set up node groups */
 | |
| +		struct sched_group *sg, *prev;
 | |
| +		int j;
 | |
| +
 | |
| +		cpumask_clear(covered);
 | |
| +		cpumask_and(nodemask, cpumask_of_node(i), cpu_map);
 | |
| +		if (cpumask_empty(nodemask)) {
 | |
| +			sched_group_nodes[i] = NULL;
 | |
| +			continue;
 | |
| +		}
 | |
| +
 | |
| +		sched_domain_node_span(i, domainspan);
 | |
| +		cpumask_and(domainspan, domainspan, cpu_map);
 | |
| +
 | |
| +		sg = kmalloc_node(sizeof(struct sched_group) + cpumask_size(),
 | |
| +				  GFP_KERNEL, i);
 | |
| +		if (!sg) {
 | |
| +			printk(KERN_WARNING "Can not alloc domain group for "
 | |
| +				"node %d\n", i);
 | |
| +			goto error;
 | |
| +		}
 | |
| +		sched_group_nodes[i] = sg;
 | |
| +		for_each_cpu(j, nodemask) {
 | |
| +			struct sched_domain *sd;
 | |
| +
 | |
| +			sd = &per_cpu(node_domains, j).sd;
 | |
| +			sd->groups = sg;
 | |
| +		}
 | |
| +		sg->__cpu_power = 0;
 | |
| +		cpumask_copy(sched_group_cpus(sg), nodemask);
 | |
| +		sg->next = sg;
 | |
| +		cpumask_or(covered, covered, nodemask);
 | |
| +		prev = sg;
 | |
| +
 | |
| +		for (j = 0; j < nr_node_ids; j++) {
 | |
| +			int n = (i + j) % nr_node_ids;
 | |
| +
 | |
| +			cpumask_complement(notcovered, covered);
 | |
| +			cpumask_and(tmpmask, notcovered, cpu_map);
 | |
| +			cpumask_and(tmpmask, tmpmask, domainspan);
 | |
| +			if (cpumask_empty(tmpmask))
 | |
| +				break;
 | |
| +
 | |
| +			cpumask_and(tmpmask, tmpmask, cpumask_of_node(n));
 | |
| +			if (cpumask_empty(tmpmask))
 | |
| +				continue;
 | |
| +
 | |
| +			sg = kmalloc_node(sizeof(struct sched_group) +
 | |
| +					  cpumask_size(),
 | |
| +					  GFP_KERNEL, i);
 | |
| +			if (!sg) {
 | |
| +				printk(KERN_WARNING
 | |
| +				"Can not alloc domain group for node %d\n", j);
 | |
| +				goto error;
 | |
| +			}
 | |
| +			sg->__cpu_power = 0;
 | |
| +			cpumask_copy(sched_group_cpus(sg), tmpmask);
 | |
| +			sg->next = prev->next;
 | |
| +			cpumask_or(covered, covered, tmpmask);
 | |
| +			prev->next = sg;
 | |
| +			prev = sg;
 | |
| +		}
 | |
| +	}
 | |
| +#endif
 | |
| +
 | |
| +	/* Calculate CPU power for physical packages and nodes */
 | |
| +#ifdef CONFIG_SCHED_SMT
 | |
| +	for_each_cpu(i, cpu_map) {
 | |
| +		struct sched_domain *sd = &per_cpu(cpu_domains, i).sd;
 | |
| +
 | |
| +		init_sched_groups_power(i, sd);
 | |
| +	}
 | |
| +#endif
 | |
| +#ifdef CONFIG_SCHED_MC
 | |
| +	for_each_cpu(i, cpu_map) {
 | |
| +		struct sched_domain *sd = &per_cpu(core_domains, i).sd;
 | |
| +
 | |
| +		init_sched_groups_power(i, sd);
 | |
| +	}
 | |
| +#endif
 | |
| +
 | |
| +	for_each_cpu(i, cpu_map) {
 | |
| +		struct sched_domain *sd = &per_cpu(phys_domains, i).sd;
 | |
| +
 | |
| +		init_sched_groups_power(i, sd);
 | |
| +	}
 | |
| +
 | |
| +#ifdef CONFIG_NUMA
 | |
| +	for (i = 0; i < nr_node_ids; i++)
 | |
| +		init_numa_sched_groups_power(sched_group_nodes[i]);
 | |
| +
 | |
| +	if (sd_allnodes) {
 | |
| +		struct sched_group *sg;
 | |
| +
 | |
| +		cpu_to_allnodes_group(cpumask_first(cpu_map), cpu_map, &sg,
 | |
| +								tmpmask);
 | |
| +		init_numa_sched_groups_power(sg);
 | |
| +	}
 | |
| +#endif
 | |
| +
 | |
| +	/* Attach the domains */
 | |
| +	for_each_cpu(i, cpu_map) {
 | |
| +		struct sched_domain *sd;
 | |
| +#ifdef CONFIG_SCHED_SMT
 | |
| +		sd = &per_cpu(cpu_domains, i).sd;
 | |
| +#elif defined(CONFIG_SCHED_MC)
 | |
| +		sd = &per_cpu(core_domains, i).sd;
 | |
| +#else
 | |
| +		sd = &per_cpu(phys_domains, i).sd;
 | |
| +#endif
 | |
| +		cpu_attach_domain(sd, rd, i);
 | |
| +	}
 | |
| +
 | |
| +	err = 0;
 | |
| +
 | |
| +free_tmpmask:
 | |
| +	free_cpumask_var(tmpmask);
 | |
| +free_send_covered:
 | |
| +	free_cpumask_var(send_covered);
 | |
| +free_this_core_map:
 | |
| +	free_cpumask_var(this_core_map);
 | |
| +free_this_sibling_map:
 | |
| +	free_cpumask_var(this_sibling_map);
 | |
| +free_nodemask:
 | |
| +	free_cpumask_var(nodemask);
 | |
| +free_notcovered:
 | |
| +#ifdef CONFIG_NUMA
 | |
| +	free_cpumask_var(notcovered);
 | |
| +free_covered:
 | |
| +	free_cpumask_var(covered);
 | |
| +free_domainspan:
 | |
| +	free_cpumask_var(domainspan);
 | |
| +out:
 | |
| +#endif
 | |
| +	return err;
 | |
| +
 | |
| +free_sched_groups:
 | |
| +#ifdef CONFIG_NUMA
 | |
| +	kfree(sched_group_nodes);
 | |
| +#endif
 | |
| +	goto free_tmpmask;
 | |
| +
 | |
| +#ifdef CONFIG_NUMA
 | |
| +error:
 | |
| +	free_sched_groups(cpu_map, tmpmask);
 | |
| +	free_rootdomain(rd);
 | |
| +	goto free_tmpmask;
 | |
| +#endif
 | |
| +}
 | |
| +
 | |
| +static int build_sched_domains(const struct cpumask *cpu_map)
 | |
| +{
 | |
| +	return __build_sched_domains(cpu_map, NULL);
 | |
| +}
 | |
| +
 | |
| +static struct cpumask *doms_cur;	/* current sched domains */
 | |
| +static int ndoms_cur;		/* number of sched domains in 'doms_cur' */
 | |
| +static struct sched_domain_attr *dattr_cur;
 | |
| +				/* attribues of custom domains in 'doms_cur' */
 | |
| +
 | |
| +/*
 | |
| + * Special case: If a kmalloc of a doms_cur partition (array of
 | |
| + * cpumask) fails, then fallback to a single sched domain,
 | |
| + * as determined by the single cpumask fallback_doms.
 | |
| + */
 | |
| +static cpumask_var_t fallback_doms;
 | |
| +
 | |
| +/*
 | |
| + * arch_update_cpu_topology lets virtualized architectures update the
 | |
| + * cpu core maps. It is supposed to return 1 if the topology changed
 | |
| + * or 0 if it stayed the same.
 | |
| + */
 | |
| +int __attribute__((weak)) arch_update_cpu_topology(void)
 | |
| +{
 | |
| +	return 0;
 | |
| +}
 | |
| +
 | |
| +/*
 | |
| + * Set up scheduler domains and groups. Callers must hold the hotplug lock.
 | |
| + * For now this just excludes isolated cpus, but could be used to
 | |
| + * exclude other special cases in the future.
 | |
| + */
 | |
| +static int arch_init_sched_domains(const struct cpumask *cpu_map)
 | |
| +{
 | |
| +	int err;
 | |
| +
 | |
| +	arch_update_cpu_topology();
 | |
| +	ndoms_cur = 1;
 | |
| +	doms_cur = kmalloc(cpumask_size(), GFP_KERNEL);
 | |
| +	if (!doms_cur)
 | |
| +		doms_cur = fallback_doms;
 | |
| +	cpumask_andnot(doms_cur, cpu_map, cpu_isolated_map);
 | |
| +	dattr_cur = NULL;
 | |
| +	err = build_sched_domains(doms_cur);
 | |
| +	register_sched_domain_sysctl();
 | |
| +
 | |
| +	return err;
 | |
| +}
 | |
| +
 | |
| +static void arch_destroy_sched_domains(const struct cpumask *cpu_map,
 | |
| +				       struct cpumask *tmpmask)
 | |
| +{
 | |
| +	free_sched_groups(cpu_map, tmpmask);
 | |
| +}
 | |
| +
 | |
| +/*
 | |
| + * Detach sched domains from a group of cpus specified in cpu_map
 | |
| + * These cpus will now be attached to the NULL domain
 | |
| + */
 | |
| +static void detach_destroy_domains(const struct cpumask *cpu_map)
 | |
| +{
 | |
| +	/* Save because hotplug lock held. */
 | |
| +	static DECLARE_BITMAP(tmpmask, CONFIG_NR_CPUS);
 | |
| +	int i;
 | |
| +
 | |
| +	for_each_cpu(i, cpu_map)
 | |
| +		cpu_attach_domain(NULL, &def_root_domain, i);
 | |
| +	synchronize_sched();
 | |
| +	arch_destroy_sched_domains(cpu_map, to_cpumask(tmpmask));
 | |
| +}
 | |
| +
 | |
| +/* handle null as "default" */
 | |
| +static int dattrs_equal(struct sched_domain_attr *cur, int idx_cur,
 | |
| +			struct sched_domain_attr *new, int idx_new)
 | |
| +{
 | |
| +	struct sched_domain_attr tmp;
 | |
| +
 | |
| +	/* fast path */
 | |
| +	if (!new && !cur)
 | |
| +		return 1;
 | |
| +
 | |
| +	tmp = SD_ATTR_INIT;
 | |
| +	return !memcmp(cur ? (cur + idx_cur) : &tmp,
 | |
| +			new ? (new + idx_new) : &tmp,
 | |
| +			sizeof(struct sched_domain_attr));
 | |
| +}
 | |
| +
 | |
| +/*
 | |
| + * Partition sched domains as specified by the 'ndoms_new'
 | |
| + * cpumasks in the array doms_new[] of cpumasks. This compares
 | |
| + * doms_new[] to the current sched domain partitioning, doms_cur[].
 | |
| + * It destroys each deleted domain and builds each new domain.
 | |
| + *
 | |
| + * 'doms_new' is an array of cpumask's of length 'ndoms_new'.
 | |
| + * The masks don't intersect (don't overlap.) We should setup one
 | |
| + * sched domain for each mask. CPUs not in any of the cpumasks will
 | |
| + * not be load balanced. If the same cpumask appears both in the
 | |
| + * current 'doms_cur' domains and in the new 'doms_new', we can leave
 | |
| + * it as it is.
 | |
| + *
 | |
| + * The passed in 'doms_new' should be kmalloc'd. This routine takes
 | |
| + * ownership of it and will kfree it when done with it. If the caller
 | |
| + * failed the kmalloc call, then it can pass in doms_new == NULL &&
 | |
| + * ndoms_new == 1, and partition_sched_domains() will fallback to
 | |
| + * the single partition 'fallback_doms', it also forces the domains
 | |
| + * to be rebuilt.
 | |
| + *
 | |
| + * If doms_new == NULL it will be replaced with cpu_online_mask.
 | |
| + * ndoms_new == 0 is a special case for destroying existing domains,
 | |
| + * and it will not create the default domain.
 | |
| + *
 | |
| + * Call with hotplug lock held
 | |
| + */
 | |
| +/* FIXME: Change to struct cpumask *doms_new[] */
 | |
| +void partition_sched_domains(int ndoms_new, struct cpumask *doms_new,
 | |
| +			     struct sched_domain_attr *dattr_new)
 | |
| +{
 | |
| +	int i, j, n;
 | |
| +	int new_topology;
 | |
| +
 | |
| +	mutex_lock(&sched_domains_mutex);
 | |
| +
 | |
| +	/* always unregister in case we don't destroy any domains */
 | |
| +	unregister_sched_domain_sysctl();
 | |
| +
 | |
| +	/* Let architecture update cpu core mappings. */
 | |
| +	new_topology = arch_update_cpu_topology();
 | |
| +
 | |
| +	n = doms_new ? ndoms_new : 0;
 | |
| +
 | |
| +	/* Destroy deleted domains */
 | |
| +	for (i = 0; i < ndoms_cur; i++) {
 | |
| +		for (j = 0; j < n && !new_topology; j++) {
 | |
| +			if (cpumask_equal(&doms_cur[i], &doms_new[j])
 | |
| +			    && dattrs_equal(dattr_cur, i, dattr_new, j))
 | |
| +				goto match1;
 | |
| +		}
 | |
| +		/* no match - a current sched domain not in new doms_new[] */
 | |
| +		detach_destroy_domains(doms_cur + i);
 | |
| +match1:
 | |
| +		;
 | |
| +	}
 | |
| +
 | |
| +	if (doms_new == NULL) {
 | |
| +		ndoms_cur = 0;
 | |
| +		doms_new = fallback_doms;
 | |
| +		cpumask_andnot(&doms_new[0], cpu_online_mask, cpu_isolated_map);
 | |
| +		WARN_ON_ONCE(dattr_new);
 | |
| +	}
 | |
| +
 | |
| +	/* Build new domains */
 | |
| +	for (i = 0; i < ndoms_new; i++) {
 | |
| +		for (j = 0; j < ndoms_cur && !new_topology; j++) {
 | |
| +			if (cpumask_equal(&doms_new[i], &doms_cur[j])
 | |
| +			    && dattrs_equal(dattr_new, i, dattr_cur, j))
 | |
| +				goto match2;
 | |
| +		}
 | |
| +		/* no match - add a new doms_new */
 | |
| +		__build_sched_domains(doms_new + i,
 | |
| +					dattr_new ? dattr_new + i : NULL);
 | |
| +match2:
 | |
| +		;
 | |
| +	}
 | |
| +
 | |
| +	/* Remember the new sched domains */
 | |
| +	if (doms_cur != fallback_doms)
 | |
| +		kfree(doms_cur);
 | |
| +	kfree(dattr_cur);	/* kfree(NULL) is safe */
 | |
| +	doms_cur = doms_new;
 | |
| +	dattr_cur = dattr_new;
 | |
| +	ndoms_cur = ndoms_new;
 | |
| +
 | |
| +	register_sched_domain_sysctl();
 | |
| +
 | |
| +	mutex_unlock(&sched_domains_mutex);
 | |
| +}
 | |
| +
 | |
| +#if defined(CONFIG_SCHED_MC) || defined(CONFIG_SCHED_SMT)
 | |
| +static void arch_reinit_sched_domains(void)
 | |
| +{
 | |
| +	get_online_cpus();
 | |
| +
 | |
| +	/* Destroy domains first to force the rebuild */
 | |
| +	partition_sched_domains(0, NULL, NULL);
 | |
| +
 | |
| +	rebuild_sched_domains();
 | |
| +	put_online_cpus();
 | |
| +}
 | |
| +
 | |
| +static ssize_t sched_power_savings_store(const char *buf, size_t count, int smt)
 | |
| +{
 | |
| +	unsigned int level = 0;
 | |
| +
 | |
| +	if (sscanf(buf, "%u", &level) != 1)
 | |
| +		return -EINVAL;
 | |
| +
 | |
| +	/*
 | |
| +	 * level is always be positive so don't check for
 | |
| +	 * level < POWERSAVINGS_BALANCE_NONE which is 0
 | |
| +	 * What happens on 0 or 1 byte write,
 | |
| +	 * need to check for count as well?
 | |
| +	 */
 | |
| +
 | |
| +	if (level >= MAX_POWERSAVINGS_BALANCE_LEVELS)
 | |
| +		return -EINVAL;
 | |
| +
 | |
| +	if (smt)
 | |
| +		sched_smt_power_savings = level;
 | |
| +	else
 | |
| +		sched_mc_power_savings = level;
 | |
| +
 | |
| +	arch_reinit_sched_domains();
 | |
| +
 | |
| +	return count;
 | |
| +}
 | |
| +
 | |
| +#ifdef CONFIG_SCHED_MC
 | |
| +static ssize_t sched_mc_power_savings_show(struct sysdev_class *class,
 | |
| +					   char *page)
 | |
| +{
 | |
| +	return sprintf(page, "%u\n", sched_mc_power_savings);
 | |
| +}
 | |
| +static ssize_t sched_mc_power_savings_store(struct sysdev_class *class,
 | |
| +					    const char *buf, size_t count)
 | |
| +{
 | |
| +	return sched_power_savings_store(buf, count, 0);
 | |
| +}
 | |
| +static SYSDEV_CLASS_ATTR(sched_mc_power_savings, 0644,
 | |
| +			 sched_mc_power_savings_show,
 | |
| +			 sched_mc_power_savings_store);
 | |
| +#endif
 | |
| +
 | |
| +#ifdef CONFIG_SCHED_SMT
 | |
| +static ssize_t sched_smt_power_savings_show(struct sysdev_class *dev,
 | |
| +					    char *page)
 | |
| +{
 | |
| +	return sprintf(page, "%u\n", sched_smt_power_savings);
 | |
| +}
 | |
| +static ssize_t sched_smt_power_savings_store(struct sysdev_class *dev,
 | |
| +					     const char *buf, size_t count)
 | |
| +{
 | |
| +	return sched_power_savings_store(buf, count, 1);
 | |
| +}
 | |
| +static SYSDEV_CLASS_ATTR(sched_smt_power_savings, 0644,
 | |
| +		   sched_smt_power_savings_show,
 | |
| +		   sched_smt_power_savings_store);
 | |
| +#endif
 | |
| +
 | |
| +int __init sched_create_sysfs_power_savings_entries(struct sysdev_class *cls)
 | |
| +{
 | |
| +	int err = 0;
 | |
| +
 | |
| +#ifdef CONFIG_SCHED_SMT
 | |
| +	if (smt_capable())
 | |
| +		err = sysfs_create_file(&cls->kset.kobj,
 | |
| +					&attr_sched_smt_power_savings.attr);
 | |
| +#endif
 | |
| +#ifdef CONFIG_SCHED_MC
 | |
| +	if (!err && mc_capable())
 | |
| +		err = sysfs_create_file(&cls->kset.kobj,
 | |
| +					&attr_sched_mc_power_savings.attr);
 | |
| +#endif
 | |
| +	return err;
 | |
| +}
 | |
| +#endif /* CONFIG_SCHED_MC || CONFIG_SCHED_SMT */
 | |
| +
 | |
| +#ifndef CONFIG_CPUSETS
 | |
| +/*
 | |
| + * Add online and remove offline CPUs from the scheduler domains.
 | |
| + * When cpusets are enabled they take over this function.
 | |
| + */
 | |
| +static int update_sched_domains(struct notifier_block *nfb,
 | |
| +				unsigned long action, void *hcpu)
 | |
| +{
 | |
| +	switch (action) {
 | |
| +	case CPU_ONLINE:
 | |
| +	case CPU_ONLINE_FROZEN:
 | |
| +	case CPU_DEAD:
 | |
| +	case CPU_DEAD_FROZEN:
 | |
| +		partition_sched_domains(1, NULL, NULL);
 | |
| +		return NOTIFY_OK;
 | |
| +
 | |
| +	default:
 | |
| +		return NOTIFY_DONE;
 | |
| +	}
 | |
| +}
 | |
| +#endif
 | |
| +
 | |
| +static int update_runtime(struct notifier_block *nfb,
 | |
| +				unsigned long action, void *hcpu)
 | |
| +{
 | |
| +	switch (action) {
 | |
| +	case CPU_DOWN_PREPARE:
 | |
| +	case CPU_DOWN_PREPARE_FROZEN:
 | |
| +		return NOTIFY_OK;
 | |
| +
 | |
| +	case CPU_DOWN_FAILED:
 | |
| +	case CPU_DOWN_FAILED_FROZEN:
 | |
| +	case CPU_ONLINE:
 | |
| +	case CPU_ONLINE_FROZEN:
 | |
| +		return NOTIFY_OK;
 | |
| +
 | |
| +	default:
 | |
| +		return NOTIFY_DONE;
 | |
| +	}
 | |
| +}
 | |
| +
 | |
| +void __init sched_init_smp(void)
 | |
| +{
 | |
| +	cpumask_var_t non_isolated_cpus;
 | |
| +
 | |
| +	alloc_cpumask_var(&non_isolated_cpus, GFP_KERNEL);
 | |
| +
 | |
| +#if defined(CONFIG_NUMA)
 | |
| +	sched_group_nodes_bycpu = kzalloc(nr_cpu_ids * sizeof(void **),
 | |
| +								GFP_KERNEL);
 | |
| +	BUG_ON(sched_group_nodes_bycpu == NULL);
 | |
| +#endif
 | |
| +	get_online_cpus();
 | |
| +	mutex_lock(&sched_domains_mutex);
 | |
| +	arch_init_sched_domains(cpu_online_mask);
 | |
| +	cpumask_andnot(non_isolated_cpus, cpu_possible_mask, cpu_isolated_map);
 | |
| +	if (cpumask_empty(non_isolated_cpus))
 | |
| +		cpumask_set_cpu(smp_processor_id(), non_isolated_cpus);
 | |
| +	mutex_unlock(&sched_domains_mutex);
 | |
| +	put_online_cpus();
 | |
| +
 | |
| +#ifndef CONFIG_CPUSETS
 | |
| +	/* XXX: Theoretical race here - CPU may be hotplugged now */
 | |
| +	hotcpu_notifier(update_sched_domains, 0);
 | |
| +#endif
 | |
| +
 | |
| +	/* RT runtime code needs to handle some hotplug events */
 | |
| +	hotcpu_notifier(update_runtime, 0);
 | |
| +
 | |
| +	/* Move init over to a non-isolated CPU */
 | |
| +	if (set_cpus_allowed_ptr(current, non_isolated_cpus) < 0)
 | |
| +		BUG();
 | |
| +	free_cpumask_var(non_isolated_cpus);
 | |
| +
 | |
| +	alloc_cpumask_var(&fallback_doms, GFP_KERNEL);
 | |
| +
 | |
| +	/*
 | |
| +	 * Assume that every added cpu gives us slightly less overall latency
 | |
| +	 * allowing us to increase the base rr_interval, but in a non linear
 | |
| +	 * fashion.
 | |
| +	 */
 | |
| +	rr_interval *= 1 + ilog2(num_online_cpus());
 | |
| +}
 | |
| +#else
 | |
| +void __init sched_init_smp(void)
 | |
| +{
 | |
| +}
 | |
| +#endif /* CONFIG_SMP */
 | |
| +
 | |
| +unsigned int sysctl_timer_migration = 1;
 | |
| +
 | |
| +int in_sched_functions(unsigned long addr)
 | |
| +{
 | |
| +	return in_lock_functions(addr) ||
 | |
| +		(addr >= (unsigned long)__sched_text_start
 | |
| +		&& addr < (unsigned long)__sched_text_end);
 | |
| +}
 | |
| +
 | |
| +void __init sched_init(void)
 | |
| +{
 | |
| +	int i;
 | |
| +	int highest_cpu = 0;
 | |
| +
 | |
| +	prio_ratios[0] = 100;
 | |
| +	for (i = 1 ; i < PRIO_RANGE ; i++)
 | |
| +		prio_ratios[i] = prio_ratios[i - 1] * 11 / 10;
 | |
| +
 | |
| +#ifdef CONFIG_SMP
 | |
| +	init_defrootdomain();
 | |
| +	cpus_clear(grq.cpu_idle_map);
 | |
| +#endif
 | |
| +	spin_lock_init(&grq.lock);
 | |
| +	for_each_possible_cpu(i) {
 | |
| +		struct rq *rq;
 | |
| +
 | |
| +		rq = cpu_rq(i);
 | |
| +		INIT_LIST_HEAD(&rq->queue);
 | |
| +		rq->rq_deadline = 0;
 | |
| +		rq->rq_prio = 0;
 | |
| +		rq->cpu = i;
 | |
| +		rq->user_pc = rq->nice_pc = rq->softirq_pc = rq->system_pc =
 | |
| +			      rq->iowait_pc = rq->idle_pc = 0;
 | |
| +#ifdef CONFIG_SMP
 | |
| +		rq->sd = NULL;
 | |
| +		rq->rd = NULL;
 | |
| +		rq->online = 0;
 | |
| +		INIT_LIST_HEAD(&rq->migration_queue);
 | |
| +		rq_attach_root(rq, &def_root_domain);
 | |
| +#endif
 | |
| +		atomic_set(&rq->nr_iowait, 0);
 | |
| +		highest_cpu = i;
 | |
| +	}
 | |
| +	grq.iso_ticks = grq.nr_running = grq.nr_uninterruptible = 0;
 | |
| +	for (i = 0; i < PRIO_LIMIT; i++)
 | |
| +		INIT_LIST_HEAD(grq.queue + i);
 | |
| +	bitmap_zero(grq.prio_bitmap, PRIO_LIMIT);
 | |
| +	/* delimiter for bitsearch */
 | |
| +	__set_bit(PRIO_LIMIT, grq.prio_bitmap);
 | |
| +
 | |
| +#ifdef CONFIG_SMP
 | |
| +	nr_cpu_ids = highest_cpu + 1;
 | |
| +#endif
 | |
| +
 | |
| +#ifdef CONFIG_PREEMPT_NOTIFIERS
 | |
| +	INIT_HLIST_HEAD(&init_task.preempt_notifiers);
 | |
| +#endif
 | |
| +
 | |
| +#ifdef CONFIG_RT_MUTEXES
 | |
| +	plist_head_init(&init_task.pi_waiters, &init_task.pi_lock);
 | |
| +#endif
 | |
| +
 | |
| +	/*
 | |
| +	 * The boot idle thread does lazy MMU switching as well:
 | |
| +	 */
 | |
| +	atomic_inc(&init_mm.mm_count);
 | |
| +	enter_lazy_tlb(&init_mm, current);
 | |
| +
 | |
| +	/*
 | |
| +	 * Make us the idle thread. Technically, schedule() should not be
 | |
| +	 * called from this thread, however somewhere below it might be,
 | |
| +	 * but because we are the idle thread, we just pick up running again
 | |
| +	 * when this runqueue becomes "idle".
 | |
| +	 */
 | |
| +	init_idle(current, smp_processor_id());
 | |
| +
 | |
| +	/* Allocate the nohz_cpu_mask if CONFIG_CPUMASK_OFFSTACK */
 | |
| +	alloc_cpumask_var(&nohz_cpu_mask, GFP_NOWAIT);
 | |
| +#ifdef CONFIG_SMP
 | |
| +#ifdef CONFIG_NO_HZ
 | |
| +	alloc_cpumask_var(&nohz.cpu_mask, GFP_NOWAIT);
 | |
| +	alloc_cpumask_var(&nohz.ilb_grp_nohz_mask, GFP_NOWAIT);
 | |
| +#endif
 | |
| +	alloc_cpumask_var(&cpu_isolated_map, GFP_NOWAIT);
 | |
| +#endif /* SMP */
 | |
| +	perf_counter_init();
 | |
| +}
 | |
| +
 | |
| +#ifdef CONFIG_DEBUG_SPINLOCK_SLEEP
 | |
| +void __might_sleep(char *file, int line)
 | |
| +{
 | |
| +#ifdef in_atomic
 | |
| +	static unsigned long prev_jiffy;	/* ratelimiting */
 | |
| +
 | |
| +	if ((in_atomic() || irqs_disabled()) &&
 | |
| +	    system_state == SYSTEM_RUNNING && !oops_in_progress) {
 | |
| +		if (time_before(jiffies, prev_jiffy + HZ) && prev_jiffy)
 | |
| +			return;
 | |
| +		prev_jiffy = jiffies;
 | |
| +		printk(KERN_ERR "BUG: sleeping function called from invalid"
 | |
| +				" context at %s:%d\n", file, line);
 | |
| +		printk("in_atomic():%d, irqs_disabled():%d\n",
 | |
| +			in_atomic(), irqs_disabled());
 | |
| +		debug_show_held_locks(current);
 | |
| +		if (irqs_disabled())
 | |
| +			print_irqtrace_events(current);
 | |
| +		dump_stack();
 | |
| +	}
 | |
| +#endif
 | |
| +}
 | |
| +EXPORT_SYMBOL(__might_sleep);
 | |
| +#endif
 | |
| +
 | |
| +#ifdef CONFIG_MAGIC_SYSRQ
 | |
| +void normalize_rt_tasks(void)
 | |
| +{
 | |
| +	struct task_struct *g, *p;
 | |
| +	unsigned long flags;
 | |
| +	struct rq *rq;
 | |
| +	int queued;
 | |
| +
 | |
| +	read_lock_irq(&tasklist_lock);
 | |
| +
 | |
| +	do_each_thread(g, p) {
 | |
| +		if (!rt_task(p) && !iso_task(p))
 | |
| +			continue;
 | |
| +
 | |
| +		spin_lock_irqsave(&p->pi_lock, flags);
 | |
| +		rq = __task_grq_lock(p);
 | |
| +		update_rq_clock(rq);
 | |
| +
 | |
| +		queued = task_queued_only(p);
 | |
| +		if (queued)
 | |
| +			dequeue_task(p);
 | |
| +		__setscheduler(p, SCHED_NORMAL, 0);
 | |
| +		if (task_running(p))
 | |
| +			resched_task(p);
 | |
| +		if (queued) {
 | |
| +			enqueue_task(p);
 | |
| +			try_preempt(p);
 | |
| +		}
 | |
| +
 | |
| +		__task_grq_unlock();
 | |
| +		spin_unlock_irqrestore(&p->pi_lock, flags);
 | |
| +	} while_each_thread(g, p);
 | |
| +
 | |
| +	read_unlock_irq(&tasklist_lock);
 | |
| +}
 | |
| +#endif /* CONFIG_MAGIC_SYSRQ */
 | |
| +
 | |
| +#ifdef CONFIG_IA64
 | |
| +/*
 | |
| + * These functions are only useful for the IA64 MCA handling.
 | |
| + *
 | |
| + * They can only be called when the whole system has been
 | |
| + * stopped - every CPU needs to be quiescent, and no scheduling
 | |
| + * activity can take place. Using them for anything else would
 | |
| + * be a serious bug, and as a result, they aren't even visible
 | |
| + * under any other configuration.
 | |
| + */
 | |
| +
 | |
| +/**
 | |
| + * curr_task - return the current task for a given cpu.
 | |
| + * @cpu: the processor in question.
 | |
| + *
 | |
| + * ONLY VALID WHEN THE WHOLE SYSTEM IS STOPPED!
 | |
| + */
 | |
| +struct task_struct *curr_task(int cpu)
 | |
| +{
 | |
| +	return cpu_curr(cpu);
 | |
| +}
 | |
| +
 | |
| +/**
 | |
| + * set_curr_task - set the current task for a given cpu.
 | |
| + * @cpu: the processor in question.
 | |
| + * @p: the task pointer to set.
 | |
| + *
 | |
| + * Description: This function must only be used when non-maskable interrupts
 | |
| + * are serviced on a separate stack.  It allows the architecture to switch the
 | |
| + * notion of the current task on a cpu in a non-blocking manner.  This function
 | |
| + * must be called with all CPU's synchronized, and interrupts disabled, the
 | |
| + * and caller must save the original value of the current task (see
 | |
| + * curr_task() above) and restore that value before reenabling interrupts and
 | |
| + * re-starting the system.
 | |
| + *
 | |
| + * ONLY VALID WHEN THE WHOLE SYSTEM IS STOPPED!
 | |
| + */
 | |
| +void set_curr_task(int cpu, struct task_struct *p)
 | |
| +{
 | |
| +	cpu_curr(cpu) = p;
 | |
| +}
 | |
| +
 | |
| +#endif
 | |
| +
 | |
| +/*
 | |
| + * Use precise platform statistics if available:
 | |
| + */
 | |
| +#ifdef CONFIG_VIRT_CPU_ACCOUNTING
 | |
| +cputime_t task_utime(struct task_struct *p)
 | |
| +{
 | |
| +	return p->utime;
 | |
| +}
 | |
| +
 | |
| +cputime_t task_stime(struct task_struct *p)
 | |
| +{
 | |
| +	return p->stime;
 | |
| +}
 | |
| +#else
 | |
| +cputime_t task_utime(struct task_struct *p)
 | |
| +{
 | |
| +	clock_t utime = cputime_to_clock_t(p->utime),
 | |
| +		total = utime + cputime_to_clock_t(p->stime);
 | |
| +	u64 temp;
 | |
| +
 | |
| +	temp = (u64)nsec_to_clock_t(p->se.sum_exec_runtime);
 | |
| +
 | |
| +	if (total) {
 | |
| +		temp *= utime;
 | |
| +		do_div(temp, total);
 | |
| +	}
 | |
| +	utime = (clock_t)temp;
 | |
| +
 | |
| +	p->prev_utime = max(p->prev_utime, clock_t_to_cputime(utime));
 | |
| +	return p->prev_utime;
 | |
| +}
 | |
| +
 | |
| +cputime_t task_stime(struct task_struct *p)
 | |
| +{
 | |
| +	clock_t stime;
 | |
| +
 | |
| +	stime = nsec_to_clock_t(p->se.sum_exec_runtime) -
 | |
| +			cputime_to_clock_t(task_utime(p));
 | |
| +
 | |
| +	if (stime >= 0)
 | |
| +		p->prev_stime = max(p->prev_stime, clock_t_to_cputime(stime));
 | |
| +
 | |
| +	return p->prev_stime;
 | |
| +}
 | |
| +#endif
 | |
| +
 | |
| +inline cputime_t task_gtime(struct task_struct *p)
 | |
| +{
 | |
| +	return p->gtime;
 | |
| +}
 | |
| +
 | |
| +void __cpuinit init_idle_bootup_task(struct task_struct *idle)
 | |
| +{}
 | |
| +
 | |
| +#ifdef CONFIG_SCHED_DEBUG
 | |
| +void proc_sched_show_task(struct task_struct *p, struct seq_file *m)
 | |
| +{}
 | |
| +
 | |
| +void proc_sched_set_task(struct task_struct *p)
 | |
| +{}
 | |
| +#endif
 | |
| --- a/kernel/sysctl.c
 | |
| +++ b/kernel/sysctl.c
 | |
| @@ -83,6 +83,8 @@ extern int percpu_pagelist_fraction;
 | |
|  extern int compat_log;
 | |
|  extern int latencytop_enabled;
 | |
|  extern int sysctl_nr_open_min, sysctl_nr_open_max;
 | |
| +extern int rr_interval;
 | |
| +extern int sched_iso_cpu;
 | |
|  #ifndef CONFIG_MMU
 | |
|  extern int sysctl_nr_trim_pages;
 | |
|  #endif
 | |
| @@ -100,7 +102,8 @@ static int zero;
 | |
|  static int __maybe_unused one = 1;
 | |
|  static int __maybe_unused two = 2;
 | |
|  static unsigned long one_ul = 1;
 | |
| -static int one_hundred = 100;
 | |
| +static int __read_mostly one_hundred = 100;
 | |
| +static int __maybe_unused __read_mostly five_thousand = 5000;
 | |
|  
 | |
|  /* this is needed for the proc_doulongvec_minmax of vm_dirty_bytes */
 | |
|  static unsigned long dirty_bytes_min = 2 * PAGE_SIZE;
 | |
| @@ -234,7 +237,7 @@ static struct ctl_table root_table[] = {
 | |
|  	{ .ctl_name = 0 }
 | |
|  };
 | |
|  
 | |
| -#ifdef CONFIG_SCHED_DEBUG
 | |
| +#if defined(CONFIG_SCHED_DEBUG) && defined(CONFIG_SCHED_CFS)
 | |
|  static int min_sched_granularity_ns = 100000;		/* 100 usecs */
 | |
|  static int max_sched_granularity_ns = NSEC_PER_SEC;	/* 1 second */
 | |
|  static int min_wakeup_granularity_ns;			/* 0 usecs */
 | |
| @@ -242,7 +245,7 @@ static int max_wakeup_granularity_ns = N
 | |
|  #endif
 | |
|  
 | |
|  static struct ctl_table kern_table[] = {
 | |
| -#ifdef CONFIG_SCHED_DEBUG
 | |
| +#if defined(CONFIG_SCHED_DEBUG) && defined(CONFIG_SCHED_CFS)
 | |
|  	{
 | |
|  		.ctl_name	= CTL_UNNUMBERED,
 | |
|  		.procname	= "sched_min_granularity_ns",
 | |
| @@ -327,6 +330,7 @@ static struct ctl_table kern_table[] = {
 | |
|  		.proc_handler	= &proc_dointvec,
 | |
|  	},
 | |
|  #endif
 | |
| +#ifdef CONFIG_SCHED_CFS
 | |
|  	{
 | |
|  		.ctl_name	= CTL_UNNUMBERED,
 | |
|  		.procname	= "sched_rt_period_us",
 | |
| @@ -351,6 +355,7 @@ static struct ctl_table kern_table[] = {
 | |
|  		.mode		= 0644,
 | |
|  		.proc_handler	= &proc_dointvec,
 | |
|  	},
 | |
| +#endif
 | |
|  #ifdef CONFIG_PROVE_LOCKING
 | |
|  	{
 | |
|  		.ctl_name	= CTL_UNNUMBERED,
 | |
| @@ -756,6 +761,30 @@ static struct ctl_table kern_table[] = {
 | |
|  		.proc_handler	= &proc_dointvec,
 | |
|  	},
 | |
|  #endif
 | |
| +#ifdef CONFIG_SCHED_BFS
 | |
| +	{
 | |
| +		.ctl_name	= CTL_UNNUMBERED,
 | |
| +		.procname	= "rr_interval",
 | |
| +		.data		= &rr_interval,
 | |
| +		.maxlen		= sizeof (int),
 | |
| +		.mode		= 0644,
 | |
| +		.proc_handler	= &proc_dointvec_minmax,
 | |
| +		.strategy	= &sysctl_intvec,
 | |
| +		.extra1		= &one,
 | |
| +		.extra2		= &five_thousand,
 | |
| +	},
 | |
| +	{
 | |
| +		.ctl_name	= CTL_UNNUMBERED,
 | |
| +		.procname	= "iso_cpu",
 | |
| +		.data		= &sched_iso_cpu,
 | |
| +		.maxlen		= sizeof (int),
 | |
| +		.mode		= 0644,
 | |
| +		.proc_handler	= &proc_dointvec_minmax,
 | |
| +		.strategy	= &sysctl_intvec,
 | |
| +		.extra1		= &zero,
 | |
| +		.extra2		= &one_hundred,
 | |
| +	},
 | |
| +#endif
 | |
|  #if defined(CONFIG_S390) && defined(CONFIG_SMP)
 | |
|  	{
 | |
|  		.ctl_name	= KERN_SPIN_RETRY,
 | |
| --- a/kernel/workqueue.c
 | |
| +++ b/kernel/workqueue.c
 | |
| @@ -320,7 +320,9 @@ static int worker_thread(void *__cwq)
 | |
|  	if (cwq->wq->freezeable)
 | |
|  		set_freezable();
 | |
|  
 | |
| +#ifdef CONFIG_SCHED_CFS
 | |
|  	set_user_nice(current, -5);
 | |
| +#endif
 | |
|  
 | |
|  	for (;;) {
 | |
|  		prepare_to_wait(&cwq->more_work, &wait, TASK_INTERRUPTIBLE);
 | |
| --- /dev/null
 | |
| +++ b/include/linux/perf_counter.h
 | |
| @@ -0,0 +1,2 @@
 | |
| +#define perf_counter_init() do {} while(0)
 | |
| +#define perf_counter_task_sched_in(...) do {} while(0)
 | |
| --- /dev/null
 | |
| +++ b/include/trace/events/sched.h
 | |
| @@ -0,0 +1 @@
 | |
| +#include <trace/sched.h>
 |