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	also refresh generic patches for 3.14, 3.18, 3.19 and 4.0 targets might need a minor refresh as well, however, it looks like everything still applies cleanly with occasional small offsets. Signed-off-by: Daniel Golle <daniel@makrotopia.org> SVN-Revision: 44876
		
			
				
	
	
		
			346 lines
		
	
	
		
			10 KiB
		
	
	
	
		
			Diff
		
	
	
	
	
	
			
		
		
	
	
			346 lines
		
	
	
		
			10 KiB
		
	
	
	
		
			Diff
		
	
	
	
	
	
| From: Alexander Duyck <alexander.h.duyck@redhat.com>
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| Date: Wed, 31 Dec 2014 10:56:31 -0800
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| Subject: [PATCH] fib_trie: Move resize to after inflate/halve
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| 
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| This change consists of a cut/paste of resize to behind inflate and halve
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| so that I could remove the two function prototypes.
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| 
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| Signed-off-by: Alexander Duyck <alexander.h.duyck@redhat.com>
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| Signed-off-by: David S. Miller <davem@davemloft.net>
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| ---
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| 
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| --- a/net/ipv4/fib_trie.c
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| +++ b/net/ipv4/fib_trie.c
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| @@ -149,8 +149,6 @@ struct trie {
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|  static void tnode_put_child_reorg(struct tnode *tn, unsigned long i,
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|  				  struct tnode *n, int wasfull);
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|  static struct tnode *resize(struct trie *t, struct tnode *tn);
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| -static struct tnode *inflate(struct trie *t, struct tnode *tn);
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| -static struct tnode *halve(struct trie *t, struct tnode *tn);
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|  /* tnodes to free after resize(); protected by RTNL */
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|  static struct callback_head *tnode_free_head;
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|  static size_t tnode_free_size;
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| @@ -447,161 +445,6 @@ static void put_child_root(struct tnode
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|  		rcu_assign_pointer(t->trie, n);
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|  }
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|  
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| -#define MAX_WORK 10
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| -static struct tnode *resize(struct trie *t, struct tnode *tn)
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| -{
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| -	struct tnode *old_tn, *n = NULL;
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| -	int inflate_threshold_use;
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| -	int halve_threshold_use;
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| -	int max_work;
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| -
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| -	if (!tn)
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| -		return NULL;
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| -
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| -	pr_debug("In tnode_resize %p inflate_threshold=%d threshold=%d\n",
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| -		 tn, inflate_threshold, halve_threshold);
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| -
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| -	/* No children */
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| -	if (tn->empty_children > (tnode_child_length(tn) - 1))
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| -		goto no_children;
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| -
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| -	/* One child */
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| -	if (tn->empty_children == (tnode_child_length(tn) - 1))
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| -		goto one_child;
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| -	/*
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| -	 * Double as long as the resulting node has a number of
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| -	 * nonempty nodes that are above the threshold.
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| -	 */
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| -
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| -	/*
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| -	 * From "Implementing a dynamic compressed trie" by Stefan Nilsson of
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| -	 * the Helsinki University of Technology and Matti Tikkanen of Nokia
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| -	 * Telecommunications, page 6:
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| -	 * "A node is doubled if the ratio of non-empty children to all
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| -	 * children in the *doubled* node is at least 'high'."
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| -	 *
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| -	 * 'high' in this instance is the variable 'inflate_threshold'. It
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| -	 * is expressed as a percentage, so we multiply it with
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| -	 * tnode_child_length() and instead of multiplying by 2 (since the
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| -	 * child array will be doubled by inflate()) and multiplying
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| -	 * the left-hand side by 100 (to handle the percentage thing) we
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| -	 * multiply the left-hand side by 50.
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| -	 *
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| -	 * The left-hand side may look a bit weird: tnode_child_length(tn)
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| -	 * - tn->empty_children is of course the number of non-null children
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| -	 * in the current node. tn->full_children is the number of "full"
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| -	 * children, that is non-null tnodes with a skip value of 0.
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| -	 * All of those will be doubled in the resulting inflated tnode, so
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| -	 * we just count them one extra time here.
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| -	 *
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| -	 * A clearer way to write this would be:
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| -	 *
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| -	 * to_be_doubled = tn->full_children;
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| -	 * not_to_be_doubled = tnode_child_length(tn) - tn->empty_children -
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| -	 *     tn->full_children;
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| -	 *
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| -	 * new_child_length = tnode_child_length(tn) * 2;
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| -	 *
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| -	 * new_fill_factor = 100 * (not_to_be_doubled + 2*to_be_doubled) /
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| -	 *      new_child_length;
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| -	 * if (new_fill_factor >= inflate_threshold)
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| -	 *
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| -	 * ...and so on, tho it would mess up the while () loop.
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| -	 *
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| -	 * anyway,
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| -	 * 100 * (not_to_be_doubled + 2*to_be_doubled) / new_child_length >=
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| -	 *      inflate_threshold
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| -	 *
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| -	 * avoid a division:
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| -	 * 100 * (not_to_be_doubled + 2*to_be_doubled) >=
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| -	 *      inflate_threshold * new_child_length
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| -	 *
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| -	 * expand not_to_be_doubled and to_be_doubled, and shorten:
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| -	 * 100 * (tnode_child_length(tn) - tn->empty_children +
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| -	 *    tn->full_children) >= inflate_threshold * new_child_length
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| -	 *
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| -	 * expand new_child_length:
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| -	 * 100 * (tnode_child_length(tn) - tn->empty_children +
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| -	 *    tn->full_children) >=
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| -	 *      inflate_threshold * tnode_child_length(tn) * 2
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| -	 *
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| -	 * shorten again:
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| -	 * 50 * (tn->full_children + tnode_child_length(tn) -
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| -	 *    tn->empty_children) >= inflate_threshold *
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| -	 *    tnode_child_length(tn)
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| -	 *
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| -	 */
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| -
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| -	/* Keep root node larger  */
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| -
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| -	if (!node_parent(tn)) {
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| -		inflate_threshold_use = inflate_threshold_root;
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| -		halve_threshold_use = halve_threshold_root;
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| -	} else {
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| -		inflate_threshold_use = inflate_threshold;
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| -		halve_threshold_use = halve_threshold;
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| -	}
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| -
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| -	max_work = MAX_WORK;
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| -	while ((tn->full_children > 0 &&  max_work-- &&
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| -		50 * (tn->full_children + tnode_child_length(tn)
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| -		      - tn->empty_children)
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| -		>= inflate_threshold_use * tnode_child_length(tn))) {
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| -
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| -		old_tn = tn;
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| -		tn = inflate(t, tn);
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| -
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| -		if (IS_ERR(tn)) {
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| -			tn = old_tn;
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| -#ifdef CONFIG_IP_FIB_TRIE_STATS
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| -			this_cpu_inc(t->stats->resize_node_skipped);
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| -#endif
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| -			break;
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| -		}
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| -	}
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| -
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| -	/* Return if at least one inflate is run */
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| -	if (max_work != MAX_WORK)
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| -		return tn;
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| -
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| -	/*
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| -	 * Halve as long as the number of empty children in this
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| -	 * node is above threshold.
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| -	 */
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| -
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| -	max_work = MAX_WORK;
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| -	while (tn->bits > 1 &&  max_work-- &&
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| -	       100 * (tnode_child_length(tn) - tn->empty_children) <
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| -	       halve_threshold_use * tnode_child_length(tn)) {
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| -
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| -		old_tn = tn;
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| -		tn = halve(t, tn);
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| -		if (IS_ERR(tn)) {
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| -			tn = old_tn;
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| -#ifdef CONFIG_IP_FIB_TRIE_STATS
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| -			this_cpu_inc(t->stats->resize_node_skipped);
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| -#endif
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| -			break;
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| -		}
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| -	}
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| -
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| -
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| -	/* Only one child remains */
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| -	if (tn->empty_children == (tnode_child_length(tn) - 1)) {
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| -		unsigned long i;
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| -one_child:
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| -		for (i = tnode_child_length(tn); !n && i;)
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| -			n = tnode_get_child(tn, --i);
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| -no_children:
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| -		/* compress one level */
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| -		node_set_parent(n, NULL);
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| -		tnode_free_safe(tn);
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| -		return n;
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| -	}
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| -	return tn;
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| -}
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| -
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| -
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|  static void tnode_clean_free(struct tnode *tn)
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|  {
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|  	struct tnode *tofree;
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| @@ -804,6 +647,160 @@ nomem:
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|  	return ERR_PTR(-ENOMEM);
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|  }
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|  
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| +#define MAX_WORK 10
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| +static struct tnode *resize(struct trie *t, struct tnode *tn)
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| +{
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| +	struct tnode *old_tn, *n = NULL;
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| +	int inflate_threshold_use;
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| +	int halve_threshold_use;
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| +	int max_work;
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| +
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| +	if (!tn)
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| +		return NULL;
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| +
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| +	pr_debug("In tnode_resize %p inflate_threshold=%d threshold=%d\n",
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| +		 tn, inflate_threshold, halve_threshold);
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| +
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| +	/* No children */
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| +	if (tn->empty_children > (tnode_child_length(tn) - 1))
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| +		goto no_children;
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| +
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| +	/* One child */
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| +	if (tn->empty_children == (tnode_child_length(tn) - 1))
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| +		goto one_child;
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| +	/*
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| +	 * Double as long as the resulting node has a number of
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| +	 * nonempty nodes that are above the threshold.
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| +	 */
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| +
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| +	/*
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| +	 * From "Implementing a dynamic compressed trie" by Stefan Nilsson of
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| +	 * the Helsinki University of Technology and Matti Tikkanen of Nokia
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| +	 * Telecommunications, page 6:
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| +	 * "A node is doubled if the ratio of non-empty children to all
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| +	 * children in the *doubled* node is at least 'high'."
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| +	 *
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| +	 * 'high' in this instance is the variable 'inflate_threshold'. It
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| +	 * is expressed as a percentage, so we multiply it with
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| +	 * tnode_child_length() and instead of multiplying by 2 (since the
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| +	 * child array will be doubled by inflate()) and multiplying
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| +	 * the left-hand side by 100 (to handle the percentage thing) we
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| +	 * multiply the left-hand side by 50.
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| +	 *
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| +	 * The left-hand side may look a bit weird: tnode_child_length(tn)
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| +	 * - tn->empty_children is of course the number of non-null children
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| +	 * in the current node. tn->full_children is the number of "full"
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| +	 * children, that is non-null tnodes with a skip value of 0.
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| +	 * All of those will be doubled in the resulting inflated tnode, so
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| +	 * we just count them one extra time here.
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| +	 *
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| +	 * A clearer way to write this would be:
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| +	 *
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| +	 * to_be_doubled = tn->full_children;
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| +	 * not_to_be_doubled = tnode_child_length(tn) - tn->empty_children -
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| +	 *     tn->full_children;
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| +	 *
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| +	 * new_child_length = tnode_child_length(tn) * 2;
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| +	 *
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| +	 * new_fill_factor = 100 * (not_to_be_doubled + 2*to_be_doubled) /
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| +	 *      new_child_length;
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| +	 * if (new_fill_factor >= inflate_threshold)
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| +	 *
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| +	 * ...and so on, tho it would mess up the while () loop.
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| +	 *
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| +	 * anyway,
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| +	 * 100 * (not_to_be_doubled + 2*to_be_doubled) / new_child_length >=
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| +	 *      inflate_threshold
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| +	 *
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| +	 * avoid a division:
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| +	 * 100 * (not_to_be_doubled + 2*to_be_doubled) >=
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| +	 *      inflate_threshold * new_child_length
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| +	 *
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| +	 * expand not_to_be_doubled and to_be_doubled, and shorten:
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| +	 * 100 * (tnode_child_length(tn) - tn->empty_children +
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| +	 *    tn->full_children) >= inflate_threshold * new_child_length
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| +	 *
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| +	 * expand new_child_length:
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| +	 * 100 * (tnode_child_length(tn) - tn->empty_children +
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| +	 *    tn->full_children) >=
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| +	 *      inflate_threshold * tnode_child_length(tn) * 2
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| +	 *
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| +	 * shorten again:
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| +	 * 50 * (tn->full_children + tnode_child_length(tn) -
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| +	 *    tn->empty_children) >= inflate_threshold *
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| +	 *    tnode_child_length(tn)
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| +	 *
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| +	 */
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| +
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| +	/* Keep root node larger  */
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| +
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| +	if (!node_parent(tn)) {
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| +		inflate_threshold_use = inflate_threshold_root;
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| +		halve_threshold_use = halve_threshold_root;
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| +	} else {
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| +		inflate_threshold_use = inflate_threshold;
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| +		halve_threshold_use = halve_threshold;
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| +	}
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| +
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| +	max_work = MAX_WORK;
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| +	while ((tn->full_children > 0 &&  max_work-- &&
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| +		50 * (tn->full_children + tnode_child_length(tn)
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| +		      - tn->empty_children)
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| +		>= inflate_threshold_use * tnode_child_length(tn))) {
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| +
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| +		old_tn = tn;
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| +		tn = inflate(t, tn);
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| +
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| +		if (IS_ERR(tn)) {
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| +			tn = old_tn;
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| +#ifdef CONFIG_IP_FIB_TRIE_STATS
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| +			this_cpu_inc(t->stats->resize_node_skipped);
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| +#endif
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| +			break;
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| +		}
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| +	}
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| +
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| +	/* Return if at least one inflate is run */
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| +	if (max_work != MAX_WORK)
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| +		return tn;
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| +
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| +	/*
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| +	 * Halve as long as the number of empty children in this
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| +	 * node is above threshold.
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| +	 */
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| +
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| +	max_work = MAX_WORK;
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| +	while (tn->bits > 1 &&  max_work-- &&
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| +	       100 * (tnode_child_length(tn) - tn->empty_children) <
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| +	       halve_threshold_use * tnode_child_length(tn)) {
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| +
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| +		old_tn = tn;
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| +		tn = halve(t, tn);
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| +		if (IS_ERR(tn)) {
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| +			tn = old_tn;
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| +#ifdef CONFIG_IP_FIB_TRIE_STATS
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| +			this_cpu_inc(t->stats->resize_node_skipped);
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| +#endif
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| +			break;
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| +		}
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| +	}
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| +
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| +
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| +	/* Only one child remains */
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| +	if (tn->empty_children == (tnode_child_length(tn) - 1)) {
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| +		unsigned long i;
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| +one_child:
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| +		for (i = tnode_child_length(tn); !n && i;)
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| +			n = tnode_get_child(tn, --i);
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| +no_children:
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| +		/* compress one level */
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| +		node_set_parent(n, NULL);
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| +		tnode_free_safe(tn);
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| +		return n;
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| +	}
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| +	return tn;
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| +}
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| +
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|  /* readside must use rcu_read_lock currently dump routines
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|   via get_fa_head and dump */
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|  
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