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Commit 1293d5c5 authored by Matthew Wilcox's avatar Matthew Wilcox
Browse files

radix-tree: Chain preallocated nodes through ->parent 



Chaining through the ->private_data member means we have to zero
->private_data after removing preallocated nodes from the list.
We're about to initialise ->parent anyway, so we can avoid zeroing it.

Signed-off-by: default avatarMatthew Wilcox <mawilcox@microsoft.com>
parent 73bc029b

lib/radix-tree.c

+4 −5
Original line number Diff line number Diff line
@@ -82,7 +82,7 @@ static struct kmem_cache *radix_tree_node_cachep; 
 */

struct radix_tree_preload {

	unsigned nr;

	/* nodes->private_data points to next preallocated node */

	/* nodes->parent points to next preallocated node */

	struct radix_tree_node *nodes;

};

static DEFINE_PER_CPU(struct radix_tree_preload, radix_tree_preloads) = { 0, };
@@ -405,8 +405,7 @@ radix_tree_node_alloc(gfp_t gfp_mask, struct radix_tree_node *parent, 
		rtp = this_cpu_ptr(&radix_tree_preloads);

		if (rtp->nr) {

			ret = rtp->nodes;

			rtp->nodes = ret->private_data;

			ret->private_data = NULL;

			rtp->nodes = ret->parent;

			rtp->nr--;

		}

		/*
@@ -483,7 +482,7 @@ static int __radix_tree_preload(gfp_t gfp_mask, unsigned nr) 
		preempt_disable();

		rtp = this_cpu_ptr(&radix_tree_preloads);

		if (rtp->nr < nr) {

			node->private_data = rtp->nodes;

			node->parent = rtp->nodes;

			rtp->nodes = node;

			rtp->nr++;

		} else {
@@ -2260,7 +2259,7 @@ static int radix_tree_cpu_dead(unsigned int cpu) 
	rtp = &per_cpu(radix_tree_preloads, cpu);

	while (rtp->nr) {

		node = rtp->nodes;

		rtp->nodes = node->private_data;

		rtp->nodes = node->parent;

		kmem_cache_free(radix_tree_node_cachep, node);

		rtp->nr--;

	}

tools/testing/radix-tree/linux.c

+3 −3
Original line number Diff line number Diff line
@@ -35,9 +35,9 @@ void *kmem_cache_alloc(struct kmem_cache *cachep, int flags) 
	if (cachep->nr_objs) {

		cachep->nr_objs--;

		node = cachep->objs;

		cachep->objs = node->private_data;

		cachep->objs = node->parent;

		pthread_mutex_unlock(&cachep->lock);

		node->private_data = NULL;

		node->parent = NULL;

	} else {

		pthread_mutex_unlock(&cachep->lock);

		node = malloc(cachep->size);
@@ -64,7 +64,7 @@ void kmem_cache_free(struct kmem_cache *cachep, void *objp) 
	} else {

		struct radix_tree_node *node = objp;

		cachep->nr_objs++;

		node->private_data = cachep->objs;

		node->parent = cachep->objs;

		cachep->objs = node;

	}

	pthread_mutex_unlock(&cachep->lock);