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Commit 3ded175a authored by Christoph Lameter's avatar Christoph Lameter Committed by Linus Torvalds
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[PATCH] slab: add transfer_objects() function 



slabr_objects() can be used to transfer objects between various object
caches of the slab allocator.  It is currently only used during
__cache_alloc() to retrieve elements from the shared array.  We will be
using it soon to transfer elements from the alien caches to the remote
shared array.

Signed-off-by: default avatarChristoph Lameter <clameter@sgi.com>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent c5e3b83e

mm/slab.c

+28 −14
Original line number Diff line number Diff line
@@ -898,6 +898,30 @@ static struct array_cache *alloc_arraycache(int node, int entries, 
	return nc;

}



/*

 * Transfer objects in one arraycache to another.

 * Locking must be handled by the caller.

 *

 * Return the number of entries transferred.

 */

static int transfer_objects(struct array_cache *to,

		struct array_cache *from, unsigned int max)

{

	/* Figure out how many entries to transfer */

	int nr = min(min(from->avail, max), to->limit - to->avail);



	if (!nr)

		return 0;



	memcpy(to->entry + to->avail, from->entry + from->avail -nr,

			sizeof(void *) *nr);



	from->avail -= nr;

	to->avail += nr;

	to->touched = 1;

	return nr;

}



#ifdef CONFIG_NUMA

static void *__cache_alloc_node(struct kmem_cache *, gfp_t, int);

static void *alternate_node_alloc(struct kmem_cache *, gfp_t);
@@ -2680,20 +2704,10 @@ static void *cache_alloc_refill(struct kmem_cache *cachep, gfp_t flags) 
	BUG_ON(ac->avail > 0 || !l3);

	spin_lock(&l3->list_lock);



	if (l3->shared) {

		struct array_cache *shared_array = l3->shared;

		if (shared_array->avail) {

			if (batchcount > shared_array->avail)

				batchcount = shared_array->avail;

			shared_array->avail -= batchcount;

			ac->avail = batchcount;

			memcpy(ac->entry,

			       &(shared_array->entry[shared_array->avail]),

			       sizeof(void *) * batchcount);

			shared_array->touched = 1;

	/* See if we can refill from the shared array */

	if (l3->shared && transfer_objects(ac, l3->shared, batchcount))

		goto alloc_done;

		}

	}



	while (batchcount > 0) {

		struct list_head *entry;

		struct slab *slabp;