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slub: move kmem_cache_node into it's own cacheline 

This patch is meant to improve the performance of SLUB by moving the local
kmem_cache_node lock into it's own cacheline separate from kmem_cache.
This is accomplished by simply removing the local_node when NUMA is enabled.

On my system with 2 nodes I saw around a 5% performance increase w/
hackbench times dropping from 6.2 seconds to 5.9 seconds on average.  I
suspect the performance gain would increase as the number of nodes
increases, but I do not have the data to currently back that up.

Bugzilla-Reference: http://bugzilla.kernel.org/show_bug.cgi?id=15713
Cc: <stable@kernel.org>
Reported-by: Alex Shi <alex.shi@intel.com>
Tested-by: Alex Shi <alex.shi@intel.com>
Acked-by: Yanmin Zhang <yanmin_zhang@linux.intel.com>
Acked-by: Christoph Lameter <cl@linux-foundation.org>
Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
This commit is contained in:
Alexander Duyck 2010-05-21 14:41:35 -07:00 committed by Pekka Enberg
parent 7e125f7b9c
commit 73367bd8ee
2 changed files with 15 additions and 29 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

9
include/linux/slub_def.h
View File

@ -75,12 +75,6 @@ struct kmem_cache {
int offset; /* Free pointer offset. */
struct kmem_cache_order_objects oo;
/*
* Avoid an extra cache line for UP, SMP and for the node local to
* struct kmem_cache.
*/
struct kmem_cache_node local_node;
/* Allocation and freeing of slabs */
struct kmem_cache_order_objects max;
struct kmem_cache_order_objects min;
@ -102,6 +96,9 @@ struct kmem_cache {
*/
int remote_node_defrag_ratio;
struct kmem_cache_node *node[MAX_NUMNODES];
#else
/* Avoid an extra cache line for UP */
struct kmem_cache_node local_node;
#endif
};

35
mm/slub.c
View File

@ -2133,7 +2133,7 @@ static void free_kmem_cache_nodes(struct kmem_cache *s)
for_each_node_state(node, N_NORMAL_MEMORY) {
struct kmem_cache_node *n = s->node[node];
if (n && n != &s->local_node)
if (n)
kmem_cache_free(kmalloc_caches, n);
s->node[node] = NULL;
}
@ -2142,33 +2142,22 @@ static void free_kmem_cache_nodes(struct kmem_cache *s)
static int init_kmem_cache_nodes(struct kmem_cache *s, gfp_t gfpflags)
{
int node;
int local_node;
if (slab_state >= UP && (s < kmalloc_caches ||
s >= kmalloc_caches + KMALLOC_CACHES))
local_node = page_to_nid(virt_to_page(s));
else
local_node = 0;
for_each_node_state(node, N_NORMAL_MEMORY) {
struct kmem_cache_node *n;
if (local_node == node)
n = &s->local_node;
else {
if (slab_state == DOWN) {
early_kmem_cache_node_alloc(gfpflags, node);
continue;
}
n = kmem_cache_alloc_node(kmalloc_caches,
gfpflags, node);
if (!n) {
free_kmem_cache_nodes(s);
return 0;
}
if (slab_state == DOWN) {
early_kmem_cache_node_alloc(gfpflags, node);
continue;
}
n = kmem_cache_alloc_node(kmalloc_caches,
gfpflags, node);
if (!n) {
free_kmem_cache_nodes(s);
return 0;
}
s->node[node] = n;
init_kmem_cache_node(n, s);
}