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slab: skip calling cache_free_alien() when the platform is not numa capable

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Skip calling cache_free_alien() when the platform is not numa capable.
This will avoid cache misses that happen while accessing slabp (which is
per page memory reference) to get nodeid.  Instead use a global variable to
skip the call, which is mostly likely to be present in the cache.

This gives a 0.8% performance boost with the database oltp workload on a
quad-core SMP platform and by any means the number is not small :)

Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Acked-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Siddha, Suresh B
2007-08-22 14:01:49 -07:00
committed by Linus Torvalds
parent 32d219854d
commit 1807a1aaf5
1 changed files with 12 additions and 2 deletions
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14
mm/slab.c
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@@ -883,6 +883,7 @@ static void __slab_error(const char *function, struct kmem_cache *cachep,
*/ */
static int use_alien_caches __read_mostly = 1; static int use_alien_caches __read_mostly = 1;
static int numa_platform __read_mostly = 1;
static int __init noaliencache_setup(char *s) static int __init noaliencache_setup(char *s)
{ {
use_alien_caches = 0; use_alien_caches = 0;
@@ -1399,8 +1400,10 @@ void __init kmem_cache_init(void)
int order; int order;
int node; int node;
if (num_possible_nodes() == 1) if (num_possible_nodes() == 1) {
use_alien_caches = 0; use_alien_caches = 0;
numa_platform = 0;
}
for (i = 0; i < NUM_INIT_LISTS; i++) { for (i = 0; i < NUM_INIT_LISTS; i++) {
kmem_list3_init(&initkmem_list3[i]); kmem_list3_init(&initkmem_list3[i]);
@@ -3558,7 +3561,14 @@ static inline void __cache_free(struct kmem_cache *cachep, void *objp)
check_irq_off(); check_irq_off();
objp = cache_free_debugcheck(cachep, objp, __builtin_return_address(0)); objp = cache_free_debugcheck(cachep, objp, __builtin_return_address(0));
if (cache_free_alien(cachep, objp)) /*
* Skip calling cache_free_alien() when the platform is not numa.
* This will avoid cache misses that happen while accessing slabp (which
* is per page memory reference) to get nodeid. Instead use a global
* variable to skip the call, which is mostly likely to be present in
* the cache.
*/
if (numa_platform && cache_free_alien(cachep, objp))
return; return;
if (likely(ac->avail < ac->limit)) { if (likely(ac->avail < ac->limit)) {