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| author | Siddha, Suresh B <suresh.b.siddha@intel.com> | 2007-08-22 14:01:49 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@woody.linux-foundation.org> | 2007-08-22 19:52:46 -0700 |
| commit | 1807a1aaf5f2a35ea6d4b527b28bc8889d255a2f (patch) | |
| tree | 8b07b08bedebc9bc09648fa3443041a03121733f /mm | |
| parent | 32d219854d31daba3407389ada1d454a4cd86fda (diff) | |
| download | lwn-1807a1aaf5f2a35ea6d4b527b28bc8889d255a2f.tar.gz lwn-1807a1aaf5f2a35ea6d4b527b28bc8889d255a2f.zip | |
slab: skip calling cache_free_alien() when the platform is not numa capable
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>
Diffstat (limited to 'mm')
| -rw-r--r-- | mm/slab.c | 14 |
1 files changed, 12 insertions, 2 deletions
diff --git a/mm/slab.c b/mm/slab.c index a684778b2b41..6f6abef83a1a 100644 --- a/mm/slab.c +++ b/mm/slab.c @@ -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 numa_platform __read_mostly = 1; static int __init noaliencache_setup(char *s) { use_alien_caches = 0; @@ -1399,8 +1400,10 @@ void __init kmem_cache_init(void) int order; int node; - if (num_possible_nodes() == 1) + if (num_possible_nodes() == 1) { use_alien_caches = 0; + numa_platform = 0; + } for (i = 0; i < NUM_INIT_LISTS; 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(); 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; if (likely(ac->avail < ac->limit)) { |