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authorPaul Menage <menage@google.com>2006-12-06 23:32:16 -0500
committerLinus Torvalds <torvalds@woody.osdl.org>2006-12-07 11:39:21 -0500
commit3395ee0588795b0b3bd889c260e55959cf2b61f5 (patch)
treeea2513a28464a5b2907a9cb71cbfb6be88389205 /mm
parent8f5be20bf87da7c7c59c5cc84f630a1eca5cc99c (diff)
[PATCH] mm: add noaliencache boot option to disable numa alien caches
When using numa=fake on non-NUMA hardware there is no benefit to having the alien caches, and they consume much memory. Add a kernel boot option to disable them. Christoph sayeth "This is good to have even on large NUMA. The problem is that the alien caches grow by the square of the size of the system in terms of nodes." Cc: Christoph Lameter <clameter@engr.sgi.com> Cc: Pekka Enberg <penberg@cs.helsinki.fi> Cc: Manfred Spraul <manfred@colorfullife.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'mm')
-rw-r--r--mm/slab.c38
1 files changed, 29 insertions, 9 deletions
diff --git a/mm/slab.c b/mm/slab.c
index 3318252f657f..bfd654c0ef41 100644
--- a/mm/slab.c
+++ b/mm/slab.c
@@ -869,6 +869,22 @@ static void __slab_error(const char *function, struct kmem_cache *cachep,
869 dump_stack(); 869 dump_stack();
870} 870}
871 871
872/*
873 * By default on NUMA we use alien caches to stage the freeing of
874 * objects allocated from other nodes. This causes massive memory
875 * inefficiencies when using fake NUMA setup to split memory into a
876 * large number of small nodes, so it can be disabled on the command
877 * line
878 */
879
880static int use_alien_caches __read_mostly = 1;
881static int __init noaliencache_setup(char *s)
882{
883 use_alien_caches = 0;
884 return 1;
885}
886__setup("noaliencache", noaliencache_setup);
887
872#ifdef CONFIG_NUMA 888#ifdef CONFIG_NUMA
873/* 889/*
874 * Special reaping functions for NUMA systems called from cache_reap(). 890 * Special reaping functions for NUMA systems called from cache_reap().
@@ -1117,7 +1133,7 @@ static inline int cache_free_alien(struct kmem_cache *cachep, void *objp)
1117 * Make sure we are not freeing a object from another node to the array 1133 * Make sure we are not freeing a object from another node to the array
1118 * cache on this cpu. 1134 * cache on this cpu.
1119 */ 1135 */
1120 if (likely(slabp->nodeid == node)) 1136 if (likely(slabp->nodeid == node) || unlikely(!use_alien_caches))
1121 return 0; 1137 return 0;
1122 1138
1123 l3 = cachep->nodelists[node]; 1139 l3 = cachep->nodelists[node];
@@ -1195,7 +1211,7 @@ static int __cpuinit cpuup_callback(struct notifier_block *nfb,
1195 list_for_each_entry(cachep, &cache_chain, next) { 1211 list_for_each_entry(cachep, &cache_chain, next) {
1196 struct array_cache *nc; 1212 struct array_cache *nc;
1197 struct array_cache *shared; 1213 struct array_cache *shared;
1198 struct array_cache **alien; 1214 struct array_cache **alien = NULL;
1199 1215
1200 nc = alloc_arraycache(node, cachep->limit, 1216 nc = alloc_arraycache(node, cachep->limit,
1201 cachep->batchcount); 1217 cachep->batchcount);
@@ -1207,9 +1223,11 @@ static int __cpuinit cpuup_callback(struct notifier_block *nfb,
1207 if (!shared) 1223 if (!shared)
1208 goto bad; 1224 goto bad;
1209 1225
1210 alien = alloc_alien_cache(node, cachep->limit); 1226 if (use_alien_caches) {
1211 if (!alien) 1227 alien = alloc_alien_cache(node, cachep->limit);
1212 goto bad; 1228 if (!alien)
1229 goto bad;
1230 }
1213 cachep->array[cpu] = nc; 1231 cachep->array[cpu] = nc;
1214 l3 = cachep->nodelists[node]; 1232 l3 = cachep->nodelists[node];
1215 BUG_ON(!l3); 1233 BUG_ON(!l3);
@@ -3590,13 +3608,15 @@ static int alloc_kmemlist(struct kmem_cache *cachep)
3590 int node; 3608 int node;
3591 struct kmem_list3 *l3; 3609 struct kmem_list3 *l3;
3592 struct array_cache *new_shared; 3610 struct array_cache *new_shared;
3593 struct array_cache **new_alien; 3611 struct array_cache **new_alien = NULL;
3594 3612
3595 for_each_online_node(node) { 3613 for_each_online_node(node) {
3596 3614
3597 new_alien = alloc_alien_cache(node, cachep->limit); 3615 if (use_alien_caches) {
3598 if (!new_alien) 3616 new_alien = alloc_alien_cache(node, cachep->limit);
3599 goto fail; 3617 if (!new_alien)
3618 goto fail;
3619 }
3600 3620
3601 new_shared = alloc_arraycache(node, 3621 new_shared = alloc_arraycache(node,
3602 cachep->shared*cachep->batchcount, 3622 cachep->shared*cachep->batchcount,