Slub reloads the per cpu slab if the page does not satisfy the NUMA condition. Track those reloads since doing so has a performance impact. Signed-off-by: Christoph Lameter --- include/linux/slub_def.h | 1 + mm/slub.c | 3 +++ 2 files changed, 4 insertions(+) Index: linux-2.6/include/linux/slub_def.h =================================================================== --- linux-2.6.orig/include/linux/slub_def.h 2011-05-31 14:27:07.332880140 -0500 +++ linux-2.6/include/linux/slub_def.h 2011-05-31 14:27:17.792880073 -0500 @@ -24,6 +24,7 @@ enum stat_item { ALLOC_FROM_PARTIAL, /* Cpu slab acquired from partial list */ ALLOC_SLAB, /* Cpu slab acquired from page allocator */ ALLOC_REFILL, /* Refill cpu slab from slab freelist */ + ALLOC_NODE_MISMATCH, /* Switching cpu slab */ FREE_SLAB, /* Slab freed to the page allocator */ CPUSLAB_FLUSH, /* Abandoning of the cpu slab */ DEACTIVATE_FULL, /* Cpu slab was full when deactivated */ Index: linux-2.6/mm/slub.c =================================================================== --- linux-2.6.orig/mm/slub.c 2011-05-31 14:27:12.002880106 -0500 +++ linux-2.6/mm/slub.c 2011-05-31 14:27:17.792880073 -0500 @@ -1966,6 +1966,7 @@ static void *__slab_alloc(struct kmem_ca goto new_slab; if (unlikely(!node_match(c, node))) { + stat(s, ALLOC_NODE_MISMATCH); deactivate_slab(s, c); goto new_slab; } @@ -4675,6 +4676,7 @@ STAT_ATTR(FREE_REMOVE_PARTIAL, free_remo STAT_ATTR(ALLOC_FROM_PARTIAL, alloc_from_partial); STAT_ATTR(ALLOC_SLAB, alloc_slab); STAT_ATTR(ALLOC_REFILL, alloc_refill); +STAT_ATTR(ALLOC_NODE_MISMATCH, alloc_node_mismatch); STAT_ATTR(FREE_SLAB, free_slab); STAT_ATTR(CPUSLAB_FLUSH, cpuslab_flush); STAT_ATTR(DEACTIVATE_FULL, deactivate_full); @@ -4734,6 +4736,7 @@ static struct attribute *slab_attrs[] = &alloc_from_partial_attr.attr, &alloc_slab_attr.attr, &alloc_refill_attr.attr, + &alloc_node_mismatch_attr.attr, &free_slab_attr.attr, &cpuslab_flush_attr.attr, &deactivate_full_attr.attr,