From 8fc9cf420b369ad1d8c2e66fb552a985c4676073 Mon Sep 17 00:00:00 2001 From: Joonsoo Kim Date: Mon, 2 Dec 2013 17:49:43 +0900 Subject: slab: make more slab management structure off the slab Now, the size of the freelist for the slab management diminish, so that the on-slab management structure can waste large space if the object of the slab is large. Consider a 128 byte sized slab. If on-slab is used, 31 objects can be in the slab. The size of the freelist for this case would be 31 bytes so that 97 bytes, that is, more than 75% of object size, are wasted. In a 64 byte sized slab case, no space is wasted if we use on-slab. So set off-slab determining constraint to 128 bytes. Acked-by: Christoph Lameter Acked-by: David Rientjes Signed-off-by: Joonsoo Kim Signed-off-by: Pekka Enberg --- mm/slab.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/mm/slab.c b/mm/slab.c index b514bf8..54eba8a 100644 --- a/mm/slab.c +++ b/mm/slab.c @@ -2264,7 +2264,7 @@ __kmem_cache_create (struct kmem_cache *cachep, unsigned long flags) * it too early on. Always use on-slab management when * SLAB_NOLEAKTRACE to avoid recursive calls into kmemleak) */ - if ((size >= (PAGE_SIZE >> 3)) && !slab_early_init && + if ((size >= (PAGE_SIZE >> 5)) && !slab_early_init && !(flags & SLAB_NOLEAKTRACE)) /* * Size is large, assume best to place the slab management obj -- cgit v1.1