From 97dda4cff98bf9b97b58e3cb60e001ffa61d6053 Mon Sep 17 00:00:00 2001 From: Christoph Lameter Date: Sat, 27 Oct 2007 19:32:50 -0700 Subject: [PATCH] SLUB: Avoid checking for a valid object before zeroing on the fast path The fast path always results in a valid object. Move the check for the NULL pointer to the slow branch that calls __slab_alloc. Only __slab_alloc can return NULL if there is no memory available anymore and that case is exceedingly rare. Signed-off-by: Christoph Lameter --- mm/slub.c | 13 ++++++++----- 1 files changed, 8 insertions(+), 5 deletions(-) diff --git a/mm/slub.c b/mm/slub.c index 4d84937..6faffaf 100644 --- a/mm/slub.c +++ b/mm/slub.c @@ -1553,19 +1553,22 @@ static void __always_inline *slab_alloc(struct kmem_cache *s, local_irq_save(flags); c = get_cpu_slab(s, smp_processor_id()); - if (unlikely(!c->freelist || !node_match(c, node))) + if (unlikely(!c->freelist || !node_match(c, node))) { object = __slab_alloc(s, gfpflags, node, addr, c); - - else { + if (unlikely(!object)) { + local_irq_restore(flags); + goto out; + } + } else { object = c->freelist; c->freelist = object[c->offset]; } local_irq_restore(flags); - if (unlikely((gfpflags & __GFP_ZERO) && object)) + if (unlikely((gfpflags & __GFP_ZERO))) memset(object, 0, c->objsize); - +out: return object; } -- 1.5.3.6