From 7ced3719719669ad6bd279b45fa3c1a517b2e057 Mon Sep 17 00:00:00 2001 From: Christoph Lameter Date: Wed, 9 May 2012 10:09:53 -0500 Subject: slub: Acquire_slab() avoid loop Avoid the loop in acquire slab and simply fail if there is a conflict. This will cause the next page on the list to be considered. Acked-by: David Rientjes Signed-off-by: Christoph Lameter Signed-off-by: Pekka Enberg --- mm/slub.c | 28 +++++++++++++++------------- 1 file changed, 15 insertions(+), 13 deletions(-) (limited to 'mm/slub.c') diff --git a/mm/slub.c b/mm/slub.c index a3395c28f561..9892775349bf 100644 --- a/mm/slub.c +++ b/mm/slub.c @@ -1490,12 +1490,12 @@ static inline void remove_partial(struct kmem_cache_node *n, } /* - * Lock slab, remove from the partial list and put the object into the - * per cpu freelist. + * Remove slab from the partial list, freeze it and + * return the pointer to the freelist. * * Returns a list of objects or NULL if it fails. * - * Must hold list_lock. + * Must hold list_lock since we modify the partial list. */ static inline void *acquire_slab(struct kmem_cache *s, struct kmem_cache_node *n, struct page *page, @@ -1510,22 +1510,24 @@ static inline void *acquire_slab(struct kmem_cache *s, * The old freelist is the list of objects for the * per cpu allocation list. */ - do { - freelist = page->freelist; - counters = page->counters; - new.counters = counters; - if (mode) - new.inuse = page->objects; + freelist = page->freelist; + counters = page->counters; + new.counters = counters; + if (mode) + new.inuse = page->objects; - VM_BUG_ON(new.frozen); - new.frozen = 1; + VM_BUG_ON(new.frozen); + new.frozen = 1; - } while (!__cmpxchg_double_slab(s, page, + if (!__cmpxchg_double_slab(s, page, freelist, counters, NULL, new.counters, - "lock and freeze")); + "acquire_slab")) + + return NULL; remove_partial(n, page); + WARN_ON(!freelist); return freelist; } -- cgit v1.2.3-59-g8ed1b