From: Joonsoo Kim Date: Fri, 22 Jun 2012 18:22:38 +0000 (+0900) Subject: slub: reduce failure of this_cpu_cmpxchg in put_cpu_partial() after unfreezing X-Git-Url: https://rtime.felk.cvut.cz/gitweb/can-eth-gw-linux.git/commitdiff_plain/e24fc410f58cc7851188a6e996dc6ce5c4259eb4 slub: reduce failure of this_cpu_cmpxchg in put_cpu_partial() after unfreezing In current implementation, after unfreezing, we doesn't touch oldpage, so it remain 'NOT NULL'. When we call this_cpu_cmpxchg() with this old oldpage, this_cpu_cmpxchg() is mostly be failed. We can change value of oldpage to NULL after unfreezing, because unfreeze_partial() ensure that all the cpu partial slabs is removed from cpu partial list. In this time, we could expect that this_cpu_cmpxchg is mostly succeed. Acked-by: Christoph Lameter Signed-off-by: Joonsoo Kim Signed-off-by: Pekka Enberg --- diff --git a/mm/slub.c b/mm/slub.c index e131084e87a3..c67bd0a4a952 100644 --- a/mm/slub.c +++ b/mm/slub.c @@ -1962,6 +1962,7 @@ int put_cpu_partial(struct kmem_cache *s, struct page *page, int drain) local_irq_save(flags); unfreeze_partials(s); local_irq_restore(flags); + oldpage = NULL; pobjects = 0; pages = 0; stat(s, CPU_PARTIAL_DRAIN);