From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756182Ab2FVSYQ (ORCPT ); Fri, 22 Jun 2012 14:24:16 -0400 Received: from mail-pz0-f46.google.com ([209.85.210.46]:65003 "EHLO mail-pz0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752779Ab2FVSYN (ORCPT ); Fri, 22 Jun 2012 14:24:13 -0400 From: Joonsoo Kim To: Pekka Enberg Cc: Christoph Lameter , linux-kernel@vger.kernel.org, linux-mm@kvack.org, Joonsoo Kim Subject: [PATCH 2/3] slub: reduce failure of this_cpu_cmpxchg in put_cpu_partial() after unfreezing Date: Sat, 23 Jun 2012 03:22:38 +0900 Message-Id: <1340389359-2407-2-git-send-email-js1304@gmail.com> X-Mailer: git-send-email 1.7.9.5 In-Reply-To: <1340389359-2407-1-git-send-email-js1304@gmail.com> References: <1340389359-2407-1-git-send-email-js1304@gmail.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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. Signed-off-by: Joonsoo Kim diff --git a/mm/slub.c b/mm/slub.c index 92f1c0e..531d8ed 100644 --- a/mm/slub.c +++ b/mm/slub.c @@ -1968,6 +1968,7 @@ 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); -- 1.7.9.5 From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx180.postini.com [74.125.245.180]) by kanga.kvack.org (Postfix) with SMTP id CF2196B020E for ; Fri, 22 Jun 2012 14:24:13 -0400 (EDT) Received: by mail-pz0-f41.google.com with SMTP id p5so3292851dak.14 for ; Fri, 22 Jun 2012 11:24:13 -0700 (PDT) From: Joonsoo Kim Subject: [PATCH 2/3] slub: reduce failure of this_cpu_cmpxchg in put_cpu_partial() after unfreezing Date: Sat, 23 Jun 2012 03:22:38 +0900 Message-Id: <1340389359-2407-2-git-send-email-js1304@gmail.com> In-Reply-To: <1340389359-2407-1-git-send-email-js1304@gmail.com> References: <1340389359-2407-1-git-send-email-js1304@gmail.com> Sender: owner-linux-mm@kvack.org List-ID: To: Pekka Enberg Cc: Christoph Lameter , linux-kernel@vger.kernel.org, linux-mm@kvack.org, Joonsoo Kim 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. Signed-off-by: Joonsoo Kim diff --git a/mm/slub.c b/mm/slub.c index 92f1c0e..531d8ed 100644 --- a/mm/slub.c +++ b/mm/slub.c @@ -1968,6 +1968,7 @@ 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); -- 1.7.9.5 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org