From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754777Ab1E2UqV (ORCPT ); Sun, 29 May 2011 16:46:21 -0400 Received: from smtp-02.mandic.com.br ([200.225.81.133]:38700 "EHLO smtp-02.mandic.com.br" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753252Ab1E2UqU (ORCPT ); Sun, 29 May 2011 16:46:20 -0400 X-Greylist: delayed 396 seconds by postgrey-1.27 at vger.kernel.org; Sun, 29 May 2011 16:46:19 EDT From: Cesar Eduardo Barros To: linux-mm@kvack.org Cc: Minchan Kim , Jan Beulich , Andrew Morton , Andreas Dilger , Dan Magenheimer , Jeremy Fitzhardinge , linux-kernel@vger.kernel.org, Cesar Eduardo Barros Subject: [PATCH] cleancache: use __read_mostly for cleancache_enabled Date: Sun, 29 May 2011 17:38:18 -0300 Message-Id: <1306701498-10846-1-git-send-email-cesarb@cesarb.net> X-Mailer: git-send-email 1.7.4.4 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The global variable cleancache_enabled is read often but written to rarely. Use __read_mostly to prevent it being on the same cacheline as another variable which is written to often, which would cause cacheline bouncing. Signed-off-by: Cesar Eduardo Barros --- include/linux/cleancache.h | 2 +- mm/cleancache.c | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) diff --git a/include/linux/cleancache.h b/include/linux/cleancache.h index 04ffb2e..83fffe8 100644 --- a/include/linux/cleancache.h +++ b/include/linux/cleancache.h @@ -42,7 +42,7 @@ extern void __cleancache_put_page(struct page *); extern void __cleancache_flush_page(struct address_space *, struct page *); extern void __cleancache_flush_inode(struct address_space *); extern void __cleancache_flush_fs(struct super_block *); -extern int cleancache_enabled; +extern int cleancache_enabled __read_mostly; #ifdef CONFIG_CLEANCACHE static inline bool cleancache_fs_enabled(struct page *page) diff --git a/mm/cleancache.c b/mm/cleancache.c index bcaae4c..a3d7a22 100644 --- a/mm/cleancache.c +++ b/mm/cleancache.c @@ -24,7 +24,7 @@ * disabled), so is preferred to the slower alternative: a function * call that checks a non-global. */ -int cleancache_enabled; +int cleancache_enabled __read_mostly; EXPORT_SYMBOL(cleancache_enabled); /* -- 1.7.4.4