Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933162AbXFRXIZ (ORCPT ); Mon, 18 Jun 2007 19:08:25 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1764548AbXFRXIT (ORCPT ); Mon, 18 Jun 2007 19:08:19 -0400 Received: from mga05.intel.com ([192.55.52.89]:25452 "EHLO fmsmga101.fm.intel.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1763117AbXFRXIS (ORCPT ); Mon, 18 Jun 2007 19:08:18 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.16,436,1175497200"; d="scan'208";a="258390063" Subject: Change in default vm_dirty_ratio From: Tim Chen Reply-To: tim.c.chen@linux.intel.com To: akpm@linux-foundation.org Cc: linux-kernel@vger.kernel.org Content-Type: text/plain Organization: Intel Date: Mon, 18 Jun 2007 14:14:30 -0700 Message-Id: <1182201271.4883.22.camel@localhost.localdomain> Mime-Version: 1.0 X-Mailer: Evolution 2.0.2 (2.0.2-8) Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 816 Lines: 23 Andrew, The default vm_dirty_ratio changed from 40 to 10 for the 2.6.22-rc kernels in this patch: http://git.kernel.org/? p=linux/kernel/git/torvalds/linux-2.6.git;a=commitdiff;h=07db59bd6b0f279c31044cba6787344f63be87ea;hp=de46c33745f5e2ad594c72f2cf5f490861b16ce1 IOZone write drops by about 60% when test file size is 50 percent of memory. Rand-write drops by 90%. Is there a good reason for turning down the default dirty ratio? How will it help for most cases? Intuitively, it seems like a less aggressive writeback will have better performance. Thanks. Tim - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/