From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933554Ab0EUGSA (ORCPT ); Fri, 21 May 2010 02:18:00 -0400 Received: from 74-93-104-97-Washington.hfc.comcastbusiness.net ([74.93.104.97]:46467 "EHLO sunset.davemloft.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933282Ab0EUGRz (ORCPT ); Fri, 21 May 2010 02:17:55 -0400 Date: Thu, 20 May 2010 23:18:03 -0700 (PDT) Message-Id: <20100520.231803.168054302.davem@davemloft.net> To: lwoodman@redhat.com Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org Subject: Re: RFC: dirty_ratio back to 40% From: David Miller In-Reply-To: <4BF51B0A.1050901@redhat.com> References: <4BF51B0A.1050901@redhat.com> X-Mailer: Mew version 6.3 on Emacs 23.1 / Mule 6.0 (HANACHIRUSATO) Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Larry Woodman Date: Thu, 20 May 2010 07:20:42 -0400 > Increasing the dirty_ratio to 40% will regain the performance loss > seen in several benchmarks. Whats everyone think about this??? I've been making this change via sysctl on every single system I have, and have been doing so for quite some time. When doing a lot of GIT operations to a non-SSD disk the kernel simply can't submit the writes early enough to prevent everything getting backlogged, and then processes pile up being forced to sleep on I/O for several seconds at a time. I therefore totally support making this the default, but I know some people will be against it :-) Acked-by: David S. Miller