From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail143.messagelabs.com (mail143.messagelabs.com [216.82.254.35]) by kanga.kvack.org (Postfix) with SMTP id 0A7D16B01CB for ; Thu, 20 May 2010 09:47:58 -0400 (EDT) Message-ID: <4BF53D8B.5090407@rsk.demon.co.uk> Date: Thu, 20 May 2010 14:47:55 +0100 From: Richard Kennedy MIME-Version: 1.0 Subject: Re: RFC: dirty_ratio back to 40% References: <4BF51B0A.1050901@redhat.com> <20100520122919.GA3420@fancy-poultry.org> In-Reply-To: <20100520122919.GA3420@fancy-poultry.org> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org To: Heinz Diehl Cc: linux-kernel@vger.kernel.org, linux-mm , lwoodman@redhat.com List-ID: On 20/05/10 13:29, Heinz Diehl wrote: > On 20.05.2010, Larry Woodman wrote: > lwoodman@redhat.com >> Increasing the dirty_ratio to 40% will regain the performance loss seen >> in several benchmarks. Whats everyone think about this??? > > These are tuneable via sysctl. What I have in my /etc/sysctl.conf is > > vm.dirty_ratio = 4 > vm.dirty_background_ratio = 2 > > This writes back the data more often and frequently, thus preventing the > system from long stalls. > > Works at least for me. AMD Quadcore, 8 GB RAM. > get_dirty_limits uses a minimum vm_dirty_ratio of 5, so you can't set it lower than that (unless you use vm_dirty_bytes). But it's interesting that you find lowering the dirty_ratio helpful. Do you have any benchmark results you can share? regards Richard -- 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