From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1765286AbXHDQwr (ORCPT ); Sat, 4 Aug 2007 12:52:47 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1764607AbXHDQwl (ORCPT ); Sat, 4 Aug 2007 12:52:41 -0400 Received: from smtp2.linux-foundation.org ([207.189.120.14]:49917 "EHLO smtp2.linux-foundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1764407AbXHDQwk (ORCPT ); Sat, 4 Aug 2007 12:52:40 -0400 Date: Sat, 4 Aug 2007 09:51:43 -0700 From: Andrew Morton To: Ingo Molnar Cc: Linus Torvalds , Peter Zijlstra , linux-mm@kvack.org, linux-kernel@vger.kernel.org, miklos@szeredi.hu, neilb@suse.de, dgc@sgi.com, tomoki.sekiyama.qu@hitachi.com, nikita@clusterfs.com, trond.myklebust@fys.uio.no, yingchao.zhou@gmail.com, richard@rsk.demon.co.uk Subject: Re: [PATCH 00/23] per device dirty throttling -v8 Message-Id: <20070804095143.b8cc2c78.akpm@linux-foundation.org> In-Reply-To: <20070804163733.GA31001@elte.hu> References: <20070803123712.987126000@chello.nl> <20070804063217.GA25069@elte.hu> <20070804070737.GA940@elte.hu> <20070804103347.GA1956@elte.hu> <20070804163733.GA31001@elte.hu> X-Mailer: Sylpheed 2.4.1 (GTK+ 2.8.17; x86_64-unknown-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Sat, 4 Aug 2007 18:37:33 +0200 Ingo Molnar wrote: > > * Linus Torvalds wrote: > > > > hm, it turns out that it's due to vim doing an occasional fsync not > > > only on writeout, but during normal use too. "set nofsync" in the > > > .vimrc solves this problem. > > > > Yes, that's independent. The fact is, ext3 *sucks* at fsync. I hate > > hate hate it. It's totally unusable, imnsho. > > yeah, it's really ugly. But otherwise i've got no real complaint about > ext3 - with the obligatory qualification that "noatime,nodiratime" in > /etc/fstab is a must. This speeds up things very visibly - especially > when lots of files are accessed. It's kind of weird that every Linux > desktop and server is hurt by a noticeable IO performance slowdown due > to the constant atime updates, Not just more IO: it will cause great gobs of blockdev pagecache to remain in memory, too. > while there's just two real users of it: > tmpwatch [which can be configured to use ctime so it's not a big issue] > and some backup tools. (Ok, and mail-notify too i guess.) Out of tens of > thousands of applications. So for most file workloads we give Windows a > 20%-30% performance edge, for almost nothing. (for RAM-starved kernel > builds the performance difference between atime and noatime+nodiratime > setups is more on the order of 40%) > > Ingo