From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752705Ab0C1Dl4 (ORCPT ); Sat, 27 Mar 2010 23:41:56 -0400 Received: from casper.infradead.org ([85.118.1.10]:37090 "EHLO casper.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751491Ab0C1Dlz (ORCPT ); Sat, 27 Mar 2010 23:41:55 -0400 Date: Sat, 27 Mar 2010 20:42:33 -0700 From: Arjan van de Ven To: Ben Gamari Cc: linux-kernel@vger.kernel.org, tytso@mit.edu, npiggin@suse.de, mingo@elte.hu, Ruald Andreae , Jens Axboe , Olly Betts , martin f krafft Subject: Re: Poor interactive performance with I/O loads with fsync()ing Message-ID: <20100327204233.0d84542a@infradead.org> In-Reply-To: <4baeaee5.c5c2f10a.7187.2688@mx.google.com> References: <4b9fa440.12135e0a.7fc8.ffffe745@mx.google.com> <4baeaee5.c5c2f10a.7187.2688@mx.google.com> Organization: Intel X-Mailer: Claws Mail 3.7.4 (GTK+ 2.16.6; i586-redhat-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-SRS-Rewrite: SMTP reverse-path rewritten from by casper.infradead.org See http://www.infradead.org/rpr.html Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat, 27 Mar 2010 18:20:37 -0700 (PDT) Ben Gamari wrote: > Hey all, > > I have posted another profile[1] from an incident yesterday. As you > can see, both swapper and init (strange?) show up prominently in the > profile. Moreover, most processes seem to be in blk_peek_request a > disturbingly large percentage of the time. Both of these profiles > were taken with 2.6.34-rc kernels. > > Anyone have any ideas on how to proceed? Is more profile data > necessary? Are the existing profiles at all useful? Thanks, profiles tend to be about cpu usage... and are rather poor to deal with anything IO related. latencytop might get closer in giving useful information.... (btw some general suggestion.. make sure you're using noatime or relatime as mount option) -- Arjan van de Ven Intel Open Source Technology Centre For development, discussion and tips for power savings, visit http://www.lesswatts.org