Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757742AbZCZO00 (ORCPT ); Thu, 26 Mar 2009 10:26:26 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1756831AbZCZO0S (ORCPT ); Thu, 26 Mar 2009 10:26:18 -0400 Received: from casper.infradead.org ([85.118.1.10]:41243 "EHLO casper.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756400AbZCZO0S (ORCPT ); Thu, 26 Mar 2009 10:26:18 -0400 Date: Thu, 26 Mar 2009 07:27:07 -0700 From: Arjan van de Ven To: Jens Axboe Cc: Ingo Molnar , Jan Kara , Linus Torvalds , Theodore Tso , Andrew Morton , Alan Cox , Peter Zijlstra , Nick Piggin , David Rees , Jesper Krogh , Linux Kernel Mailing List , Oleg Nesterov , Roland McGrath Subject: Re: ext3 IO latency measurements (was: Linux 2.6.29) Message-ID: <20090326072707.5a98242d@infradead.org> In-Reply-To: <20090326110815.GT27476@kernel.dk> References: <20090324041249.1133efb6.akpm@linux-foundation.org> <20090325123744.GK23439@duck.suse.cz> <20090325150041.GM32307@mit.edu> <20090325185824.GO32307@mit.edu> <20090325215137.GQ32307@mit.edu> <20090325235041.GA11024@duck.suse.cz> <20090326090630.GA9369@elte.hu> <20090326110815.GT27476@kernel.dk> Organization: Intel X-Mailer: Claws Mail 3.7.0 (GTK+ 2.14.7; i386-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 Content-Length: 805 Lines: 21 On Thu, 26 Mar 2009 12:08:15 +0100 Jens Axboe wrote: > > Did you capture the trace of the long delays in the read test case? It > can be two things, at least. One is that each little read takes much > longer than it should, the other is that we get stuck waiting on a > dirty page and hence that slows down the reads a lot. > would be interesting to run latencytop during such runs... -- Arjan van de Ven Intel Open Source Technology Centre For development, discussion and tips for power savings, visit http://www.lesswatts.org -- 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/