From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752795Ab0F1Suq (ORCPT ); Mon, 28 Jun 2010 14:50:46 -0400 Received: from 0122700014.0.fullrate.dk ([95.166.99.235]:47074 "EHLO kernel.dk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751864Ab0F1Sup (ORCPT ); Mon, 28 Jun 2010 14:50:45 -0400 Message-ID: <4C28EF04.7040309@kernel.dk> Date: Mon, 28 Jun 2010 20:50:44 +0200 From: Jens Axboe MIME-Version: 1.0 To: Jeff Moyer CC: linux-kernel@vger.kernel.org Subject: Re: [PATCH 1/2] cfq: always return false from should_idle if slice_idle is set to zero References: <1277149789-4493-1-git-send-email-jmoyer@redhat.com> <1277149789-4493-2-git-send-email-jmoyer@redhat.com> <4C1FC4CA.7030007@kernel.dk> In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 28/06/10 20.41, Jeff Moyer wrote: > Jens Axboe writes: > >> On 21/06/10 21.49, Jeff Moyer wrote: >>> Hi, >>> >>> In testing a competing fsync-ing process and a sequential reader on >>> mid-grade storage, I found that cfq was incapable of achieving the I/O >>> rates of deadline, no matter how it was tuned. Investigation, and insight >>> from Vivek (mostly the latter), led to identifying that we were still >>> idling for the last queue in the service tree. >>> >>> Modifying cfq_should_idle to not idle when slice_idle is set to zero got >>> us much closer to the performance of deadline for this workload. I have >>> one follow-on patch that gets us on-par with deadline, but I think this >>> patch stands alone. >>> >>> Comments, as always, are appreciated. >> >> This looks good. > > So.... applied to which branch? Not applied yet, unless I explicitly say it's applied, then it's not necessarily in any public git tree yet. But this will go into .35. -- Jens Axboe