From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752660AbZKDHko (ORCPT ); Wed, 4 Nov 2009 02:40:44 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751567AbZKDHko (ORCPT ); Wed, 4 Nov 2009 02:40:44 -0500 Received: from [95.166.99.235] ([95.166.99.235]:56141 "EHLO kernel.dk" rhost-flags-FAIL-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1751433AbZKDHkn (ORCPT ); Wed, 4 Nov 2009 02:40:43 -0500 Date: Wed, 4 Nov 2009 08:40:48 +0100 From: Jens Axboe To: Alex Shi Cc: "linux-kernel@vger.kernel.org" Subject: Re: kernel building regression on 32-rc5 kernel Message-ID: <20091104074048.GT8742@kernel.dk> References: <20091103183235.GD8742@kernel.dk> <1257297690.3819.256.camel@alexs-hp.sh.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1257297690.3819.256.camel@alexs-hp.sh.intel.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Nov 04 2009, Alex Shi wrote: > On Wed, 2009-11-04 at 02:32 +0800, Jens Axboe wrote: > > On Tue, Nov 03 2009, Shi, Alex wrote: > > > I found the kernel building will have about 20%~ 30% regressions on > > > our NHM machines. My kernel build do the following things 15 times: > > > > > > make mrproper; echo \"3\">/proc/sys/vm/drop_caches; make defconfig; > > > make -j${2timescpunumbers} > > > > > > > > > > > > Bisect found it is due to the commitment: > > > > > > commit a6151c3a5c8e1ff5a28450bc8d6a99a2a0add0a7 > > > > I looked over that commit and found one typo, can you check with this > > patch applied? > > > > diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c > > index 069a610..5802e32 100644 > > --- a/block/cfq-iosched.c > > +++ b/block/cfq-iosched.c > > @@ -2051,7 +2051,7 @@ cfq_should_preempt(struct cfq_data *cfqd, struct cfq_queue *new_cfqq, > > * it's a metadata request and the current queue is doing regular IO. > > */ > > if (rq_is_meta(rq) && !cfqq->meta_pending) > > - return false; > > + return true; > > > > /* > > * Allow an RT request to pre-empt an ongoing non-RT cfqq timeslice. > > Yes, the performance recovered with this patch on 32-rc6 kernel. Great! The patch just missed -rc6, as I had already queued it up and asked for a pull. It's in current -git. Thanks a lot for reporting! -- Jens Axboe