From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752668AbaJ0M6i (ORCPT ); Mon, 27 Oct 2014 08:58:38 -0400 Received: from mail-qa0-f50.google.com ([209.85.216.50]:53306 "EHLO mail-qa0-f50.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752161AbaJ0M6h (ORCPT ); Mon, 27 Oct 2014 08:58:37 -0400 Date: Mon, 27 Oct 2014 08:58:33 -0400 From: Tejun Heo To: kernel test robot Cc: LKP , Alexander Gordeev , LKML , lkp@01.org, Yuanhan Liu Subject: Re: [LKP] [AHCI] 18dcf433f3d: -3.3% fileio.requests_per_sec Message-ID: <20141027125833.GB4436@htj.dyndns.org> References: <20141027021651.GF27038@yliu-dev.sh.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20141027021651.GF27038@yliu-dev.sh.intel.com> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Oct 27, 2014 at 10:16:51AM +0800, kernel test robot wrote: > FYI, we noticed the below changes on > > commit 18dcf433f3ded61eb140a55e7048ec2fef79e723 ("AHCI: Optimize single IRQ interrupt processing") > > > 227dfb4dbf109596 18dcf433f3ded61eb140a55e70 testbox/testcase/testparams > ---------------- -------------------------- --------------------------- > %stddev %change %stddev > \ | \ > 61.60 ± 1% -3.3% 59.56 ± 0% bay/fileio/performance-600s-100%-1HDD-btrfs-64G-1024f-rndrw-sync > 61.60 -3.3% 59.56 GEO-MEAN fileio.requests_per_sec Just skimmed through it and it looks like we're getting lower IO rate w/ way higher task switch rate. Maybe this is more pronounced w/ btrfs because it also makes heavy use of worker threads. Alexander, can you please look into it? It looks like we might have to revert the commit, drop the threaded IRQ and do the split locking after that. Thanks. -- tejun