From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753932AbaE1FTW (ORCPT ); Wed, 28 May 2014 01:19:22 -0400 Received: from verein.lst.de ([213.95.11.211]:33732 "EHLO newverein.lst.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750774AbaE1FTV (ORCPT ); Wed, 28 May 2014 01:19:21 -0400 Date: Wed, 28 May 2014 07:19:19 +0200 From: Christoph Hellwig To: Jens Axboe Cc: linux-kernel@vger.kernel.org Subject: Re: blk-mq: refactor request allocation Message-ID: <20140528051919.GA21566@lst.de> References: <1401217190-32453-1-git-send-email-hch@lst.de> <5384FC60.1070103@fb.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <5384FC60.1070103@fb.com> User-Agent: Mutt/1.5.17 (2007-11-01) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, May 27, 2014 at 02:58:08PM -0600, Jens Axboe wrote: > On 05/27/2014 12:59 PM, Christoph Hellwig wrote: > > This series streamlines the request allocation path. > > > > Series looks innocuous enough to me, but it's about a 1.5% performance > drop here with an actual device. These tests are very stable, anything > over ~0.1% is definitely outside of noise. I repeated and rebooted a few > times and tested both, it's persistent. No smoking guns in the profile. Can you do a bisect to narrow it down to one of the patches?