From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932122Ab1BCNYJ (ORCPT ); Thu, 3 Feb 2011 08:24:09 -0500 Received: from mx1.fusionio.com ([64.244.102.30]:46774 "EHLO mx1.fusionio.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932093Ab1BCNYI (ORCPT ); Thu, 3 Feb 2011 08:24:08 -0500 X-ASG-Debug-ID: 1296739445-03d6a50f0b0caf0001-xx1T2L X-Barracuda-Envelope-From: JAxboe@fusionio.com Message-ID: <4D4AAC9A.4050407@fusionio.com> Date: Thu, 3 Feb 2011 14:24:42 +0100 From: Jens Axboe MIME-Version: 1.0 To: Mike Snitzer CC: Tejun Heo , "tytso@mit.edu" , "djwong@us.ibm.com" , "shli@kernel.org" , "neilb@suse.de" , "adilger.kernel@dilger.ca" , "jack@suse.cz" , "linux-kernel@vger.kernel.org" , "kmannth@us.ibm.com" , "cmm@us.ibm.com" , "linux-ext4@vger.kernel.org" , "rwheeler@redhat.com" , "hch@lst.de" , "josef@redhat.com" , "jmoyer@redhat.com" , "vgoyal@redhat.com" Subject: Re: [PATCH v3 1/2] block: skip elevator data initialization for flush requests References: <20110201185225.GT14211@htj.dyndns.org> <1296600373-6906-1-git-send-email-snitzer@redhat.com> <20110202225549.GA28109@redhat.com> X-ASG-Orig-Subj: Re: [PATCH v3 1/2] block: skip elevator data initialization for flush requests In-Reply-To: <20110202225549.GA28109@redhat.com> Content-Type: text/plain; charset="ISO-8859-1" Content-Transfer-Encoding: 7bit X-Barracuda-Connect: mail1.int.fusionio.com[10.101.1.21] X-Barracuda-Start-Time: 1296739445 X-Barracuda-URL: http://10.101.1.180:8000/cgi-mod/mark.cgi X-Barracuda-Spam-Score: 0.00 X-Barracuda-Spam-Status: No, SCORE=0.00 using per-user scores of TAG_LEVEL=1000.0 QUARANTINE_LEVEL=1000.0 KILL_LEVEL=9.0 tests= X-Barracuda-Spam-Report: Code version 3.2, rules version 3.2.2.54260 Rule breakdown below pts rule name description ---- ---------------------- -------------------------------------------------- Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2011-02-02 23:55, Mike Snitzer wrote: > Set REQ_SORTED, in the @rw_flags passed to the request allocator, for > any request that may be put on IO scheduler. Skip elevator data > initialization during request allocation if REQ_SORTED is not set. > > REQ_SORTED is not set for flush requests because they are never put on > the IO scheduler. That looks very wrong. REQ_SORTED gets set _when_ the request is sorted into the IO scheduler. This is gross misuse, a bad hack. -- Jens Axboe