From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754654AbXLSSNx (ORCPT ); Wed, 19 Dec 2007 13:13:53 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752850AbXLSSNm (ORCPT ); Wed, 19 Dec 2007 13:13:42 -0500 Received: from brick.kernel.dk ([87.55.233.238]:7528 "EHLO kernel.dk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752630AbXLSSNl (ORCPT ); Wed, 19 Dec 2007 13:13:41 -0500 Date: Wed, 19 Dec 2007 19:13:37 +0100 From: Jens Axboe To: Nick Piggin Cc: linux-scsi@vger.kernel.org, Linux Kernel Mailing List Subject: Re: [rfc][patch 1/3] block: non-atomic queue_flags prep Message-ID: <20071219181336.GC10470@kernel.dk> References: <20071215054315.GA30335@wotan.suse.de> <20071218074439.GB31964@kernel.dk> <20071218081350.GA32114@wotan.suse.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20071218081350.GA32114@wotan.suse.de> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Dec 18 2007, Nick Piggin wrote: > On Tue, Dec 18, 2007 at 08:44:40AM +0100, Jens Axboe wrote: > > On Sat, Dec 15 2007, Nick Piggin wrote: > > > Hi, > > > > > > This is just an idea I had, which might make request processing a little > > > bit cheaper depending on queue behaviour. For example if it is getting plugged > > > unplugged frequently (as I think is the case for some database workloads), > > > then we might save one or two atomic operations per request. > > > > > > Anyway, I'm not completely sure if I have ensured all queue_flags users are > > > safe (I think md may need a bit of help). But overall it seems quite doable. > > > > Looks ok to me, I'll throw it into the testing mix. Thanks Nick! > > OK... actually if you are expecting it to be widely tested, can you change > the BUG_ONs in queue_flag_set / queue_flag_clear into WARN_ON? > > That way it's less likely to take down people's systems... Agree, will do so. -- Jens Axboe