From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934420AbbEMP1J (ORCPT ); Wed, 13 May 2015 11:27:09 -0400 Received: from mx0b-00082601.pphosted.com ([67.231.153.30]:42699 "EHLO mx0a-00082601.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S933090AbbEMP1G (ORCPT ); Wed, 13 May 2015 11:27:06 -0400 Message-ID: <55536C46.4020304@fb.com> Date: Wed, 13 May 2015 11:22:46 -0400 From: Jens Axboe User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.6.0 MIME-Version: 1.0 To: Jeff Moyer CC: Shaohua Li , Subject: Re: [PATCH] blk: don't account discard request size References: <10cba6675b3e93f28b9c1c7a21e4b93b923e9531.1431467011.git.shli@fb.com> <55535D9C.3050706@fb.com> In-Reply-To: Content-Type: text/plain; charset="windows-1252"; format=flowed Content-Transfer-Encoding: 7bit X-Originating-IP: [192.168.52.13] X-Proofpoint-Spam-Reason: safe X-FB-Internal: Safe X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:5.14.151,1.0.33,0.0.0000 definitions=2015-05-13_05:2015-05-13,2015-05-13,1970-01-01 signatures=0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 05/13/2015 11:00 AM, Jeff Moyer wrote: > Jens Axboe writes: > >> That would be better. But I'm still not sure we want to turn off >> accounting for discards. For the mixed write/discard cases it's >> definitely confusing. The better option would be to account it as a >> discard and not a write. Preferably in a way that would not break >> existing tools, but so that they could get updated to support it. > > Are you suggesting adding a few fields to the end of diskstats or adding > a new proc file altogether? (or something else?) I didn't suggest any specific solution. Obviously it'd be nice if we could just extend diskstats, but that might break userland. Worth checking up on. -- Jens Axboe