From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752174Ab2AJFHH (ORCPT ); Tue, 10 Jan 2012 00:07:07 -0500 Received: from LGEMRELSE6Q.lge.com ([156.147.1.121]:62671 "EHLO LGEMRELSE6Q.lge.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751768Ab2AJFHD (ORCPT ); Tue, 10 Jan 2012 00:07:03 -0500 X-AuditID: 9c930179-b7ba8ae00000598d-04-4f0bc770438a Message-ID: <4F0BC770.1090702@lge.com> Date: Tue, 10 Jan 2012 14:06:56 +0900 From: Namhyung Kim User-Agent: Mozilla/5.0 (Windows NT 6.1; rv:8.0) Gecko/20111105 Thunderbird/8.0 MIME-Version: 1.0 To: Tejun Heo CC: Jens Axboe , linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, namhyung@gmail.com Subject: Re: [PATCH 1/2] block: introduce BIO_IN_FLIGHT flag References: <1324996113-1837-1-git-send-email-namhyung@gmail.com> <1324996113-1837-2-git-send-email-namhyung@gmail.com> <20120109015628.GB16360@mtj.dyndns.org> <4F0A57A7.4070508@lge.com> <20120109164148.GB21732@google.com> In-Reply-To: <20120109164148.GB21732@google.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Brightmail-Tracker: AAAAAA== Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi, 2012-01-10 1:41 AM, Tejun Heo wrote: > Hello, > > On Mon, Jan 09, 2012 at 11:57:43AM +0900, Namhyung Kim wrote: >> I understand your concerns. However, the blktrace cannot get >> bio->bi_flags info in its current form AFAIK. Doing it will require >> extending struct blk_io_trace and it'll cause a compatibility issue, >> I guess. > > Umm? Why can't blk_add_trace_bio_complete() look at the flags (or > whatever other states) to decide to fire off BLK_TA_COMPLETE or not? > What's the difference? No userland visible change is necessary at > all. Just make blktrace.c do the right thing. Am I missing > something? > > Thanks. > Oh I misunderstood what you said. I was thinking about filtering in pure userspace, but you meant in-kernel probe side. Right, we can change the probe to filter BIO_BOUNCED case out. But IMHO BIO_CLONED is different, since it usually routed to another device as a separate IO request. I'll cook a patch for the former soon. Thanks for the comment. Namhyung Kim