From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751299AbdAQWHg (ORCPT ); Tue, 17 Jan 2017 17:07:36 -0500 Received: from mail-pg0-f43.google.com ([74.125.83.43]:34469 "EHLO mail-pg0-f43.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751129AbdAQWHe (ORCPT ); Tue, 17 Jan 2017 17:07:34 -0500 Subject: Re: [patch] block: add blktrace C events for bio-based drivers To: Jeff Moyer , linux-block@vger.kernel.org References: Cc: agk@redhat.com, snitzer@redhat.com, dm-devel@redhat.com, shli@kernel.org, linux-kernel@vger.kernel.org, linux-raid@vger.kernel.org, hch@lst.de From: Jens Axboe Message-ID: Date: Tue, 17 Jan 2017 14:07:32 -0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.5.1 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 01/17/2017 01:57 PM, Jeff Moyer wrote: > Only a few bio-based drivers actually generate blktrace completion > (C) events. Instead of changing all bio-based drivers to call > trace_block_bio_complete, move the tracing to bio_complete, and remove > the explicit tracing from the few drivers that actually do it. After > this patch, there is exactly one caller of trace_block_bio_complete > and one caller of trace_block_rq_complete. More importantly, all > bio-based drivers now generate C events, which is useful for > performance analysis. I like the change, hate the naming. I'd prefer one of two things: - Add bio_endio_complete() instead. That name sucks too, the important part is flipping the __name() to have a trace version instead. - Mark the bio as trace completed, and keep the naming. Since it's only off the completion path, that can be just marking the bi_flags non-atomically. I probably prefer the latter. -- Jens Axboe