From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-4.0 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, UNPARSEABLE_RELAY,URIBL_BLOCKED autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 40525C433E2 for ; Tue, 1 Sep 2020 18:37:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2B19B2078B for ; Tue, 1 Sep 2020 18:37:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727991AbgIAShk (ORCPT ); Tue, 1 Sep 2020 14:37:40 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55020 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726489AbgIAShk (ORCPT ); Tue, 1 Sep 2020 14:37:40 -0400 Received: from bhuna.collabora.co.uk (bhuna.collabora.co.uk [IPv6:2a00:1098:0:82:1000:25:2eeb:e3e3]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D3A4DC061244 for ; Tue, 1 Sep 2020 11:37:39 -0700 (PDT) Received: from [127.0.0.1] (localhost [127.0.0.1]) (Authenticated sender: krisman) with ESMTPSA id D463929A095 From: Gabriel Krisman Bertazi To: Ming Lei Cc: Jens Axboe , linux-block , kernel@collabora.com Subject: Re: [PATCH] block: Fix inflight statistic for MQ submission with !elevator Organization: Collabora References: <20200831153127.3561733-1-krisman@collabora.com> Date: Tue, 01 Sep 2020 14:37:34 -0400 In-Reply-To: (Ming Lei's message of "Tue, 1 Sep 2020 09:18:08 +0800") Message-ID: <87wo1dpclt.fsf@collabora.com> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/26.3 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org Ming Lei writes: > On Mon, Aug 31, 2020 at 11:37 PM Gabriel Krisman Bertazi > wrote: >> - if (rq->part == mi->part) >> + if (rq->part == mi->part && rq->state == MQ_RQ_IN_FLIGHT) >> mi->inflight[rq_data_dir(rq)]++; > > The fix looks fine. However, we have helper of > blk_mq_request_started() for this purpose. Thanks for the review. I was aware of blk_mq_request_started, but it forces a READ_ONCE which on Alpha includes a mb() for every tagged request, which doesn't seem necessary or desired here. I might be wrong though, memory barriers are hard. :) let's see what Jens says about the other points, so I don't spin this unnecessarily. -- Gabriel Krisman Bertazi