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=-16.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=ham 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 A4C8FC433B4 for ; Fri, 30 Apr 2021 03:13:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 709A66143D for ; Fri, 30 Apr 2021 03:13:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229615AbhD3DNs (ORCPT ); Thu, 29 Apr 2021 23:13:48 -0400 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:44790 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229577AbhD3DNs (ORCPT ); Thu, 29 Apr 2021 23:13:48 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1619752380; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=xkCOAQn3mAeIKP/aVUs7yTeyXp9Pf/9akrFUxGqjLBw=; b=WBnsd3CzoNaBsrOiNbLSftPUTtmnAFg5UT8AXdGYHVb3IFOAd+Ri8ND+++Q0JAuwfQEIDp BU5YmY9z+usDPAngcMUKGEy7DGzQqEDDBS4JC6rsK5+sEpmLHOlGTK6pDRg/to0VM4Lzsl vmXcEs7ndYSOGv/lvNYfhAZHemmcDpk= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-303-cTvOTTfZNbG6TRI9iiJFtw-1; Thu, 29 Apr 2021 23:12:58 -0400 X-MC-Unique: cTvOTTfZNbG6TRI9iiJFtw-1 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 1EC99107ACC7; Fri, 30 Apr 2021 03:12:57 +0000 (UTC) Received: from T590 (ovpn-12-77.pek2.redhat.com [10.72.12.77]) by smtp.corp.redhat.com (Postfix) with ESMTPS id E5A984EE1C; Fri, 30 Apr 2021 03:12:47 +0000 (UTC) Date: Fri, 30 Apr 2021 11:12:58 +0800 From: Ming Lei To: Bart Van Assche Cc: Jens Axboe , linux-block@vger.kernel.org, Khazhy Kumykov , Shin'ichiro Kawasaki , Hannes Reinecke , John Garry , David Jeffery Subject: Re: [PATCH V4 1/4] block: avoid double io accounting for flush request Message-ID: References: <20210429023458.3044317-1-ming.lei@redhat.com> <20210429023458.3044317-2-ming.lei@redhat.com> <254e529e-f07c-b87a-e117-07dbb02312af@acm.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <254e529e-f07c-b87a-e117-07dbb02312af@acm.org> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org On Thu, Apr 29, 2021 at 07:51:37PM -0700, Bart Van Assche wrote: > On 4/28/21 7:34 PM, Ming Lei wrote: > > For flush request, rq->end_io() may be called two times, one is from > > timeout handling(blk_mq_check_expired()), another is from normal > > completion(__blk_mq_end_request()). > > > > Move blk_account_io_flush() after flush_rq->ref drops to zero, so > > io accounting can be done just once for flush request. > > > > Signed-off-by: Ming Lei > > --- > > block/blk-flush.c | 3 +-- > > 1 file changed, 1 insertion(+), 2 deletions(-) > > > > diff --git a/block/blk-flush.c b/block/blk-flush.c > > index 7942ca6ed321..1002f6c58181 100644 > > --- a/block/blk-flush.c > > +++ b/block/blk-flush.c > > @@ -219,8 +219,6 @@ static void flush_end_io(struct request *flush_rq, blk_status_t error) > > unsigned long flags = 0; > > struct blk_flush_queue *fq = blk_get_flush_queue(q, flush_rq->mq_ctx); > > > > - blk_account_io_flush(flush_rq); > > - > > /* release the tag's ownership to the req cloned from */ > > spin_lock_irqsave(&fq->mq_flush_lock, flags); > > > > @@ -230,6 +228,7 @@ static void flush_end_io(struct request *flush_rq, blk_status_t error) > > return; > > } > > > > + blk_account_io_flush(flush_rq); > > /* > > * Flush request has to be marked as IDLE when it is really ended > > * because its .end_io() is called from timeout code path too for > > How about adding the following: > > Fixes: b68663186577 ("block: add iostat counters for flush requests") Yeah, good point, thanks! Jens, I guess you may cover that, or please let me know if V5 is needed. Thanks, Ming