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=-2.4 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 AFC8BC3F2CD for ; Wed, 4 Mar 2020 03:47:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 7A34920838 for ; Wed, 4 Mar 2020 03:47:01 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="Ll+QguwZ" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387566AbgCDDrA (ORCPT ); Tue, 3 Mar 2020 22:47:00 -0500 Received: from us-smtp-2.mimecast.com ([207.211.31.81]:51494 "EHLO us-smtp-delivery-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S2387469AbgCDDrA (ORCPT ); Tue, 3 Mar 2020 22:47:00 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1583293619; 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=ldW0Bt53Z7jSSRCB6WQDAvf5XFQIl+N3b5ldTZ1uj50=; b=Ll+QguwZJG7Winuiq4CwwFlsojH2gzBPho8XtF07eMVr9uJmAFQGZfn5MSNWjXYjnmL+e8 cCKStgEIaSR5/WFVXWtAHdAwTc/Gwy009pAyr2mKLaXg8pLwEM1YZVXMcCmTZvz7qufbiI +L6uFNBr4FdlfJkOINQpjiyEY0hnKvQ= 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-369-BS6UuV6wNmSt7-y5ltrwow-1; Tue, 03 Mar 2020 22:46:55 -0500 X-MC-Unique: BS6UuV6wNmSt7-y5ltrwow-1 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 878F31088388; Wed, 4 Mar 2020 03:46:54 +0000 (UTC) Received: from ming.t460p (ovpn-8-24.pek2.redhat.com [10.72.8.24]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 25A8B5C1D4; Wed, 4 Mar 2020 03:46:48 +0000 (UTC) Date: Wed, 4 Mar 2020 11:46:44 +0800 From: Ming Lei To: Shinichiro Kawasaki Cc: "linux-block@vger.kernel.org" , Jens Axboe , Damien Le Moal Subject: Re: commit 01e99aeca397 causes longer runtime of block/004 Message-ID: <20200304034644.GA23012@ming.t460p> References: <20200304023842.gu37d4mzfbseiscw@shindev.dhcp.fujisawa.hgst.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200304023842.gu37d4mzfbseiscw@shindev.dhcp.fujisawa.hgst.com> User-Agent: Mutt/1.12.1 (2019-06-15) X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org On Wed, Mar 04, 2020 at 02:38:43AM +0000, Shinichiro Kawasaki wrote: > I noticed that blktests block/004 takes longer runtime with 5.6-rc4 than > 5.6-rc3, and found that the commit 01e99aeca397 ("blk-mq: insert passthrough > request into hctx->dispatch directly") triggers it. > > The longer runtime was observed with dm-linear device which maps SATA SMR HDD > connected via AHCI. It was not observed with dm-linear on SAS/SATA SMR HDDs > connected via SAS-HBA. Not observed with dm-linear on non-SMR HDDs either. > > Before the commit, block/004 took around 130 seconds. After the commit, it takes > around 300 seconds. I need to dig in further details to understand why the > commit makes the test case longer. > > The test case block/004 does "flush intensive workload". Is this longer runtime > expected? The following patch might address this issue: https://lore.kernel.org/linux-block/20200207190416.99928-1-sqazi@google.com/#t Please test and provide us the result. thanks, Ming