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=-17.5 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,NICE_REPLY_A, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 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 02434C433E9 for ; Wed, 13 Jan 2021 16:06:11 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 4288D23434 for ; Wed, 13 Jan 2021 16:06:10 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 4288D23434 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:35154 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1kziev-0008MG-35 for qemu-devel@archiver.kernel.org; Wed, 13 Jan 2021 11:06:09 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:51316) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1kzicW-0006Is-Jx for qemu-devel@nongnu.org; Wed, 13 Jan 2021 11:03:40 -0500 Received: from us-smtp-delivery-124.mimecast.com ([63.128.21.124]:48105) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.90_1) (envelope-from ) id 1kzicT-0005R6-7Y for qemu-devel@nongnu.org; Wed, 13 Jan 2021 11:03:40 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1610553813; 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: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=ldbg08NfD46plOc5nARieCeUBvHXVWaqqJ/DKkTGMYc=; b=dZQ3QMTikNJ6n7Wzz7L6cMFsGzAJfVDbSHM7M0uLId5mBxJEgZOF1JFonqL1XY62qbW6cO iT5Tp1WOxdJvMx5Sa/IJ4S8oGNZGb3Mg96GtJWNJOlEuEaRu4ZFw4AyFsyZ2Z2opgCq3mk jMDYO4XaGvS5biTl70Wq/3xztBsYRJc= 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-280-9fZaLG42MKq8GmREydBhSw-1; Wed, 13 Jan 2021 11:03:27 -0500 X-MC-Unique: 9fZaLG42MKq8GmREydBhSw-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 79E79100C60E; Wed, 13 Jan 2021 16:03:26 +0000 (UTC) Received: from [10.3.113.36] (ovpn-113-36.phx2.redhat.com [10.3.113.36]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 06B575C8A7; Wed, 13 Jan 2021 16:03:25 +0000 (UTC) Subject: Re: [PATCH 6/7] iotests/129: Limit mirror job's buffer size To: Max Reitz , qemu-block@nongnu.org References: <20210113140616.150283-1-mreitz@redhat.com> <20210113140616.150283-7-mreitz@redhat.com> From: Eric Blake Organization: Red Hat, Inc. Message-ID: <737d244a-af6e-8d8c-60d8-0b9ddd197af7@redhat.com> Date: Wed, 13 Jan 2021 10:03:25 -0600 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.6.0 MIME-Version: 1.0 In-Reply-To: <20210113140616.150283-7-mreitz@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=eblake@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Received-SPF: pass client-ip=63.128.21.124; envelope-from=eblake@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -29 X-Spam_score: -3.0 X-Spam_bar: --- X-Spam_report: (-3.0 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.25, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, NICE_REPLY_A=-0.001, RCVD_IN_DNSWL_LOW=-0.7, RCVD_IN_MSPIKE_H4=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=unavailable autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Kevin Wolf , Vladimir Sementsov-Ogievskiy , qemu-devel@nongnu.org Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On 1/13/21 8:06 AM, Max Reitz wrote: > Issuing 'stop' on the VM drains all nodes. If the mirror job has many > large requests in flight, this may lead to significant I/O that looks a > bit like the job is being drained. > > We can limit the I/O in flight by limiting the buffer size, so mirror > will make very little progress during the 'stop' drain. > > (We do not need to do anything about commit, which has a buffer size of > 512 kB by default; or backup, which goes cluster by cluster. Once we > have asynchronous requests for backup, that will change, but then we can > fine-tune the backup job to only perform a single request on a very > small chunk, too.) > > Signed-off-by: Max Reitz > --- > tests/qemu-iotests/129 | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) Reviewed-by: Eric Blake > > diff --git a/tests/qemu-iotests/129 b/tests/qemu-iotests/129 > index e6753c90ef..c3ad584ba2 100755 > --- a/tests/qemu-iotests/129 > +++ b/tests/qemu-iotests/129 > @@ -69,7 +69,7 @@ class TestStopWithBlockJob(iotests.QMPTestCase): > def test_drive_mirror(self): > self.do_test_stop("drive-mirror", device="drive0", > target=self.target_img, format=iotests.imgfmt, > - sync="full") > + sync="full", buf_size=65536) > > def test_drive_backup(self): > self.do_test_stop("drive-backup", device="drive0", > -- Eric Blake, Principal Software Engineer Red Hat, Inc. +1-919-301-3226 Virtualization: qemu.org | libvirt.org