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 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 smtp.lore.kernel.org (Postfix) with ESMTPS id DA3BEC46467 for ; Wed, 11 Jan 2023 13:56:23 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1pFba8-0007sy-N7; Wed, 11 Jan 2023 08:55:56 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1pFba5-0007q1-5i for qemu-devel@nongnu.org; Wed, 11 Jan 2023 08:55:53 -0500 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1pFba2-0007Jd-Pt for qemu-devel@nongnu.org; Wed, 11 Jan 2023 08:55:52 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1673445344; 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=H+yZEMv4aGliaTVK/phgo8/47ivCfAPs6V6jkQcWRXU=; b=imJdu2g+b69E95SJBPYKw6OFk8e2U9YJvCjQEaOvJdcP67u/wpZbWMtr4A47ZbAATewuQc 9hQOsw2sl/2eeekQzXimrlOe326Banj5WxzN3tOXCoyFoIIoMtrRHXl0aDdPW1jlxZot/I 3TI2DpklWdw/JyPFOwLBFcWG1n32PjE= Received: from mimecast-mx02.redhat.com (mx3-rdu2.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-376-E6D8HWdbNVeIXUTGrDvaiQ-1; Wed, 11 Jan 2023 08:55:40 -0500 X-MC-Unique: E6D8HWdbNVeIXUTGrDvaiQ-1 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.rdu2.redhat.com [10.11.54.5]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id E222D1C0897B; Wed, 11 Jan 2023 13:55:39 +0000 (UTC) Received: from blackfin.pond.sub.org (unknown [10.39.192.78]) by smtp.corp.redhat.com (Postfix) with ESMTPS id A9A89422A9; Wed, 11 Jan 2023 13:55:39 +0000 (UTC) Received: by blackfin.pond.sub.org (Postfix, from userid 1000) id 6DC7521E675B; Wed, 11 Jan 2023 14:55:38 +0100 (CET) From: Markus Armbruster To: huangy81@chinatelecom.cn Cc: qemu-devel , Peter Xu , "Dr. David Alan Gilbert" , Paolo Bonzini , Laurent Vivier , Eric Blake , Juan Quintela , Thomas Huth , Peter Maydell , Richard Henderson Subject: Re: [PATCH RESEND v3 04/10] qapi/migration: Introduce x-vcpu-dirty-limit-period parameter References: Date: Wed, 11 Jan 2023 14:55:38 +0100 In-Reply-To: (huangy's message of "Sun, 4 Dec 2022 01:09:07 +0800") Message-ID: <87358hfa5h.fsf@pond.sub.org> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/28.2 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable X-Scanned-By: MIMEDefang 3.1 on 10.11.54.5 Received-SPF: pass client-ip=170.10.133.124; envelope-from=armbru@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.001, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H2=-0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org huangy81@chinatelecom.cn writes: > From: Hyman Huang(=E9=BB=84=E5=8B=87) > > Introduce "x-vcpu-dirty-limit-period" migration experimental > parameter, which is in the range of 1 to 1000ms and used to > make dirtyrate calculation period configurable. > > Currently with the "x-vcpu-dirty-limit-period" varies, the > total time of live migration changes, test results show the > optimal value of "x-vcpu-dirty-limit-period" ranges from > 500ms to 1000 ms. "x-vcpu-dirty-limit-period" should be made > stable once it proves best value can not be determined with > developer's experiments. I'm not a native speaker, but let me try to polish your prose anyway: The value of "x-vcpu-dirty-limit-period" affects how long live migration takes. In my testing, the optimal value of "x-vcpu-dirty-limit-period" ranges from 500ms to 1000 ms. If we can find a single value that is good enough for all use cases that matter, "x-vcpu-dirty-limit-period" can go away. Else, "x-vcpu-dirty-limit-period" should be made stable. Does this capture your intent? > Signed-off-by: Hyman Huang(=E9=BB=84=E5=8B=87) [...] > diff --git a/qapi/migration.json b/qapi/migration.json > index 88ecf86..c428bcd 100644 > --- a/qapi/migration.json > +++ b/qapi/migration.json > @@ -776,8 +776,13 @@ > # block device name if there is one, and to their= node name > # otherwise. (Since 5.2) > # > +# @x-vcpu-dirty-limit-period: Periodic time (in milliseconds) of dirty l= imit during > +# live migration. Should be in the range 1 t= o 1000ms, > +# defaults to 1000ms. (Since 7.3) 8.0, not 7.3, unless we change our versioning habits. More of the same below and later in this series; I'm not flagging it again. > +# > # Features: > -# @unstable: Member @x-checkpoint-delay is experimental. > +# @unstable: Members @x-checkpoint-delay and @x-vcpu-dirty-limit-period > +# are experimental. > # > # Since: 2.4 > ## [...]