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 27FABC6FD20 for ; Fri, 24 Mar 2023 15:50:32 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1pfglK-00058w-CJ; Fri, 24 Mar 2023 08:43:18 -0400 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 1pfglJ-00058o-8d for qemu-devel@nongnu.org; Fri, 24 Mar 2023 08:43:17 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.129.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1pfgl8-0001Ym-Ec for qemu-devel@nongnu.org; Fri, 24 Mar 2023 08:43:16 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1679661781; 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=elY2A6/FTPWEW52fWSfS6y8wHd0G8tNE8SA45vZzAzk=; b=fXiMehoaZDv8W7DxMccFrB3lzuP0BCkY3dKSnZe602wq/9IpNxOOpdr7MQYo86yOXPLTJ2 YKwTVWDB1MYoRkqltDkp+mhrGQsD5BhX7OLKGn6RBA/Pe7jrts4OWpuEpIAmFgFp6JSaVF fsWE2eWo3QSVkP2yVIU3j/abVjPj86s= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-215-Lz6wtHDyMC-gpzYhZnFYLA-1; Fri, 24 Mar 2023 08:11:53 -0400 X-MC-Unique: Lz6wtHDyMC-gpzYhZnFYLA-1 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.rdu2.redhat.com [10.11.54.6]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 2C78C88F4CC; Fri, 24 Mar 2023 12:11:51 +0000 (UTC) Received: from blackfin.pond.sub.org (unknown [10.39.192.52]) by smtp.corp.redhat.com (Postfix) with ESMTPS id E54032166B29; Fri, 24 Mar 2023 12:11:42 +0000 (UTC) Received: by blackfin.pond.sub.org (Postfix, from userid 1000) id 0970521E6926; Fri, 24 Mar 2023 13:11:36 +0100 (CET) From: Markus Armbruster To: huangy81@chinatelecom.cn Cc: qemu-devel , Peter Xu , "Dr. David Alan Gilbert" , Juan Quintela , Thomas Huth , Paolo Bonzini , Eric Blake , Peter Maydell , Richard Henderson Subject: Re: [PATCH v4 06/10] migration: Introduce dirty-limit capability References: Date: Fri, 24 Mar 2023 13:11:36 +0100 In-Reply-To: (huangy's message of "Fri, 17 Feb 2023 00:18:35 +0800") Message-ID: <871qlepcw7.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 10.11.54.6 Received-SPF: pass client-ip=170.10.129.124; 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 migration dirty-limit capability, which can > be turned on before live migration and limit dirty > page rate durty live migration. > > Introduce migrate_dirty_limit function to help check > if dirty-limit capability enabled during live migration. > > Meanwhile, refactor vcpu_dirty_rate_stat_collect > so that period can be configured instead of hardcoded. > > dirty-limit capability is kind of like auto-converge > but using dirty limit instead of traditional cpu-throttle > to throttle guest down. To enable this feature, turn on > the dirty-limit capability before live migration using > migrate-set-capabilities, and set the parameters > "x-vcpu-dirty-limit-period", "vcpu-dirty-limit" suitably > to speed up convergence. > > Signed-off-by: Hyman Huang(=E9=BB=84=E5=8B=87) > Acked-by: Peter Xu [...] > diff --git a/qapi/migration.json b/qapi/migration.json > index d33cc2d582..b7a92be055 100644 > --- a/qapi/migration.json > +++ b/qapi/migration.json > @@ -477,6 +477,8 @@ > # will be handled faster. This is a performance feat= ure and > # should not affect the correctness of postcopy migra= tion. > # (since 7.1) > +# @dirty-limit: Use dirty-limit to throttle down guest if enabled. > +# (since 8.0) Feels too terse. What exactly is used and how? It's not the capability itself (although the text sure sounds like it). I guess it's the thing you set with command set-vcpu-dirty-limit. Is that used only when the capability is set? > # > # Features: > # @unstable: Members @x-colo and @x-ignore-shared are experimental. > @@ -492,7 +494,7 @@ > 'dirty-bitmaps', 'postcopy-blocktime', 'late-block-activate', > { 'name': 'x-ignore-shared', 'features': [ 'unstable' ] }, > 'validate-uuid', 'background-snapshot', > - 'zero-copy-send', 'postcopy-preempt'] } > + 'zero-copy-send', 'postcopy-preempt', 'dirty-limit'] } >=20=20 > ## > # @MigrationCapabilityStatus: [...]