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 0D758C001DE for ; Fri, 28 Jul 2023 08:06:03 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1qPIEX-0004U7-IR; Fri, 28 Jul 2023 03:49:57 -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 1qPIEA-0004Qa-PY for qemu-devel@nongnu.org; Fri, 28 Jul 2023 03:49:40 -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 1qPIE1-00055A-Eu for qemu-devel@nongnu.org; Fri, 28 Jul 2023 03:49:28 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1690530562; 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=bkGe1fEbcEoaFdKxAxSgQUkHfHZjliGd4qXwt1R/P8s=; b=GosLxjgzjig0eYHNLIDGYRqgMybGaed7B0fBqaVf9vimHCzE0dOpsacKw9GjfuZsQcMVXr xwaOfFs05fC5nfhxfN1Pmn0bRv7GQkp6go0VT0qNID/rCfgyr4+SrNISRVHB/czKTGLr+J h42Xf+xqL5mw3j0W23tdLdP4kj5HJZk= 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-37-8uvd82nWNQyXXs6IDghq0Q-1; Fri, 28 Jul 2023 03:49:18 -0400 X-MC-Unique: 8uvd82nWNQyXXs6IDghq0Q-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 4BE6D1008142; Fri, 28 Jul 2023 07:49:18 +0000 (UTC) Received: from blackfin.pond.sub.org (unknown [10.39.193.50]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 0EA7D2166B25; Fri, 28 Jul 2023 07:49:17 +0000 (UTC) Received: by blackfin.pond.sub.org (Postfix, from userid 1000) id EE37721E6690; Fri, 28 Jul 2023 09:49:16 +0200 (CEST) From: Markus Armbruster To: ~hyman Cc: qemu-devel@nongnu.org, ~hyman , Juan Quintela , Eric Blake , Peter Xu , Leonardo Bras Subject: Re: [PATCH QEMU 1/2] qapi: Reformat and craft the migration doc comments References: <169040075240.21656.5651891935411754498-1@git.sr.ht> Date: Fri, 28 Jul 2023 09:49:16 +0200 In-Reply-To: <169040075240.21656.5651891935411754498-1@git.sr.ht> (hyman@git.sr.ht's message of "Thu, 27 Jul 2023 01:27:50 +0800") Message-ID: <87y1j0lblv.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_H4=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-0.01 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 ~hyman writes: > From: Hyman Huang(=E9=BB=84=E5=8B=87) > > Reformat migration doc comments to conform to current conventions > as commit a937b6aa739 (qapi: Reformat doc comments to conform to > current conventions). > > Also, craft the dirty-limit capability comment. Split into two patches? > Signed-off-by: Hyman Huang(=E9=BB=84=E5=8B=87) > --- > qapi/migration.json | 66 +++++++++++++++++++++------------------------ > 1 file changed, 31 insertions(+), 35 deletions(-) > > diff --git a/qapi/migration.json b/qapi/migration.json > index 6b49593d2f..5d5649c885 100644 > --- a/qapi/migration.json > +++ b/qapi/migration.json > @@ -258,17 +258,17 @@ > # blocked. Present and non-empty when migration is blocked. > # (since 6.0) > # > -# @dirty-limit-throttle-time-per-round: Maximum throttle time (in micros= econds) of virtual > -# CPUs each dirty ring full round,= which shows how > -# MigrationCapability dirty-limit = affects the guest > -# during live migration. (since 8.= 1) > -# > -# @dirty-limit-ring-full-time: Estimated average dirty ring full time (i= n microseconds) > -# each dirty ring full round, note that the= value equals > -# dirty ring memory size divided by average= dirty page rate > -# of virtual CPU, which can be used to obse= rve the average > -# memory load of virtual CPU indirectly. No= te that zero > -# means guest doesn't dirty memory (since 8= .1) > +# @dirty-limit-throttle-time-per-round: Maximum throttle time > +# (in microseconds) of virtual CPUs each dirty ring full round, > +# which shows how MigrationCapability dirty-limit affects the Perhaps "for each ... round"? Remind me, what's a "dirty ring full round"? > +# guest during live migration. (Since 8.1) > +# > +# @dirty-limit-ring-full-time: Estimated average dirty ring full > +# time (in microseconds) each dirty ring full round. The value Likewise. > +# equals dirty ring memory size divided by average dirty page "the dirty ring memory size divided by the average ..." > +# rate of the virtual CPU, which can be used to observe the > +# average memory load of the virtual CPU indirectly. Note that > +# zero means guest doesn't dirty memory. (Since 8.1) Two spaces between sentences for consistency. > # > # Since: 0.14 > ## > @@ -519,15 +519,11 @@ > # are present. 'return-path' capability must be enabled to use > # it. (since 8.1) > # > -# @dirty-limit: If enabled, migration will use the dirty-limit algo to > -# throttle down guest instead of auto-converge algo. > -# Throttle algo only works when vCPU's dirtyrate greater > -# than 'vcpu-dirty-limit', read processes in guest os > -# aren't penalized any more, so this algo can improve > -# performance of vCPU during live migration. This is an > -# optional performance feature and should not affect the > -# correctness of the existing auto-converge algo. > -# (since 8.1) > +# @dirty-limit: If enabled, migration will throttle vCPUs as needed to > +# keep their dirty page rate within @vcpu-dirty-limit. This can > +# improve responsiveness of large guests during live migration, > +# and can result in more stable read performance. Requires KVM > +# with accelerator property "dirty-ring-size" set. (Since 8.1) > # > # Features: > # > @@ -822,17 +818,17 @@ > # Nodes are mapped to their 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 8.1) > +# @x-vcpu-dirty-limit-period: Periodic time (in milliseconds) of dirty > +# limit during live migration. Should be in the range 1 to 1000ms, Single space in "during live", and two space between sentences, please. > +# defaults to 1000ms. (Since 8.1) I dislike that we mix milli- and microseconds. Too late to fix, I'm afraid. Remind me, what't the "periodic time of dirty limit during live migration"? > # > # @vcpu-dirty-limit: Dirtyrate limit (MB/s) during live migration. > -# Defaults to 1. (Since 8.1) > +# Defaults to 1. (Since 8.1) > # > # Features: > # > # @unstable: Members @x-checkpoint-delay and @x-vcpu-dirty-limit-period > -# are experimental. > +# are experimental. > # > # Since: 2.4 > ## > @@ -988,17 +984,17 @@ > # Nodes are mapped to their 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 8.1) > +# @x-vcpu-dirty-limit-period: Periodic time (in milliseconds) of dirty > +# limit during live migration. Should be in the range 1 to 1000ms, Two spaces between sentences. > +# defaults to 1000ms. (Since 8.1) > # > # @vcpu-dirty-limit: Dirtyrate limit (MB/s) during live migration. > -# Defaults to 1. (Since 8.1) > +# Defaults to 1. (Since 8.1) > # > # Features: > # > # @unstable: Members @x-checkpoint-delay and @x-vcpu-dirty-limit-period > -# are experimental. > +# are experimental. > # > # TODO: either fuse back into MigrationParameters, or make > # MigrationParameters members mandatory > @@ -1191,17 +1187,17 @@ > # Nodes are mapped to their 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 8.1) > +# @x-vcpu-dirty-limit-period: Periodic time (in milliseconds) of dirty > +# limit during live migration. Should be in the range 1 to 1000ms, Two spaces between sentences. > +# defaults to 1000ms. (Since 8.1) > # > # @vcpu-dirty-limit: Dirtyrate limit (MB/s) during live migration. > -# Defaults to 1. (Since 8.1) > +# Defaults to 1. (Since 8.1) > # > # Features: > # > # @unstable: Members @x-checkpoint-delay and @x-vcpu-dirty-limit-period > -# are experimental. > +# are experimental. > # > # Since: 2.4 > ##