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 BB1B9CDB46E for ; Thu, 12 Oct 2023 10:07:48 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1qqsaY-0004QI-8V; Thu, 12 Oct 2023 06:06:42 -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 1qqsaW-0004Q3-Rv for qemu-devel@nongnu.org; Thu, 12 Oct 2023 06:06:40 -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 1qqsaU-0000EJ-73 for qemu-devel@nongnu.org; Thu, 12 Oct 2023 06:06:40 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1697105197; 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=Ni7ESr4ZFEwg2/RAGMxDk5GIZopbL5MLt4WFZtGDUls=; b=hIDtOzPZv9olJ+wUsHQvHNASNPaXU+TtmYrgdtvjIuJwp+977mctc8bpmCAKmAmgDaT7mI ojnES38CAV6thbTuBOU7KJn66GTbZs4Q7/9U2ic23V26GYvhzeBklwEf9f2ir+7mOfg/wX VL8bnn1ARZCBT0xMq1fv7K78nn3/xso= 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-679-VZ_Bsq0zN6G87Vz5KnsKQQ-1; Thu, 12 Oct 2023 06:06:23 -0400 X-MC-Unique: VZ_Bsq0zN6G87Vz5KnsKQQ-1 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.rdu2.redhat.com [10.11.54.2]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 8D33E811E7D; Thu, 12 Oct 2023 10:06:23 +0000 (UTC) Received: from blackfin.pond.sub.org (unknown [10.39.193.72]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 6BA2140C6CA2; Thu, 12 Oct 2023 10:06:23 +0000 (UTC) Received: by blackfin.pond.sub.org (Postfix, from userid 1000) id 5F70821E6A1F; Thu, 12 Oct 2023 12:06:22 +0200 (CEST) From: Markus Armbruster To: Juan Quintela Cc: qemu-devel@nongnu.org, Fam Zheng , Eric Blake , libvir-list@redhat.com, Leonardo Bras , Daniel P . =?utf-8?Q?Berrang=C3=A9?= , Stefan Hajnoczi , Paolo Bonzini , Fabiano Rosas , Peter Xu , qemu-block@nongnu.org, Thomas Huth Subject: Re: [PATCH v3 4/4] migration: Deprecate old compression method References: <20231011204711.9744-1-quintela@redhat.com> <20231011204711.9744-5-quintela@redhat.com> Date: Thu, 12 Oct 2023 12:06:22 +0200 In-Reply-To: <20231011204711.9744-5-quintela@redhat.com> (Juan Quintela's message of "Wed, 11 Oct 2023 22:47:11 +0200") Message-ID: <87jzrsyx29.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 X-Scanned-By: MIMEDefang 3.4.1 on 10.11.54.2 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 autolearn=unavailable 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 Juan Quintela writes: > Signed-off-by: Juan Quintela > Acked-by: Peter Xu > --- > docs/about/deprecated.rst | 8 +++ > qapi/migration.json | 102 ++++++++++++++++++++++++-------------- > migration/options.c | 13 +++++ > 3 files changed, 86 insertions(+), 37 deletions(-) > > diff --git a/docs/about/deprecated.rst b/docs/about/deprecated.rst > index e46f3df376..b92621996f 100644 > --- a/docs/about/deprecated.rst > +++ b/docs/about/deprecated.rst > @@ -441,3 +441,11 @@ Please see "QMP invocation for live storage migration with > ``driver-mirror`` + NBD" in docs/interop/live-block-operations.rst for > a detailed explanation. > > +old compression method (since 8.2) > +'''''''''''''''''''''''''''''''''' > + > +Compression method fails too much. Too many races. We are going to > +remove it if nobody fixes it. For starters, migration-test > +compression tests are disabled becase they fail randomly. If you need > +compression, use multifd compression methods. > + > diff --git a/qapi/migration.json b/qapi/migration.json > index bf6e1ac5b5..549306fa76 100644 > --- a/qapi/migration.json > +++ b/qapi/migration.json > @@ -243,7 +243,9 @@ > # > # @compression: migration compression statistics, only returned if > # compression feature is on and status is 'active' or 'completed' > -# (Since 3.1) > +# This feature is unreliable and not tested. It is recommended to > +# use multifd migration instead, which offers an alternative > +# reliable and tested compression implementation. (Since 3.1) > # > # @socket-address: Only used for tcp, to know what the real port is > # (Since 4.0) > @@ -271,8 +273,11 @@ > # > # Features: > # > -# @deprecated: @disk migration is deprecated. Use driver-mirror > -# with NBD instead. > +# @deprecated: @disk migration is deprecated. Use driver-mirror with > +# NBD instead. @compression is unreliable and untested. It is > +# recommended to use multifd migration, which offers an > +# alternative compression implementation that is reliable and > +# tested. Again, single deprecation note under "Features:", please. > # > # Since: 0.14 > ## > @@ -290,7 +295,7 @@ > '*blocked-reasons': ['str'], > '*postcopy-blocktime': 'uint32', > '*postcopy-vcpu-blocktime': ['uint32'], > - '*compression': 'CompressionStats', > + '*compression': { 'type': 'CompressionStats', 'features': ['deprecated'] }, > '*socket-address': ['SocketAddress'], > '*dirty-limit-throttle-time-per-round': 'uint64', > '*dirty-limit-ring-full-time': 'uint64'} } > @@ -445,7 +450,8 @@ > # compress and xbzrle are both on, compress only takes effect in > # the ram bulk stage, after that, it will be disabled and only > # xbzrle takes effect, this can help to minimize migration > -# traffic. The feature is disabled by default. (since 2.4 ) > +# traffic. The feature is disabled by default. Obsolete. Use Some places call it "deprecated", others "obsolete". Best to always use "deprecated". More of the same below. > +# multifd compression methods if needed. (since 2.4 ) > # > # @events: generate events for each migration state change (since 2.4 > # ) [...] Migration has grown way too many options. Thanks for pruning them back some.