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=-13.5 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 B0E7BC2D0E4 for ; Fri, 27 Nov 2020 09:49:39 +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 031A0221F7 for ; Fri, 27 Nov 2020 09:49:38 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="DhbD/DpG" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 031A0221F7 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]:55724 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1kiaNl-0005t7-Kk for qemu-devel@archiver.kernel.org; Fri, 27 Nov 2020 04:49:37 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:46398) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1kiaMf-0005I0-Ri for qemu-devel@nongnu.org; Fri, 27 Nov 2020 04:48:29 -0500 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:22081) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.90_1) (envelope-from ) id 1kiaMd-0004Ij-SK for qemu-devel@nongnu.org; Fri, 27 Nov 2020 04:48:29 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1606470507; 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=Dn+wNXK127dOmnXsgMZHwhUmM+AR+iVfOUfWY/O+nkE=; b=DhbD/DpGtf7Dba+mexGQWG10m15VCoqB2lx/0f/xCpjTMRAl31WG1ZBWv3u6/Dm7Q/Ox1e ZShAUw2NZjtZj7u1vacldwaUZKjxxuVdrEy2RIZi8hGFElb5jgkxbsGK6RxXcd7Mrs2Im+ dekPicaZOQlgRymn/mBxfGxzUglUa40= 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-349-IFhDPNHbP6CXXru8F-7jng-1; Fri, 27 Nov 2020 04:48:25 -0500 X-MC-Unique: IFhDPNHbP6CXXru8F-7jng-1 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id EA02F8030B6; Fri, 27 Nov 2020 09:48:23 +0000 (UTC) Received: from blackfin.pond.sub.org (ovpn-112-103.ams2.redhat.com [10.36.112.103]) by smtp.corp.redhat.com (Postfix) with ESMTPS id B78F75D9D0; Fri, 27 Nov 2020 09:48:23 +0000 (UTC) Received: by blackfin.pond.sub.org (Postfix, from userid 1000) id 4D6E3113864E; Fri, 27 Nov 2020 10:48:22 +0100 (CET) From: Markus Armbruster To: Zeyu Jin Subject: Re: [PATCH 1/6] migration: Add multi-thread compress method References: <20201127074116.2061-1-jinzeyu@huawei.com> Date: Fri, 27 Nov 2020 10:48:22 +0100 In-Reply-To: <20201127074116.2061-1-jinzeyu@huawei.com> (Zeyu Jin's message of "Fri, 27 Nov 2020 15:41:16 +0800") Message-ID: <87zh33ruzd.fsf@dusky.pond.sub.org> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/27.1 (gnu/linux) MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=armbru@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain Received-SPF: pass client-ip=216.205.24.124; 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_H3=0.001, RCVD_IN_MSPIKE_WL=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: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Ying Fang , zhang.zhanghailiang@huawei.com, qemu-devel@nongnu.org, dgilbert@redhat.com, quintela@redhat.com Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" Kevin, Max, suggest to skip right to Qcow2CompressionType. Zeyu Jin writes: > A multi-thread compress method parameter is added to hold the method we > are going to use. By default the 'zlib' method is used to maintain the > compatibility as before. > > Signed-off-by: Zeyu Jin > Signed-off-by: Ying Fang [...] > diff --git a/qapi/migration.json b/qapi/migration.json > index 3c75820527..2ed6a55b92 100644 > --- a/qapi/migration.json > +++ b/qapi/migration.json > @@ -525,6 +525,19 @@ > 'data': [ 'none', 'zlib', > { 'name': 'zstd', 'if': 'defined(CONFIG_ZSTD)' } ] } > > +## > +# @CompressMethod: > +# > +# An enumeration of multi-thread compression methods. > +# > +# @zlib: use zlib compression method. > +# > +# Since: 6.0 > +# > +## > +{ 'enum': 'CompressMethod', > + 'data': [ 'zlib' ] } > + > ## > # @BitmapMigrationBitmapAlias: > # > @@ -599,6 +612,9 @@ > # compression, so set the decompress-threads to the number about 1/4 > # of compress-threads is adequate. > # > +# @compress-method: Set compression method to use in multi-thread compression. > +# Defaults to zlib. (Since 6.0) We already have @multifd-compression. Why do we need to control the two separately? Can you give a use case for different settings? If we do want two parameters: the names @compress-method and @multifd-compression are inconsistent. According to your comment, @compress-method applies only to multi-thread compression. That leads me to suggest renaming it to @multi-thread-compression. After PATCH 4, CompressMethod is almost the same as MultiFDCompression: { 'enum': 'CompressMethod', 'data': [ 'zlib' ] } 'data': [ 'zlib', { 'name': 'zstd', 'if': 'defined(CONFIG_ZSTD)' } ] } { 'enum': 'MultiFDCompression', 'data': [ 'none', 'zlib', { 'name': 'zstd', 'if': 'defined(CONFIG_ZSTD)' } ] } The difference is member 'none'. Why does compression 'none' make sense for multi-fd, but not for multi-thread? If the difference is wanted: the names are inconsistent. Less of an issue than member names, because type names are not externally visible. Let's make them consistent anyway. Hmm, there's also Qcow2CompressionType. That's another conversation; I'll start a new thread for it. [...]