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=-3.5 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS autolearn=no 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 EBC43C4743C for ; Mon, 21 Jun 2021 16:03:07 +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 612A761357 for ; Mon, 21 Jun 2021 16:03:07 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 612A761357 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]:42078 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1lvMOA-0008PX-6D for qemu-devel@archiver.kernel.org; Mon, 21 Jun 2021 12:03:06 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:55336) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lvML5-0005Vc-2k for qemu-devel@nongnu.org; Mon, 21 Jun 2021 11:59:55 -0400 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:40521) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lvML0-0006gy-Mc for qemu-devel@nongnu.org; Mon, 21 Jun 2021 11:59:54 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1624291188; 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=y0kHX+8joUBrEhkikRA4i06kVvjs2F2Y7x4fTgJfHpc=; b=ECT59Tudkpf/ChluDqDz56Cq4ILTi2WDnk831OZHcyhyuCeuqV+Ex8gXUs5oL6XsyVHGMP iHocGs8H6+TMvKHmq2i6WDVFmB+t8VMu56EtcEXDkFggm0imP8zoXdghjpmhiu2qQ2StLA mqMfaH7EQSzcCSaGrHiUvxKMzpEs7vE= 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-513-S72Q9QBnP9Chv9KL5aslgw-1; Mon, 21 Jun 2021 11:59:47 -0400 X-MC-Unique: S72Q9QBnP9Chv9KL5aslgw-1 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.phx2.redhat.com [10.5.11.22]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id EE65A192297D; Mon, 21 Jun 2021 15:59:45 +0000 (UTC) Received: from redhat.com (ovpn-114-105.ams2.redhat.com [10.36.114.105]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 8AF4610013D6; Mon, 21 Jun 2021 15:59:44 +0000 (UTC) Date: Mon, 21 Jun 2021 17:59:43 +0200 From: Kevin Wolf To: Paolo Bonzini Subject: Re: [PATCH RFC] meson: add option to use zstd for qcow2 compression by default Message-ID: References: <20210617195128.66675-1-vsementsov@virtuozzo.com> <8d3711a0-2716-3bc5-3710-990042e16c0b@redhat.com> MIME-Version: 1.0 In-Reply-To: <8d3711a0-2716-3bc5-3710-990042e16c0b@redhat.com> X-Scanned-By: MIMEDefang 2.84 on 10.5.11.22 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=kwolf@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Received-SPF: pass client-ip=216.205.24.124; envelope-from=kwolf@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -31 X-Spam_score: -3.2 X-Spam_bar: --- X-Spam_report: (-3.2 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.373, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_LOW=-0.7, RCVD_IN_MSPIKE_H4=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: den@openvz.org, Vladimir Sementsov-Ogievskiy , qemu-devel@nongnu.org, qemu-block@nongnu.org, mreitz@redhat.com Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" Am 21.06.2021 um 10:22 hat Paolo Bonzini geschrieben: > On 17/06/21 21:51, Vladimir Sementsov-Ogievskiy wrote: > > So, it's an RFC. I also can split the patch so that refactoring of > > qcow2_co_create() go in a separate preparation patch. > > > > Another RFC question, shouldn't we move to zstd by default in upstream > > too? > > I think backwards-incompatible changes in the past were not handled with > build options, but that can be changed. > > However I would prefer to have an option like > --with-qcow2-compression={zstd,zlib}. Meson supports multiple-choice > options, they don't have to use enabled/disabled or (if boolean) true/false. Yes, this is more extensible. > Regarding changing the default, that would make images unreadable to QEMU > 5.0 and earlier versions. Does that apply to images that have no compressed > clusters? I think it does because you could be writing compressed clusters to it later. Originally, we had only 'qemu-img convert -c' that could write compressed clusters, but today the backup job can write them, too, and it doesn't create the image file itself. Kevin