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=-2.4 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,USER_AGENT_SANE_1 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 5CA2DC5DF60 for ; Fri, 8 Nov 2019 15:48:56 +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 24D91215EA for ; Fri, 8 Nov 2019 15:48:56 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="Yx1L0sOY" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 24D91215EA 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]:56634 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1iT6VL-0004as-8L for qemu-devel@archiver.kernel.org; Fri, 08 Nov 2019 10:48:55 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:53668) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1iT6QY-0000TW-Bx for qemu-devel@nongnu.org; Fri, 08 Nov 2019 10:43:59 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1iT6QW-0001Yw-Lq for qemu-devel@nongnu.org; Fri, 08 Nov 2019 10:43:58 -0500 Received: from us-smtp-delivery-1.mimecast.com ([205.139.110.120]:25902 helo=us-smtp-1.mimecast.com) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1iT6QW-0001Yk-GV for qemu-devel@nongnu.org; Fri, 08 Nov 2019 10:43:56 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1573227836; 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=uDx5th0g9HpIcu0JF2xvZ+ctTQBM9PLpFhboxKhHl5k=; b=Yx1L0sOY3SOc0ssh+4Fw4LMxOUqmodLfuUArC+C61DwnNL3iL78j84J07vNiODj0MG/5sR tz3RXUdYbgEZ6iDVgRTvHghbuRfD0B3qmtWJ7K2p6FaunMCkZbU+MgHZb2ZjL6qJAEdAWk Sefdqy7HWkEhrNPVghn2oGWhgpsoQ3o= 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-188-j-ew9pROMzSJakllX3EOkQ-1; Fri, 08 Nov 2019 10:43:53 -0500 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 921B2800C72; Fri, 8 Nov 2019 15:43:52 +0000 (UTC) Received: from [10.3.117.38] (ovpn-117-38.phx2.redhat.com [10.3.117.38]) by smtp.corp.redhat.com (Postfix) with ESMTPS id ED7AC600C9; Fri, 8 Nov 2019 15:43:42 +0000 (UTC) Subject: Re: [PATCH] configure: Check bzip2 is available To: Laszlo Ersek , =?UTF-8?Q?Philippe_Mathieu-Daud=c3=a9?= , qemu-devel@nongnu.org References: <20191108102805.8258-1-philmd@redhat.com> <862eb773-609d-4250-b46b-d922fc5a86a7@redhat.com> From: Eric Blake Organization: Red Hat, Inc. Message-ID: <00cca0a5-7a51-f2d1-5120-821c335954b8@redhat.com> Date: Fri, 8 Nov 2019 09:43:42 -0600 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.1.1 MIME-Version: 1.0 In-Reply-To: <862eb773-609d-4250-b46b-d922fc5a86a7@redhat.com> Content-Language: en-US X-Scanned-By: MIMEDefang 2.79 on 10.5.11.11 X-MC-Unique: j-ew9pROMzSJakllX3EOkQ-1 X-Mimecast-Spam-Score: 0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: quoted-printable X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 205.139.110.120 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: qemu-trivial@nongnu.org, Thomas Huth , "Daniel P . Berrange" , Wainer dos Santos Moschetta Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On 11/8/19 5:01 AM, Laszlo Ersek wrote: >> >> Add a check in ./configure to warn the user if bzip2 is missing. >=20 > We've come full circle. Let me explain: >=20 >> >> Fixes: 536d2173b2b >=20 > So this makes me kinda grumpy. If you look at the v3 posting of the patch= that would later become commit 536d2173b2b: >=20 > http://mid.mail-archive.com/20190321113408.19929-8-lersek@redhat.com >=20 > you see the following note in the changelog: >=20 > - compress FD files with bzip2 rather than xz, so that decompression= at > "make install" time succeed on older build OSes too [Peter] >=20 > So I couldn't use xz because that was "too new" for some build OSes, but = now we also can't take bzip2 for granted because that's "too old" for some = other build OSes? This is ridiculous. >=20 > To be clear, my disagreement is only with the "Fixes" tag. For me, "Fixes= " stands for something that, in retrospect, can be proven to have been a bu= g at the time the code was *originally* committed. But, at the time, taking= "bzip2" for granted was *not* a bug. The conditions / circumstances have c= hanged more recently, and the assumption about bzip2 has been invalidated *= after* adding a dependency on bzip2. >=20 > Nonetheless, thank you for adapting the code to the potential absence of = bzip2. Can you perhaps go in some details in the commit message, near "not = included in default installations" and "freshly installed systems"? If we c= an, we should identify the exact distro release where this problem has been= encountered (and I wouldn't mind a link to the BZ or ticket under which pe= ople agreed to remove bzip2 from the default package set). bzip2 is no longer a favored compression. If we are trying to pick a=20 compression that is most likely to be present on any system, go with=20 gzip. If we are trying to pick a compression that packs tighter and=20 uncompresses faster, pick xz or zstd. But bzip2 does neither: it packs=20 slightly tighter than gzip but has slower performance in doing so, and=20 thus is no longer used as a default compression. --=20 Eric Blake, Principal Software Engineer Red Hat, Inc. +1-919-301-3226 Virtualization: qemu.org | libvirt.org