From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:43733) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1d8WvC-0004Hu-Hl for qemu-devel@nongnu.org; Wed, 10 May 2017 15:05:15 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1d8Wv8-0003fy-JB for qemu-devel@nongnu.org; Wed, 10 May 2017 15:05:14 -0400 Received: from mx1.redhat.com ([209.132.183.28]:48534) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1d8Wv8-0003fO-EI for qemu-devel@nongnu.org; Wed, 10 May 2017 15:05:10 -0400 Date: Wed, 10 May 2017 20:04:59 +0100 From: "Dr. David Alan Gilbert" Message-ID: <20170510190459.GD3941@work-vm> References: <1494398933-8366-1-git-send-email-thuth@redhat.com> <20170510090841.GF31558@redhat.com> <87tw4su3iw.fsf@dusky.pond.sub.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <87tw4su3iw.fsf@dusky.pond.sub.org> Subject: Re: [Qemu-devel] [PATCH] hw/i386: Deprecate the machines pc-0.10 to pc-0.15 List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Markus Armbruster Cc: Thomas Huth , Eduardo Habkost , "Michael S. Tsirkin" , qemu-devel@nongnu.org, kraxel@redhat.com, Paolo Bonzini , Richard Henderson * Markus Armbruster (armbru@redhat.com) wrote: > Thomas Huth writes: > > > On 10.05.2017 11:08, Daniel P. Berrange wrote: > >> On Wed, May 10, 2017 at 08:48:53AM +0200, Thomas Huth wrote: > [...] > >> Also unless we're going to get more serious about automated testing to > >> validate machine type compatibility between *all* previously releases, > >> I think that 6 years / 18 releases is too long a time to have any > >> confidence in migration compatibility between versions. > > Seconded. > > > Distro vendors often offer 5 - 10 years support for certain versions of > > their Linux distros, so I think we should at least support 5 years, too. > > Non sequitur. > > Distro vendors put in serious work to keep versions working for 5 - 10 > years. We can't, and we don't. All we do is try not to break things, > which is nice, and helps the distro vendors some, but a far cry from > anything I'd dare call "support". > > Perhaps an argument could be made that us keeping to try for at least 5 > years would help distro vendors enough to be worthwhile. Maybe, but > color me skeptic. Since I'm often the one having to fix the breakages when we find they've diverged, I would prefer us to try to keep them working upstream. Every time something slips through upstream it's more work for me. Dave > >> IOW, I think you should be more aggressive in culling old machine types > >> that this patch is... > > > > Actually, I like the idea of using the major release versions for > > defining the set of removal - hoping that we will do a v3.0 next year > > which then would support the previous two major release versions 1.x and > > 2.x, but drops support for the 0.xx versions completely ... > > I wouldn't put *that* much weight into our past version numbers. If I > remember correctly, there was no more to 1.0 than a feeling of "this 0.x > thing is getting ridiculous". > -- Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK