From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from smtp1.linuxfoundation.org (smtp1.linux-foundation.org [172.17.192.35]) by mail.linuxfoundation.org (Postfix) with ESMTPS id 3A56B4D4 for ; Wed, 13 Aug 2014 04:04:01 +0000 (UTC) Received: from mail-pa0-f54.google.com (mail-pa0-f54.google.com [209.85.220.54]) by smtp1.linuxfoundation.org (Postfix) with ESMTPS id E0DB81F97E for ; Wed, 13 Aug 2014 04:04:00 +0000 (UTC) Received: by mail-pa0-f54.google.com with SMTP id fa1so14179727pad.13 for ; Tue, 12 Aug 2014 21:04:00 -0700 (PDT) Message-ID: <53EAE3AD.9040203@linaro.org> Date: Tue, 12 Aug 2014 21:03:57 -0700 From: John Stultz MIME-Version: 1.0 To: Ben Hutchings References: <1407895613.3017.138.camel@deadeye.wl.decadent.org.uk> In-Reply-To: <1407895613.3017.138.camel@deadeye.wl.decadent.org.uk> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Cc: "Joseph S. Myers" , ksummit-discuss@lists.linuxfoundation.org, lkml Subject: Re: [Ksummit-discuss] 2038 Kernel Summit Discussion Fodder List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On 08/12/2014 07:06 PM, Ben Hutchings wrote: > On Tue, 2014-08-12 at 17:01 -0700, John Stultz wrote: > [...] >> The downsides here are many. The distros will probably hate this idea,= > I certainly hate the idea of adding another 32-bit port to Debian. > I think that it's OK for traditional distros to say 'just upgrade to > 64bit' while you solve the problem for 32-bit embedded systems where > there's probably little demand for supporting multiple ABIs at once. So I don't necessarily disagree, but if the rule really is "we don't break userspace" we will need a solution that at least allows for multiple ABIs from the kernel side, and we can then let distros chose if they want to handle both or not. Even in the embedded world, as usage grows with things like Android, we're starting to see more strict needs for ABI/platform stability (see the ARMv8 SWP discussion from last month). Fancy android based dashboard infotainment systems probably want to both be 2038 safe and run today's unsafe applications (hoping that they get upgraded eventually). > >> as it requires rebuilding the world, and maintaining another legacy >> architecture support. I=E2=80=99m also not completely sure how robust >> multi-arch packaging is in the face of having to handle 3-4 >> architectures on one system. > dpkg multiarch covers this just fine, while I believe RPM is limited to= > biarch. > >> On the kernel side, it also adds more complexity, where we have to add= >> even more complex compat support for 64bit systems to handle all the >> various 32bit applications possible. > [...] > > Didn't we need to do this already to support x32? Have compat ioctls > involving time been botched? I'm not sure exactly what you mean here, but yea, its very much like supporting something like x32, but its one more to the list and has to be supported on both 32 and 64 architectures. thanks -john