From mboxrd@z Thu Jan 1 00:00:00 1970 From: Marius Bakke Subject: Re: 'core-updates' spring 2018 Date: Tue, 27 Mar 2018 19:43:06 +0200 Message-ID: <87po3ph0t1.fsf@fastmail.com> References: <87h8p3jfke.fsf@fastmail.com> <87a7uuhejf.fsf@elephly.net> Mime-Version: 1.0 Content-Type: multipart/signed; boundary="=-=-="; micalg=pgp-sha512; protocol="application/pgp-signature" Return-path: Received: from eggs.gnu.org ([2001:4830:134:3::10]:39413) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1f0scu-00088R-0Q for guix-devel@gnu.org; Tue, 27 Mar 2018 13:43:17 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1f0scp-0005ek-7R for guix-devel@gnu.org; Tue, 27 Mar 2018 13:43:15 -0400 Received: from out5-smtp.messagingengine.com ([66.111.4.29]:43449) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1f0scp-0005e8-26 for guix-devel@gnu.org; Tue, 27 Mar 2018 13:43:11 -0400 In-Reply-To: <87a7uuhejf.fsf@elephly.net> List-Id: "Development of GNU Guix and the GNU System distribution." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: guix-devel-bounces+gcggd-guix-devel=m.gmane.org@gnu.org Sender: "Guix-devel" To: Ricardo Wurmus Cc: guix-devel@gnu.org --=-=-= Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Ricardo Wurmus writes: > Hi Marius, > >> 'core-updates' has seen a lot of changes recently. Some of the goodies >> include [=E2=80=A6] glibc 2.27 [=E2=80=A6] >> >> Are there other things that should go in? > > I would really like to see a patch applied to glibc that ensures that > the =E2=80=9Cprlimit64=E2=80=9D syscall is not used when running on the R= HEL 6 kernel > (2.6.32). The lack of this syscall on that kernel means that getrlimits > fails, which makes it impossible to start the JVM. > > This problem appeared with the upgrade to glibc 2.26 already, and ever > since I=E2=80=99ve been trying to minimize the damage for RHEL 6 systems = where > Guix is used as a package manager (such as the MDC). > > A work-around for glibc 2.27 that makes things work fine with the RHEL 6 > kernel would be very welcome! I=E2=80=99ve started a branch =E2=80=9Crhe= l6=E2=80=9D where the > default glibc has been bumped back to version 2.25 but I really don=E2=80= =99t > want it to be a long-lived branch; one of the reasons is that building > all packages for this old glibc version (even just on x86_64) puts our > build farms under extra stress that I would like to avoid. Are you sure prlimit64 is the only syscall that needs to be adjusted? A quick grep through through the commit log reveals some other interfaces that may need to be restored. Here is the commit that removes the fallback code for missing prlimit64: https://sourceware.org/git/?p=3Dglibc.git;a=3Dcommitdiff;h=3D695d7d138eda44= 9678a1650a8b8b58181033353f And here are similar commits I found by grepping the log for '3.2': https://sourceware.org/git/?p=3Dglibc.git;a=3Dcommitdiff;h=3De92030239abb40= 38d4f915d47021d6c037239309 https://sourceware.org/git/?p=3Dglibc.git;a=3Dcommitdiff;h=3D1721145f0341d7= 0a6d7807b172c5eb400b508fc0 https://sourceware.org/git/?p=3Dglibc.git;a=3Dcommitdiff;h=3D9a45f54310573c= 190fa270e1f80d8307750305e9 https://sourceware.org/git/?p=3Dglibc.git;a=3Dcommitdiff;h=3De8f1225ca4d4af= a4043c5267ae6dbe12268e2637 Since it's fairly late in the core-updates cycle, I think it would be better to try restoring the prlimit64 fallback on the "rhel6" branch and then revisit this during the next core-updates. This got me thinking, perhaps it's possible to run Guix through a thin hypervisor layer that uses the host virtualization facilities, or a Qemu built against glibc 2.25. This is similar to how "Docker" runs on macOS, maybe it could be used for Guix in "hostile environments" too? --=-=-= Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQEzBAEBCgAdFiEEu7At3yzq9qgNHeZDoqBt8qM6VPoFAlq6gqoACgkQoqBt8qM6 VPo51Af/Qflnl4yebcBAWV6EOJGWAbwhOkKYf4vZz+ffI2J/+wLqTAymFV7jmrzR LeVLZI1bJoFPvbxski14/lsDvbAB+wFrapiBjRGHoupGdaSy6C43if+IILzsYOwe JHhzDMvVJWUkljzOvfaGCs+P1zikabQvhTr8zriRXQMGNjQz+XAVX+YCF4PbI1s/ u8Y+gwpjwPuWvI/2s/6jt0VW0XEd3qJgZVY6hT5A/YSlpLRUQYpuE+x3jFxaVZb+ J8yFhQT7JDt9qLw6mtcjFzsPugljddZpFSlxpc0ROGO3qvEJBGa46MhLDEO7M5zy fYZDAtko3WkSAO/iRtdOv/FAAIrYuw== =OOQb -----END PGP SIGNATURE----- --=-=-=--