From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from esa4.mentor.iphmx.com (esa4.mentor.iphmx.com [68.232.137.252]) by sourceware.org (Postfix) with ESMTPS id DE0E73858D38 for ; Thu, 22 Sep 2022 16:59:53 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org DE0E73858D38 Authentication-Results: sourceware.org; dmarc=none (p=none dis=none) header.from=codesourcery.com Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=mentor.com X-IronPort-AV: E=Sophos;i="5.93,337,1654588800"; d="scan'208";a="83454986" Received: from orw-gwy-02-in.mentorg.com ([192.94.38.167]) by esa4.mentor.iphmx.com with ESMTP; 22 Sep 2022 08:59:53 -0800 IronPort-SDR: wd+sQINFYdkhX/GAirgEuQw0lvRix1ZhG6rkNoeaMP2+Bmsx0GpHGE4RibJkj0tSavCYerLbJ3 6e0K1wSwCAlK2Xu3leRIPA9XPiNrCc/e6MNozA874FCt4fX1HYGp8gR+/ZRdGzCsGPOioTMZzj UFxIF746knsFHMHr/vPUXlB2vYNNVAptUp7jN4PIxYL9+natlFBhl6LrYchrXC7LmN8IqSp0hw Rj/iLzjK8IvYowsc+wcD1Mdzud3Q+1KEIymZqGcofhOp3r2rU95kfFsv3mV92GTKOkMEEXbz2V 0fc= Date: Thu, 22 Sep 2022 16:59:47 +0000 From: Joseph Myers X-X-Sender: jsm28@digraph.polyomino.org.uk To: Michael Hudson-Doyle CC: Stefan Liebler , GNU C Library Subject: Re: Question: Is there a plan when to require a higher Linux kernel version than 3.2? In-Reply-To: Message-ID: References: User-Agent: Alpine 2.22 (DEB 394 2020-01-19) MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" X-Originating-IP: [137.202.0.90] X-ClientProxiedBy: svr-ies-mbx-15.mgc.mentorg.com (139.181.222.15) To svr-ies-mbx-10.mgc.mentorg.com (139.181.222.10) X-Spam-Status: No, score=-3111.1 required=5.0 tests=BAYES_00,HEADER_FROM_DIFFERENT_DOMAINS,KAM_DMARC_STATUS,SPF_HELO_PASS,SPF_PASS,TXREP autolearn=no autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on server2.sourceware.org List-Id: On Thu, 22 Sep 2022, Michael Hudson-Doyle via Libc-alpha wrote: > On Thu, 22 Sept 2022 at 04:50, Joseph Myers wrote: > > > * The oldest kernel version supported on > > https://www.kernel.org/category/releases.html (currently 4.9) being new > > enough for the change to allow significant cleanups in glibc. > > > > I don't know how seriously you are suggesting moving the baseline to 4.9 or > on what timeframe, but we (Canonical) still have Ubuntu 14.04 (kernel 3.13) > in extended support until 2024 and 16.04 (kernel 4.4) until 2026 and we > would like these users to be able to use newer distributions in containers I think that container hosts running much newer distributions in containers must be expected to update the host kernel, or backport some new syscalls, rather than expecting new distributions to have libc working on a ten-year-old kernel. (New distributions probably do want to have libc that works on the kernel used by any prior version of that distribution from which in-place upgrades are supported, but that shouldn't require support for ten-year-old kernels.) To benefit significantly (in terms of source code cleanup) from updating the minimum kernel in glibc, I think the new minimum would need to be at least 4.4; older versions wouldn't allow removing lots of socketcall code, so I don't think an update would be worthwhile until we're ready to move to 4.4 or later as the new minimum. (Technically there's also the option of having an older minimum version on x86_64, which we did for a while before, since x86_64 doesn't use socketcall anyway so much of the benefit could be gained by updating the minimum on other architectures.) -- Joseph S. Myers joseph@codesourcery.com