From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on dcvr.yhbt.net X-Spam-Level: X-Spam-ASN: AS31976 209.132.180.0/23 X-Spam-Status: No, score=-3.9 required=3.0 tests=AWL,BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_EF,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,RCVD_IN_DNSWL_MED,SPF_HELO_PASS,SPF_PASS shortcircuit=no autolearn=ham autolearn_force=no version=3.4.2 Received: from sourceware.org (server1.sourceware.org [209.132.180.131]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dcvr.yhbt.net (Postfix) with ESMTPS id D84ED1F4B5 for ; Tue, 12 Nov 2019 14:13:45 +0000 (UTC) DomainKey-Signature: a=rsa-sha1; c=nofws; d=sourceware.org; h=list-id :list-unsubscribe:list-subscribe:list-archive:list-post :list-help:sender:date:from:to:cc:subject:in-reply-to:message-id :references:mime-version:content-type; q=dns; s=default; b=YSGyl CvKoSFz2caMzkAk4ddqwjfujHFbpi0i4f3eTayGWg3I+Y7AyPuAwpesJRZguqgLt prxf+lRfgzW6xBCdjT8mW16X9sju3COhUajzNFMjMZBddaPicT66VVPQRjyRo1CU SeukaLKAdoCDiDb6ivNfA0C/nh82RcdBxSLGds= DKIM-Signature: v=1; a=rsa-sha1; c=relaxed; d=sourceware.org; h=list-id :list-unsubscribe:list-subscribe:list-archive:list-post :list-help:sender:date:from:to:cc:subject:in-reply-to:message-id :references:mime-version:content-type; s=default; bh=G1z0JFrErea di4IHO0/Xv1mfIFo=; b=VbmD7jG2cIbtNHJt3I1lCfOQF8tLaPRgfc9yQWl5oEv wJh5iyy3F7WnsmquDGUzK4sDuDLORZ8V8JtuI3+MPAdrRG0yZnbYeTRQYY223xe8 BD/0f37l5BLPLvsnu3y4NLfh+6j6X2USJIZYH+87mP9jXGAB1sOhk6TfFbwCMSqw = Received: (qmail 53634 invoked by alias); 12 Nov 2019 14:13:43 -0000 Mailing-List: contact libc-alpha-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Unsubscribe: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: libc-alpha-owner@sourceware.org Received: (qmail 53614 invoked by uid 89); 12 Nov 2019 14:13:42 -0000 Authentication-Results: sourceware.org; auth=none X-HELO: esa2.mentor.iphmx.com IronPort-SDR: RMFNyH/5tQyV8Wp0rCoMr7ZHNQL4RyJEn4yrgvnslPXWPNulBcx4UnVKpLCOVgjhaOyL13NEHo J+AOSyLOLcuJrjhu2FWvSF+fjBNsESM7ZxnQKbzjgX170FiERlLQ7fiAb/esV/PxluIBq39dze eQeLmosztqDL89kde/7IOP8vV6qLZt/SUlaizTfIPAe4307gL5Y/NcjdGANmCV0Ckdr3to/Ln2 oyqy29guhSE/ntRZ6lrN1Llr+jTbKs1JjnOBffzxGogimG8moZ3pn18TiWyFK78EwBfhc+7aCv 5Dg= IronPort-SDR: Lmj/LT/glDO6X0NXVT3JVDT52FICgEARjhHbtplx+qeeQdZkkBvB79J5sN0i6Ze2sJZaJ6bXbi 45fHJxy7SHkj9jf9BuFs2wsaoISDOOoJBlKdGRaqkvNy3kn/wVoDK6pUZnj7mlthe3KHgcZP0b LRnKTHQNdX5zd5FyMeWhmmdc3Grwzh1HgxdZFHA2E7FNIbu6U1YFtzetfYhdRPsuXATiPa6VBe dsl8zY8oJ7iN8qPdet4KKzWn9tos5uGM2XEz9gD6OdFGaoh/fcaRBuAtPTJTFZ2i4n0oOnXhxc zTw= Date: Tue, 12 Nov 2019 14:13:34 +0000 From: Joseph Myers To: Lukasz Majewski CC: , Paul Eggert , Carlos O'Donell , Subject: Re: Question regarding minimal supported Linux kernel headers (now it is 3.2.0) In-Reply-To: <20191112133953.0c3594ed@jawa> Message-ID: References: <20191112133953.0c3594ed@jawa> User-Agent: Alpine 2.21 (DEB 202 2017-01-01) MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" On Tue, 12 Nov 2019, Lukasz Majewski wrote: > The pselect6 conversion has been postponed on purpose as microblaze > port gained support for pselect6 from Linux kernel 3.15. Between 3.2 > (minimal supported glibc Linux headers) and 3.15 this syscall is > emulated and hence the generic code is convoluted. > > For the above reason the conversion of pselect6 has been postponed until > the minimal glibc's Linux headers are bumped to the version after 3.15. > > Dear community - when the minimal glibc version may be increased? > > Are there any guidelines when the minimal version shall be increased > (like once per X glibc releases) ? Typically we increase the minimum kernel version used at runtime (which is generally the same as the minimum kernel headers version), to the oldest currently supported LTS Linux kernel version as listed at , when this allows some significant cleanup in glibc. I think the next increase that is likely to allow significant cleanup is moving to 4.4 as minimum kernel version (once 3.16 is EOL); 3.16 doesn't allow much cleanup, but 4.4 allows removing most of the socketcall support from glibc as all architectures have most of the separate socket syscalls in 4.4 (a few were only added later for 32-bit SPARC in the compat syscall table on 64-bit kernels). I was *also* hoping that, before the next increase to the minimum kernel version, we would have the changes Carlos proposed to remove the error on startup for a too-old kernel, so that new glibc running under an old kernel would only fail on actually trying to use one of the newer syscalls, which might be rare on x86_64, and might not occur in the case of container hosting systems that have backported newer syscalls to their older kernel. For pselect6, I suggest a preparatory change increasing the minimum version for microblaze only and removing the racy emulation code from glibc citing bug 9813, which could then be marked as FIXED with appropriate milestone set once the emulation code has been completely removed. (misc/pselect.c would change to an ENOSYS stub complete with stub_warning call.) -- Joseph S. Myers joseph@codesourcery.com