From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 17170 invoked by alias); 7 Oct 2019 21:00:04 -0000 Mailing-List: contact libc-alpha-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: libc-alpha-owner@sourceware.org Received: (qmail 17141 invoked by uid 89); 7 Oct 2019 21:00:03 -0000 Authentication-Results: sourceware.org; auth=none X-Spam-SWARE-Status: No, score=-2.7 required=5.0 tests=AWL,BAYES_00,SPF_PASS autolearn=ham version=3.3.1 spammy=H*MI:sk:2019073, H*MI:sk:875zmg9, H*MI:sk:87ftlj6, H*MI:sk:87v9uav X-HELO: esa1.mentor.iphmx.com IronPort-SDR: Cy+s5MgsjR1hHpod2hRI/q4k9zPu3rcoFKhRoQJW/ODar7d//0QYVVo/2aTqrz83bVbEquIWI+ Oz/P7vFuwdlYNdyYVNz7BAyWDw3mUkseqeozyz9926vr+8AxlIo3j7+m9WH0EBYM2vGRWlkfWs llmurKA/A9iE4eKkFUNuRQj07Ph0IFL2oNy/AzmTjM8ZZ7Lm9h/TwMoB+VUnjvu5T+enEO9drI NJCwQfZWKx351sl81fUR/6C5vI2di+y9cdtsmp4g1diANVIxyCGTp5tFe2vukzMISvbrGN7itA AeM= IronPort-SDR: HHsiw6SRVz8hVZHkIs6dJAha9vUY5dyc1DmGXS9hmdBh+WBIktrAGASBxKHDJFoOC2Qoujuzri t13E3iyX/Kk/t6OkbaFsDCJtH16k+QVJW6DNGc650RIcFUE9iiLQQxzWubLN8G8UQgDiLaqbqf Ans70qmsIXHATSPil9BqQmI0MP2Jihq2O6ybOW3X/IoRjYci2gUc+G0zYXmqD2LC8cGDUGTCO9 387+JrAHn3xQ3LVxhFDkjRK/fGKl3s6xXMryn/AAImWNuEFzQt7VDWqnrqn/yR9qlIG+7Su//q TvE= Date: Mon, 07 Oct 2019 21:00:00 -0000 From: Joseph Myers To: Adhemerval Zanella CC: Christian Brauner , Florian Weimer , Subject: Re: [PATCH 4/5] linux: Optimize posix_spawn spurious sigaction calls In-Reply-To: <63aabf91-610f-27f9-bc22-96edbc1c9f5f@linaro.org> Message-ID: References: <20190731183136.21545-1-adhemerval.zanella@linaro.org> <20190731183136.21545-4-adhemerval.zanella@linaro.org> <875zmg9xjr.fsf@oldenburg2.str.redhat.com> <4266b563-5433-8bb9-78a2-af0ff14cab59@linaro.org> <87ftlj6k69.fsf@oldenburg2.str.redhat.com> <87v9uavnzs.fsf@oldenburg2.str.redhat.com> <95503672-bc82-c0bc-0a30-5724644b0037@linaro.org> <20191007182526.qqmgziscbyxietve@wittgenstein> <63aabf91-610f-27f9-bc22-96edbc1c9f5f@linaro.org> User-Agent: Alpine 2.21 (DEB 202 2017-01-01) MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Return-Path: joseph@codesourcery.com X-SW-Source: 2019-10/txt/msg00178.txt.bz2 On Mon, 7 Oct 2019, Adhemerval Zanella wrote: > However, glibc supports older kernels as old as v3.2 and it will take > some years and releases to make v5.3 or new the minimum support kernel. > And I think it would be nice to have this optimization even for older > kernels. I should note there are two reasons I haven't proposed an increase from 3.2 to a more recent minimum kernel version, given that 3.2 is no longer a maintained Linux kernel release series. 1. An increase to 3.16, the current oldest longterm kernel at , doesn't really allow much in the way of cleanups. The next minimum kernel version that would allow many cleanups is 4.4 (most separate socket syscalls available on all socketcall architectures, so most socketcall support can be removed) - I think that's the next update that brings enough benefits to be worthwhile. (And after that, the next such update would be to require 64-bit time syscalls on 32-bit architectures once all older kernel series stop being maintained - in 2024 based on the dates on that page.) 2. I was hoping that before we next increase the minimum kernel version we can have the changes Carlos was proposing to stop giving an error at startup for a too-old kernel, instead allowing code to run with syscalls possibly failing, in order to work better in the case of (new userspace in a container running under) older kernel version numbers with features possibly backported or no relevant new features actually required by glibc. -- Joseph S. Myers joseph@codesourcery.com