From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.io!.POSTED.blaine.gmane.org!not-for-mail From: Po Lu via "Bug reports for GNU Emacs, the Swiss army knife of text editors" Newsgroups: gmane.emacs.bugs Subject: bug#54698: non-recursive GC marking [PATCH] Date: Fri, 08 Apr 2022 20:16:27 +0800 Message-ID: <87zgkvsrc4.fsf@yahoo.com> References: <5A577100-75CE-4C9E-A7DA-02B917662AF5@acm.org> <8735itglid.fsf@gnus.org> <8527E407-8190-4574-B8D5-BE68220AE663@acm.org> <871qyc5o0y.fsf@yahoo.com> <5BBEDBDA-4C85-4237-9EF7-5635A4950365@acm.org> <83fsmreox8.fsf@gnu.org> <83a6czekro.fsf@gnu.org> <83r16acwar.fsf@gnu.org> <87tub6zabp.fsf@yahoo.com> <87pmlsw2e9.fsf@yahoo.com> <83bkxcaylu.fsf@gnu.org> <87lewguing.fsf@yahoo.com> <87h773aixt.fsf@gnus.org> <87bkxbu6q3.fsf@yahoo.com> <87czhraicv.fsf@gnus.org> Reply-To: Po Lu Mime-Version: 1.0 Content-Type: text/plain Injection-Info: ciao.gmane.io; posting-host="blaine.gmane.org:116.202.254.214"; logging-data="26176"; mail-complaints-to="usenet@ciao.gmane.io" User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/28.0.91 (gnu/linux) Cc: p.stephani2@gmail.com, mattiase@acm.org, Eli Zaretskii , 54698@debbugs.gnu.org, rms@gnu.org To: Lars Ingebrigtsen Original-X-From: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane-mx.org@gnu.org Fri Apr 08 14:17:39 2022 Return-path: Envelope-to: geb-bug-gnu-emacs@m.gmane-mx.org Original-Received: from lists.gnu.org ([209.51.188.17]) by ciao.gmane.io with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1ncnYZ-0006Xg-2O for geb-bug-gnu-emacs@m.gmane-mx.org; 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Fri, 8 Apr 2022 12:16:37 +0000 Original-Received: by hermes--canary-production-sg3-65d7bd97b5-r89m2 (VZM Hermes SMTP Server) with ESMTPA ID 3b01ba6b95c9c5e9d991ddf3db67e692; Fri, 08 Apr 2022 12:16:33 +0000 (UTC) In-Reply-To: <87czhraicv.fsf@gnus.org> (Lars Ingebrigtsen's message of "Fri, 08 Apr 2022 14:07:44 +0200") X-Mailer: WebService/1.1.20048 mail.backend.jedi.jws.acl:role.jedi.acl.token.atz.jws.hermes.yahoo X-BeenThere: debbugs-submit@debbugs.gnu.org X-Mailman-Version: 2.1.18 Precedence: list X-BeenThere: bug-gnu-emacs@gnu.org List-Id: "Bug reports for GNU Emacs, the Swiss army knife of text editors" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane-mx.org@gnu.org Original-Sender: "bug-gnu-emacs" Xref: news.gmane.io gmane.emacs.bugs:229565 Archived-At: Lars Ingebrigtsen writes: > Users will see mysterious segfaults that they didn't see before > throughout the system. Using the default settings (which, after all, > almost everybody does), you can ask the system for virtually infinite > amounts of memory, and the system will say "OK", and if you only use a > tiny bit of that, everything will be fine. With the default settings (0), you cannot ask the system for an infinite amount of memory. The kernel will reject deliberate overcommits of memory, but will let programs like Emacs slowly run out of memory until they are killed. There is some guessing involved, and that guessing can become unpredictable, leading to behavior like what Richard saw. > With your recommended settings, programs like that will segfault > instead. Those programs which ask for huge amounts of heap and do not check the return value of malloc will crash anyway under the default kernel setting, which is why they don't exist. > It's the height of hubris as Emacs developers to recommend OS-wide > settings on something like this, and it makes us look like amateurs. Overcommit is very controversial among even the Linux developers, because it works well for some programs and does not for others. IMO, it is reasonable to recommend the option that works best for us, which is to turn overcommit off. Thanks.