From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.io!.POSTED.ciao.gmane.io!not-for-mail From: Eli Zaretskii Newsgroups: gmane.emacs.bugs Subject: bug#41321: 27.0.91; Emacs aborts due to invalid pseudovector objects Date: Sun, 31 May 2020 18:48:28 +0300 Message-ID: <83367gksvn.fsf@gnu.org> References: <83zha8cgpi.fsf@gnu.org> <83k110wxte.fsf@gnu.org> <4bab5f55-95fe-cf34-e490-1d4319728395@cs.ucla.edu> <837dwyvi74.fsf@gnu.org> <1484f569-c260-9fb0-bfe1-67897de289d3@cs.ucla.edu> <83blm9tn4j.fsf@gnu.org> <4aeb8963-4fd1-fcd4-e6e1-be409ab54775@cs.ucla.edu> <83tuzzrk30.fsf@gnu.org> <749bc7d0-6376-ec2e-7f84-dcd3a3cea465@cs.ucla.edu> <83sgfjqn49.fsf@gnu.org> <7c66e510-a8e6-17d0-94b1-793b49f87a37@cs.ucla.edu> <83tuzxl6gu.fsf@gnu.org> <782f3b14-ff24-fa26-5bd1-fa0db013bf8c@cs.ucla.edu> <83r1v1l4ls.fsf@gnu.org> <3399f152-27aa-3854-d741-e9dfaaa00fc7@cs.ucla.edu> <83mu5pl1wk.fsf@gnu.org> <5c746672-9f07-0314-500c-dc46e0c5b764@cs.ucla.edu> <83imgdkyk8.fsf@gnu.org> Injection-Info: ciao.gmane.io; posting-host="ciao.gmane.io:159.69.161.202"; logging-data="119594"; mail-complaints-to="usenet@ciao.gmane.io" Cc: 41321@debbugs.gnu.org, monnier@iro.umontreal.ca, pipcet@gmail.com To: Paul Eggert Original-X-From: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane-mx.org@gnu.org Sun May 31 17:49:11 2020 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 1jfQD1-000V0D-2z for geb-bug-gnu-emacs@m.gmane-mx.org; Sun, 31 May 2020 17:49:11 +0200 Original-Received: from localhost ([::1]:39004 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jfQD0-0005CJ-4y for geb-bug-gnu-emacs@m.gmane-mx.org; Sun, 31 May 2020 11:49:10 -0400 Original-Received: from eggs.gnu.org ([2001:470:142:3::10]:50720) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1jfQCs-0005Bu-NJ for bug-gnu-emacs@gnu.org; Sun, 31 May 2020 11:49:02 -0400 Original-Received: from debbugs.gnu.org ([209.51.188.43]:50329) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1jfQCs-0005HQ-Dn for bug-gnu-emacs@gnu.org; Sun, 31 May 2020 11:49:02 -0400 Original-Received: from Debian-debbugs by debbugs.gnu.org with local (Exim 4.84_2) (envelope-from ) id 1jfQCs-0006fc-CU for bug-gnu-emacs@gnu.org; Sun, 31 May 2020 11:49:02 -0400 X-Loop: help-debbugs@gnu.org Resent-From: Eli Zaretskii Original-Sender: "Debbugs-submit" Resent-CC: bug-gnu-emacs@gnu.org Resent-Date: Sun, 31 May 2020 15:49:02 +0000 Resent-Message-ID: Resent-Sender: help-debbugs@gnu.org X-GNU-PR-Message: followup 41321 X-GNU-PR-Package: emacs Original-Received: via spool by 41321-submit@debbugs.gnu.org id=B41321.159094011525607 (code B ref 41321); Sun, 31 May 2020 15:49:02 +0000 Original-Received: (at 41321) by debbugs.gnu.org; 31 May 2020 15:48:35 +0000 Original-Received: from localhost ([127.0.0.1]:33642 helo=debbugs.gnu.org) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1jfQCR-0006ex-3i for submit@debbugs.gnu.org; Sun, 31 May 2020 11:48:35 -0400 Original-Received: from eggs.gnu.org ([209.51.188.92]:43248) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1jfQCP-0006ek-M6 for 41321@debbugs.gnu.org; Sun, 31 May 2020 11:48:34 -0400 Original-Received: from fencepost.gnu.org ([2001:470:142:3::e]:55996) by eggs.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jfQCK-0004u4-5o; Sun, 31 May 2020 11:48:28 -0400 Original-Received: from [176.228.60.248] (port=1060 helo=home-c4e4a596f7) by fencepost.gnu.org with esmtpsa (TLS1.2:RSA_AES_256_CBC_SHA1:256) (Exim 4.82) (envelope-from ) id 1jfQCJ-0002NP-KA; Sun, 31 May 2020 11:48:27 -0400 In-Reply-To: (message from Paul Eggert on Sat, 30 May 2020 15:18:53 -0700) 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:181293 Archived-At: > Cc: pipcet@gmail.com, 41321@debbugs.gnu.org, monnier@iro.umontreal.ca > From: Paul Eggert > Date: Sat, 30 May 2020 15:18:53 -0700 > > On 5/30/20 12:33 PM, Eli Zaretskii wrote: > > > Posix may require it, but do we actually know of any supported > > important platforms where this happens? > > > But your proposal is also less efficient, isn't it? If so, its more > > general nature comes at a price. > > Sure. Compared to simply making LISP_ALIGNMENT = 8 as a workaround > (which is not correct as noted above but which fixes the lost-marker > bug), the proposed patch is about a 1% CPU-time hit in my usual > benchmark (make compile-always) on a 32-bit platform compiled with > --with-wide-int (this is Ubuntu 18.04.4, gcc -m32, Xeon E3-1225 v2). We > can surely speed this up with some cost in complexity (that's what I was > working on on the master branch), but for emacs-27 I thought that > reliability took precedence over 1% performance improvements. > > I expect that most of the performance hit is not due to the > LISP_ALIGNMENT thing, it's due to the "you have to check pointers three > times" thing. In my master-branch draft I'm working on getting this down > to "you have to check pointers an average of 1+epsilon times" for some > suitable value of epsilon. I don't know yet what epsilon will be. But > anyway, this is only about improving that 1% performance hit. OK, then let's get this change into emacs-27, and thanks.