From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-4.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id A269DC282D8 for ; Sat, 2 Feb 2019 02:14:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 772922075B for ; Sat, 2 Feb 2019 02:14:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726707AbfBBCOc (ORCPT ); Fri, 1 Feb 2019 21:14:32 -0500 Received: from zimbra.cs.ucla.edu ([131.179.128.68]:49352 "EHLO zimbra.cs.ucla.edu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726246AbfBBCOc (ORCPT ); Fri, 1 Feb 2019 21:14:32 -0500 X-Greylist: delayed 442 seconds by postgrey-1.27 at vger.kernel.org; Fri, 01 Feb 2019 21:14:32 EST Received: from localhost (localhost [127.0.0.1]) by zimbra.cs.ucla.edu (Postfix) with ESMTP id B3C9E16118D; Fri, 1 Feb 2019 18:07:10 -0800 (PST) Received: from zimbra.cs.ucla.edu ([127.0.0.1]) by localhost (zimbra.cs.ucla.edu [127.0.0.1]) (amavisd-new, port 10032) with ESMTP id nS6CwHwFKwdo; Fri, 1 Feb 2019 18:07:09 -0800 (PST) Received: from localhost (localhost [127.0.0.1]) by zimbra.cs.ucla.edu (Postfix) with ESMTP id CBA601611B9; Fri, 1 Feb 2019 18:07:09 -0800 (PST) X-Virus-Scanned: amavisd-new at zimbra.cs.ucla.edu Received: from zimbra.cs.ucla.edu ([127.0.0.1]) by localhost (zimbra.cs.ucla.edu [127.0.0.1]) (amavisd-new, port 10026) with ESMTP id tUkKQ1vOdvnK; Fri, 1 Feb 2019 18:07:09 -0800 (PST) Received: from Penguin.CS.UCLA.EDU (Penguin.CS.UCLA.EDU [131.179.64.200]) by zimbra.cs.ucla.edu (Postfix) with ESMTPSA id AA2BA16118D; Fri, 1 Feb 2019 18:07:09 -0800 (PST) To: Thomas Gleixner Cc: Alex Branham , Alan Mackenzie , Eli Zaretskii , linux-kernel@vger.kernel.org, 34235@debbugs.gnu.org From: Paul Eggert Subject: Re: 0e334db6bb4b1fd1e2d72c1f3d8f004313cd9f94 (posix-timers: Fix, division by zero bug). Problems with glibc. 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Since the problem occurs only with a few Linux kernel versions and affects Emacs only when doing CPU profiling, it doesn't seem worth spending time to try to patch Emacs to work around the bug. So I installed the attached patch into emacs-26's etc/PROBLEMS file to warn users about the problem, and am closing the Emacs bug report. --------------3EDE60C2A864A50FA18F8A05 Content-Type: text/x-patch; name="0001-etc-PROBLEMS-Mention-profiler-report-bug-Bug-34235.patch" Content-Transfer-Encoding: 7bit Content-Disposition: attachment; filename*0="0001-etc-PROBLEMS-Mention-profiler-report-bug-Bug-34235.patc"; filename*1="h" >From 1243188bc4f722abf16518bf73924ce5f17750cf Mon Sep 17 00:00:00 2001 From: Paul Eggert Date: Fri, 1 Feb 2019 17:58:05 -0800 Subject: [PATCH] * etc/PROBLEMS: Mention profiler-report bug (Bug#34235). --- etc/PROBLEMS | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/etc/PROBLEMS b/etc/PROBLEMS index cab087631c..00583f016d 100644 --- a/etc/PROBLEMS +++ b/etc/PROBLEMS @@ -1850,6 +1850,12 @@ term/xterm.el) for more details. ** GNU/Linux +*** GNU/Linux: profiler-report outputs nothing. + +A few versions of the Linux kernel have timer bugs that break CPU +profiling; see Bug#34235. To fix the problem, upgrade to kernel +versions 4.19.19 or 4.20.6, or later. + *** GNU/Linux: Process output is corrupted. There is a bug in Linux kernel 2.6.10 PTYs that can cause emacs to -- 2.20.1 --------------3EDE60C2A864A50FA18F8A05--