Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752388AbdITXi7 (ORCPT ); Wed, 20 Sep 2017 19:38:59 -0400 Received: from ec2-52-27-115-49.us-west-2.compute.amazonaws.com ([52.27.115.49]:52816 "EHLO osg.samsung.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751681AbdITXiz (ORCPT ); Wed, 20 Sep 2017 19:38:55 -0400 Subject: Re: [tip:timers/core] kselftests: timers: set-timer-lat: Tweak reporting when timer fires early To: Prarit Bhargava , John Stultz , Shuah Khan Cc: lkml , Richard Cochran , "H. Peter Anvin" , Thomas Gleixner , Ingo Molnar , Stephen Boyd , Greg Hackmann , Miroslav Lichvar , linux-tip-commits@vger.kernel.org, Josef Bacik , Shuah Khan References: <04d5e9e4-ef81-a9e7-8180-2c668e3af9d0@kernel.org> <36087647-31b1-95a1-fd74-b22f7d931010@redhat.com> From: Shuah Khan Message-ID: Date: Wed, 20 Sep 2017 17:38:51 -0600 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.2.1 MIME-Version: 1.0 In-Reply-To: <36087647-31b1-95a1-fd74-b22f7d931010@redhat.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2876 Lines: 75 On 09/20/2017 06:31 AM, Prarit Bhargava wrote: > On 09/19/2017 11:36 PM, John Stultz wrote: >> On Tue, Sep 19, 2017 at 6:02 PM, Shuah Khan wrote: >>> Hi Greg, >>> >>> On 08/20/2017 03:56 AM, tip-bot for Greg Hackmann wrote: >>>> Commit-ID: a524b1184b8e86141d689fa78ad150fbf2db9b4c >>>> Gitweb: http://git.kernel.org/tip/a524b1184b8e86141d689fa78ad150fbf2db9b4c >>>> Author: Greg Hackmann >>>> AuthorDate: Tue, 25 Jul 2017 14:36:25 -0700 >>>> Committer: John Stultz >>>> CommitDate: Thu, 17 Aug 2017 12:14:54 -0700 >>>> >>>> kselftests: timers: set-timer-lat: Tweak reporting when timer fires early >>>> >>>> Rather than printing an error inside the alarm signal handler, set a >>>> flag that we check later. This keeps the test from spamming the console >>>> every time the alarm fires early. It also fixes the test exiting with >>>> error code 0 if this was the only test failure. >>>> >>>> Cc: Thomas Gleixner >>>> Cc: Ingo Molnar >>>> Cc: Miroslav Lichvar >>>> Cc: Richard Cochran >>>> Cc: Prarit Bhargava >>>> Cc: Stephen Boyd >>>> Cc: Shuah Khan >>>> Cc: linux-kselftest@vger.kernel.org >>>> Signed-off-by: Greg Hackmann >>>> Signed-off-by: John Stultz >>> >>> This commit is making the set-timer-lat hang. I reverted this commit >>> and there is no hang. Could you please take a look and see if this >>> commit should be reverted. >>> >>> make kselftest as well as make -C tools/testing/selftests/timers run_tests >>> hang. >> >> Do you have any specific details as to how the test hangs? (ie: Log >> data, as in where it might be when it hangs? Any details about the >> machine?) >> >> I'm not seeing it so far in my testing. >> > > I just ran it here and don't see any issues. I'll try on a few other boxes > to make sure. > > # make -C tools/testing/selftests/timers run_tests John/Prarit, Thanks for getting back to me. I isolated the problem to redirecting test output. If I redirect the output it hangs. ./set-timer-lat > /tmp/set-timer-lat 2>&1 it hangs. The reason I am seeing this is because there is a patch that came in recently to redirect individual test output to a separate file to make it easier to understand the test results. Looks like Commits 28be3f8f48cfb3cf024860f042d424cd4824f5f7 and/or a524b1184b8e86141d689fa78ad150fbf2db9b4c add dependency on stdin/out/err to the test. Anyway just an update. It can be reproduced easily. If we have tests that can't tolerate redirecting output, I might end up dropping the patch that is in linux-kselftest fixes fbcab13d2e2511a858590846ac2e2d7cbd830591 So fat set-timer-lat is the only one I found. thanks, -- Shuah