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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 42491C433F5 for ; Tue, 23 Nov 2021 11:06:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233834AbhKWLJd (ORCPT ); Tue, 23 Nov 2021 06:09:33 -0500 Received: from mout.gmx.net ([212.227.15.15]:60757 "EHLO mout.gmx.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233462AbhKWLJ3 (ORCPT ); Tue, 23 Nov 2021 06:09:29 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=gmx.net; s=badeba3b8450; t=1637665580; bh=iHMBuiS6NA57Im1nsN6hxnDvT25qjhF1O/kXlthv3+0=; h=X-UI-Sender-Class:Subject:From:To:Cc:Date:In-Reply-To:References; b=kB6KEt1tfgYibUyjL/EKUiAD4W/qZfamF2ghaauLBiDS6YyJ/5qJqJvFsD8+N+VAb 5rzYiXVnWA3rIjvhK2l/AvVjM+e+hHlaAICVgYXD5YZGY5XhlDoGe4gn2/q4KqKqxk j1aDPhGZmfh5RI99cMmLrkAzDzQ0SWvu0WijOOIQ= X-UI-Sender-Class: 01bb95c1-4bf8-414a-932a-4f6e2808ef9c Received: from homer.fritz.box ([185.221.148.50]) by mail.gmx.net (mrgmx004 [212.227.17.190]) with ESMTPSA (Nemesis) id 1MrhQ6-1mJUvH3pjQ-00njgI; Tue, 23 Nov 2021 12:06:19 +0100 Message-ID: <56b8e72693d5a0247beb95482bdfacf1a158a859.camel@gmx.de> Subject: Re: mm: LTP/memcg testcase regression induced by 8cd7c588decf..66ce520bb7c2 series From: Mike Galbraith To: Mel Gorman Cc: lkml Date: Tue, 23 Nov 2021 12:06:19 +0100 In-Reply-To: <20211123091304.GC3366@techsingularity.net> References: <99e779783d6c7fce96448a3402061b9dc1b3b602.camel@gmx.de> <20211123091304.GC3366@techsingularity.net> Content-Type: text/plain; charset="UTF-8" User-Agent: Evolution 3.42.1 MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Provags-ID: V03:K1:UW7zPsWz7laCjBdOEtep7m0xMCMksrn46s/yL7I7FzkfYJipKFC AWvXNBgP6Py5QDKRkPvy3H4ysFz4WmlVtJuvTrbdvNAbE30sulz0N799duw8uET3Ll1CzOK lXX6zKyZPJARNXsLYQGqkDHqrxh8fqga2APdh1ogPD5moDv60rQd09FZHmhaP8F+7U0yc2U ELpaKLJjAEUZbS0vALv3g== X-UI-Out-Filterresults: notjunk:1;V03:K0:erfRfKJAyy8=:Te38DExQX1W2/T2FkS594n o9aV6WDu65qX+hOOIpnr+k5qNeQV9caxIIxEkM18fTa8kxg7e6vmzCTZKhws1hN4XP16LebT6 AuQimSIqNOL7QK4nPyw71Usa7uc6lovGxBscrluU2XBOSY/YYNNzrkcAIsl64Kc+jhXYQQdGG ZR42xl5+9mUxN0MsqkzejdeHDZgKlC3c4FSOXboHGqBJzDw9hJFoxcU8zhl5s75xO/mqd74sf CpKaR29S0gpMUMYDuJbQpww75z4T2HZfRc+5HupMQJQo4+/9mUP/h41rYZV1fGK9N6+Ow2n4L FmMW4E0Rz7I7KsK7XG1vKmrRNv8vnkuFwVWWvoFPPj+0jl9C0/BJ1p7P0pbx85KtZTIbWfY4I PLJvwC7hJfSPSaIATl/SrOZiAY1QK7aMqdeeGxyYxEI+AhZMCmswQQdJMBGThEoPCyDBcYDtn iinm0CzXQFh4f8F9JQNdvA2Gbq2R5UYYe+veA2bIMnrLuA1n1NS335zkBJSLVuLvOkAbPCyTA WDy5wcbjjRR5opdJUpm4kgagJ2Uf2KAQRUnKCaKEKf/IFI+9vpRD0PICBHQfmswaeqaTmQ1KS 5igMHC9B7SLTtns4hyC5UhVbvmSpGvOsrSiAb23pcCzZ7B1aEO5fvDnvxPTkv9xgcCQB+woxF Z4a7w56e7UK5jeds1Y1wHwfzI86zQt+70rYdS/FPRNhNG94BhHDVlKaG3N4UDU+xNALzqyxfu FP7Icn8oScvja0c83lJ6JkOyOo628nUF0jGYclM4ULmVtzmaCXgBSYv3vwjB7FMcP2766XLEW z5bbTe7YIo5KbS4WVwUzCxvK72yWo6XSYFo+OEiaQjwitukt4q9+0rTrJpNwO48QmJAT8Zxvw vBK33KLybs68qYRfbNtP4S2I6S2jvn//jR1ZdlvqMFsZuhPXhapoI3INohVPpxKxdKd3Aa7Hi BpDThrcbyPmkmbkSPE/SBY0DAKt/qO+D8QwBZTb20VMgScJbNx5SmO8xHg3ye4RGDEZldQNgE HvAIEUdopZTTFqNUFQdrnAslj31wc1tJQxfGcGBMmnqXc+Ot2rnrG2dM/RXQ2CktClqzntoNa Nc7vAJ/8gNdt3o= Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 2021-11-23 at 09:13 +0000, Mel Gorman wrote: > On Sun, Nov 21, 2021 at 11:57:20AM +0100, Mike Galbraith wrote: > > Greetings, > > > > FYI, something in this series causes LTP controllers::memcg_regression > > testcase to hang forever.=C2=A0 Verified via brute force revert of the= lot. > > > > After letting box moan for 4.5 hours, I poked ^C repeatedly, but runlt= p > > didn't exit/recover gracefully, and ps hung, so I nuked the box.=C2=A0= All > > memcg_test_1 instances were stuck in reclaim_throttle(). > > > > I'll see can I reproduce this but do you know offhand what the test is > doing and what the expected outcome is? A possibility is that this is a > test that is driving the machine near OOM (or at least memcg OOM) and > getting throttled instead of getting killed. Here's the hanging test 4. testcases/bin/memcg_regression_test.sh: test_4() { ./memcg_test_4.sh check_kernel_bug if [ $? -eq 1 ]; then tst_resm TPASS "no kernel bug was found" fi # test_4.sh might be killed by oom, so do clean up here killall -9 memcg_test_4 2> /dev/null killall -9 memcg_test_4.sh 2> /dev/null # if test_4.sh gets killed, it won't clean cgroup it created rmdir memcg/0 2> /dev/null swapon -a } testcases/bin/memcg_test_4.sh: # attach current task to memcg/0/ mkdir memcg/0 echo $$ > memcg/0/tasks ./memcg_test_4 & pid=3D$! sleep 1 # let $pid allocate 100M memory /bin/kill -SIGUSR1 $pid sleep 1 # shrink memory, and then 80M will be swapped echo 40M > memcg/0/memory.limit_in_bytes # turn off swap, and swapoff will be killed swapoff -a sleep 1 echo $pid > memcg/tasks 2> /dev/null echo $$ > memcg/tasks 2> /dev/null # now remove the cgroup rmdir memcg/0