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 B26C1C433F5 for ; Mon, 22 Nov 2021 06:47:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232734AbhKVGuO (ORCPT ); Mon, 22 Nov 2021 01:50:14 -0500 Received: from mout.gmx.net ([212.227.17.21]:33481 "EHLO mout.gmx.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232560AbhKVGuH (ORCPT ); Mon, 22 Nov 2021 01:50:07 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=gmx.net; s=badeba3b8450; t=1637563611; bh=C6LIvmc696yIdTukGLDaZor0Z2/Ukm396tIyvEaAsfg=; h=X-UI-Sender-Class:Subject:From:To:Cc:Date:In-Reply-To:References; b=jQ6REg+4I80JoLJkgSalT8ad+oxxJOnJ9MhDAlubCdfTZszkes+5xAqeLS8FdSddg HVnBspflDfhap7v9WuZdCN0wqrU7iimJknBB3QO0plw+iu28tdgz2TszulO11xKiVL 1eVfvrG0ZW5S6xoWMoLQgW8aIJj3NCwN+bzNITjM= X-UI-Sender-Class: 01bb95c1-4bf8-414a-932a-4f6e2808ef9c Received: from homer.fritz.box ([185.191.216.218]) by mail.gmx.net (mrgmx104 [212.227.17.168]) with ESMTPSA (Nemesis) id 1M5QJJ-1mps342f1p-001UnP; Mon, 22 Nov 2021 07:46:51 +0100 Message-ID: <723736b7736da3810cab582dee4591fec063618b.camel@gmx.de> Subject: Re: mm: LTP/memcg testcase regression induced by 8cd7c588decf..66ce520bb7c2 series From: Mike Galbraith To: Thorsten Leemhuis , lkml , "regressions@lists.linux.dev" Cc: Mel Gorman Date: Mon, 22 Nov 2021 07:46:50 +0100 In-Reply-To: <6cc591c5-ed71-3213-3119-c778b3b2823d@leemhuis.info> References: <99e779783d6c7fce96448a3402061b9dc1b3b602.camel@gmx.de> <6cc591c5-ed71-3213-3119-c778b3b2823d@leemhuis.info> 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:LgTFEfLTW34s5E/9UQnKKGKkWuiSMJxzqz8SKD8VEZDVKkCDi4g giQQ+qjOZYM2SvbO9ZDmjIj3PA+Glbxac8eX2hdb/6v1NC1PoFRfff1YTiA4KEXrkA6joF5 30yxpDb9JwSLOAvAwCgRUPAZpXj1eWr2iGQjdyiHf3n8GRQt+HkkVVj/3COHse7hbjJALXl DxUkvtO8Jfp79WnFxAIjg== X-UI-Out-Filterresults: notjunk:1;V03:K0:ASGXN+dd1OM=:U4165REqhXYapPxWlx18uT 6QD3/3cUI+H8t9MA6x3azns+7tgsRKY6hygGkt8C1A2P4+7pN5FCcTYuMbyvhFezg8wTXnKoR bgJrp5SSAnJciotzqZOxD8bhuGokHRbWBpYdQEiGkyRbkr91ZDwHHDPwtS27oah6aicjYmekZ 0fR/dvqC4iCflDB+CD4poLeEHUusplVCuMmO763JNSpsDfkWEPmgO77+rrbbfwyB4vC/6BdyZ IFqYtHYbpf/bcWQbtqiJ+M4IHVCvSfOD0FyQB/BbGXhhyOWCCzPaEI9mTHwO485WMdsDe4ihE MweE2MC2356mqi7YCWr3zFKE9rzKfLlhEqBD5sfTQgevU5Y58wohsFvQPW0GmTXp9gdHc6mo4 YWbE7O/2oiy4Uu1yJTxRkQI1yEhB8IK0S2cSJhVEyW758FivyoraPXSkGYmu1L6QeC1y8Hcxf AFVM1UzdP4jp0dPX+/6/OIe7yrabliVz/4sBKJHOJkrj0hjNO7VHeESOUSMdnr55wpz9tkY1e dzX8ES4Mwq1fUxU9iRB2+LFKSQWfTd+sszsPIdEZL4tTXt1zbQ6RNrU1fqbvOCs68aQkFv0eA 64TaRGyK9DNmioYVVYDgqFfNLhnADaU4XaA7ywksbRLGDEZjVf91nmfpfmAvzmN7mcHPiHGZo /NRdyADLa+Ta0r74VWKCDhSp0wFExl23+vsfpeOIwegPfbGH0uK3iWKTqZ0GVqdY/VMvO7XgU eWTSXU8iR+aBDdaj1saNj/1mXfaNFKsO2BKYMd2q10kEVdVxHrnKFifKthYwwSk3kHY5kuhHw /zqcjCikb4/Q+BiKyyBpOaspZKRgaV8dUXYZp1KQxjSsobxs0SuRGuEyliMM1E1Mvjw0YVk4K 9bNKiVmhTolaUY5f2tx/hZn23d8QpsQE/7bLM/7RpKsPW3c7xRGxNVqlyJu2AdVvS8i0SIChQ IToq03dWWWdj4Nmjn/U7HB/fi7TJFoa0i1RJXhvSnSWrJme3adL//naIyiCqi20ucy4XsKJDe /ppMFu6AjBaTbvhObG8vVrMQIauCZL2/D4oirrs23D1gPHdq1nH7QaAo/mSTkxH6zIU3Bt/T0 kp6NnGcTZwXL+E= Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sun, 2021-11-21 at 14:51 +0100, Thorsten Leemhuis wrote: > > Hi, this is your Linux kernel regression tracker speaking. This isn't necessarily a kernel regression, though the fact that bystander tasks like ps can get snagged for ages as the testcase runs at an amazingly glacial pace doesn't look particularly wonderful. homer:/root # time ps lax ... real 11m33.258s user 0m0.004s sys 0m0.008s homer:/root # The other memcg tests complete fine, though taking more time to do so. Running all tests except memcg_regression, (and memcg_stress because it's a 30 minute swap storm from hell as delivered), runtime increased from 0m37s to 4m43s. The problematic testcase is root intentionally shooting its own foot, then checking for battle damage that occurred in days of yore, so it now hurting in a different way isn't necessarily grounds to gripe at the kernel.. even with the rather ugly side effects.. maybe . #-------------------------------------------------------------------------= -- # Bug: The bug was, while forking mass processes, trigger memcgroup OOM= , # then NULL pointer dereference may be hit. # Kernel: 2.6.25-rcX # Links: http://lkml.org/lkml/2008/4/14/38 # Fix: commit e115f2d89253490fb2dbf304b627f8d908df26f1 #-------------------------------------------------------------------------= -- test_1() { mkdir memcg/0/ echo 0 > memcg/0/memory.limit_in_bytes ./memcg_test_1 rmdir memcg/0/ check_kernel_bug if [ $? -eq 1 ]; then tst_resm TPASS "no kernel bug was found" fi } I'm gonna just comment the little bugger out as obsolete and walk away. -Mike