From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 07E9D2C027C; Fri, 20 Mar 2026 02:43:49 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773974630; cv=none; b=hrCiTkpPuTr9qSsuQwPkGtu96ziKTJo4gZv06yETx3ZYF8ahAQshDUOkV8Je8Af0cWa83AZJZrWmEz7Ft9tB9B0Eknk16pgva09l4MdfpMRrVhBtKNF/HCoFzdHm03INk3aH5zkT0ABiF32Fctnq/4D7/YZa5oVGPy91KT64lPE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773974630; c=relaxed/simple; bh=IM7odbRo5JmXvV35WSNt2mLDPESwML5Li6T+qlytX5s=; h=Date:From:To:Cc:Subject:Message-Id:In-Reply-To:References: Mime-Version:Content-Type; b=nQPA8YiT56h4P4rezfmazWnp7t5ZufgUcHPC71tCH2uedKtOxrDiPOF48lyo/A/jL8kjFVPPdr1oP+njC9DtnEZ4md6gqaZ5AZLigh6yeP9IdtkXfG8tTJ57du4SY2Q/gfcwZ5JK/po2eKHzKUJ1sz7zvL3J0fqmgG8kzJLJcQY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b=Hgkr4hg7; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b="Hgkr4hg7" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 46D87C19424; Fri, 20 Mar 2026 02:43:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1773974628; bh=IM7odbRo5JmXvV35WSNt2mLDPESwML5Li6T+qlytX5s=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=Hgkr4hg7zQXTt/YOkRxPkZIHUtK1zTNcywzH1MTqkkREzmi+9td5X05r118VG/gIv EUhIpque6aM/JP1B3c6Vr0hPdX5qI+jqzi3lt2YguscLplbGdsloC37l/N6PfVU0CG 3BB+Li1V5rF2Lm7aIiOKKHmYDkcoC8MS2OnOO6CE= Date: Thu, 19 Mar 2026 19:43:47 -0700 From: Andrew Morton To: Waiman Long Cc: Johannes Weiner , Michal Hocko , Roman Gushchin , Shakeel Butt , Muchun Song , Tejun Heo , Michal =?ISO-8859-1?Q?Koutn=FD?= , Shuah Khan , Mike Rapoport , linux-kernel@vger.kernel.org, cgroups@vger.kernel.org, linux-mm@kvack.org, linux-kselftest@vger.kernel.org, Sean Christopherson , James Houghton , Sebastian Chlad , Guopeng Zhang , Li Wang Subject: Re: [PATCH 0/7] selftests: memcg: Fix test_memcontrol test failures with large page sizes Message-Id: <20260319194347.1048fc8d737b6e8f9d82663d@linux-foundation.org> In-Reply-To: <20260319173752.1472864-1-longman@redhat.com> References: <20260319173752.1472864-1-longman@redhat.com> X-Mailer: Sylpheed 3.8.0beta1 (GTK+ 2.24.33; x86_64-pc-linux-gnu) Precedence: bulk X-Mailing-List: linux-kselftest@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit On Thu, 19 Mar 2026 13:37:45 -0400 Waiman Long wrote: > There are a number of test failures with the running of the > test_memcontrol selftest on a 128-core arm64 system on kernels with > 4k/16k/64k page sizes. This patch series makes some minor changes to > the kernel and the test_memcontrol selftest to address these failures. > > The first kernel patch scales the memcg vmstats flush threshold > logarithmetically instead of linearly with the total number of CPUs. The > second kernel patch scale down MEMCG_CHARGE_BATCH with increases in page > size. These 2 patches help to reduce the discrepancies between the > reported usage data with the real ones. > > The next 5 test_memcontrol selftest patches adjust the testing code to > greatly reduce the chance that it will report failure, though some > occasional failures is still possible. > > To verify the changes, the test_memcontrol selftest was run 100 > times each on a 128-core arm64 system on kernels with 4k/16k/64k > page sizes. No failure was observed other than some failures of the > test_memcg_reclaim test when running on a 16k page size kernel. The > reclaim_until() call failed because of the unexpected over-reclaim of > memory. This will need a further look but it happens with the 16k page > size kernel only and I don't have a production ready kernel config file > to use in buildinig this 16k page size kernel. The new test_memcontrol > selftest and kernel were also run on a 96-core x86 system to make sure > there was no regression. AI reviewbot asks questions: https://sashiko.dev/#/patchset/20260319173752.1472864-1-longman%40redhat.com