From patchwork Mon Apr 7 01:41:59 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Waiman Long X-Patchwork-Id: 14039636 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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 9C104C36002 for ; Mon, 7 Apr 2025 01:42:23 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id E8A296B0010; Sun, 6 Apr 2025 21:42:22 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id E15626B0011; Sun, 6 Apr 2025 21:42:22 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id C8BA46B0012; Sun, 6 Apr 2025 21:42:22 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0013.hostedemail.com [216.40.44.13]) by kanga.kvack.org (Postfix) with ESMTP id A537E6B0010 for ; Sun, 6 Apr 2025 21:42:22 -0400 (EDT) Received: from smtpin14.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay06.hostedemail.com (Postfix) with ESMTP id 7F96AB9DE0 for ; Mon, 7 Apr 2025 01:42:22 +0000 (UTC) X-FDA: 83305547724.14.91C49B1 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by imf16.hostedemail.com (Postfix) with ESMTP id F1D76180005 for ; Mon, 7 Apr 2025 01:42:20 +0000 (UTC) Authentication-Results: imf16.hostedemail.com; dkim=pass header.d=redhat.com header.s=mimecast20190719 header.b=fTmitZCa; spf=pass (imf16.hostedemail.com: domain of longman@redhat.com designates 170.10.129.124 as permitted sender) smtp.mailfrom=longman@redhat.com; dmarc=pass (policy=quarantine) header.from=redhat.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1743990141; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=0rjm7dsKH5H2OCApAESFBB2zqcpPfQudn9jh6O3bk7c=; b=Afi1ulEqffiw9kgWcHdx4sJE4elHHcXTK2tH4vC0XNDNvoNCgsAr36WoxdoONeLUPD5djC uhuAsT9DeTgtUK6jlbFXN0VY2jv3p3N24eVN2bH6XVVkNGyG83tqdgtDhu3K6d8YBiZm9i j90lgAI0pkxCpaWXgXLZFxiym1ZGs/U= ARC-Authentication-Results: i=1; imf16.hostedemail.com; dkim=pass header.d=redhat.com header.s=mimecast20190719 header.b=fTmitZCa; spf=pass (imf16.hostedemail.com: domain of longman@redhat.com designates 170.10.129.124 as permitted sender) smtp.mailfrom=longman@redhat.com; dmarc=pass (policy=quarantine) header.from=redhat.com ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1743990141; a=rsa-sha256; cv=none; b=fgCDxqZsJVfJ71p/Wc/DgXO2au1mBTMLdUxKPf/zoJYUZNvSc6mPIXBzaMqDWeb6VMK54B oWH7O7Yv4Zhb44DvE2wmPZ07TMNYRec6RLNrlpnktI+EvDehDv5olABb3f4lfY3LTRjTR6 R9DU1IP++r0D92wBlAJmC5tklP6d2ZM= DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1743990140; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=0rjm7dsKH5H2OCApAESFBB2zqcpPfQudn9jh6O3bk7c=; b=fTmitZCaD3UA6BjcVciqea1a5hu7uOuLIdHEU28fEZmI0jSMav1AWqa/D43tEHdY5yVLvk 1l39dRkh8IGGtkyYghtynnzd3rgFJkfWYQG9sSa+qzBJScwa0lk8b7tMplXJyXdlAckeg4 /zTzk+JGPsureDfNXgIDI0+1WVchwPg= Received: from mx-prod-mc-05.mail-002.prod.us-west-2.aws.redhat.com (ec2-54-186-198-63.us-west-2.compute.amazonaws.com [54.186.198.63]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-509-kBu9596lMQO1DnNWBYEOew-1; Sun, 06 Apr 2025 21:42:17 -0400 X-MC-Unique: kBu9596lMQO1DnNWBYEOew-1 X-Mimecast-MFC-AGG-ID: kBu9596lMQO1DnNWBYEOew_1743990135 Received: from mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.111]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-05.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 235C41956080; Mon, 7 Apr 2025 01:42:15 +0000 (UTC) Received: from llong-thinkpadp16vgen1.westford.csb (unknown [10.22.64.92]) by mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id 555181801766; Mon, 7 Apr 2025 01:42:12 +0000 (UTC) From: Waiman Long To: Johannes Weiner , Michal Hocko , Roman Gushchin , Shakeel Butt , Muchun Song , Andrew Morton , Tejun Heo , =?utf-8?q?Michal_Koutn=C3=BD?= , Shuah Khan Cc: linux-kernel@vger.kernel.org, cgroups@vger.kernel.org, linux-mm@kvack.org, linux-kselftest@vger.kernel.org, Waiman Long Subject: [PATCH v4 2/2] selftests: memcg: Increase error tolerance of child memory.current check in test_memcg_protection() Date: Sun, 6 Apr 2025 21:41:59 -0400 Message-ID: <20250407014159.1291785-3-longman@redhat.com> In-Reply-To: <20250407014159.1291785-1-longman@redhat.com> References: <20250407014159.1291785-1-longman@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.4.1 on 10.30.177.111 X-Rspamd-Queue-Id: F1D76180005 X-Stat-Signature: 4e3fd4mw3rdom7kxyii355mqdxkwzjnd X-Rspam-User: X-Rspamd-Server: rspam12 X-HE-Tag: 1743990140-641006 X-HE-Meta: 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 ISi6vefA eUB8DVUkRMUseEF1FtB8j47oZEP0NKZyE0I2uJhJFYYBEsJlRD0uW1POv49uuRp1izWl8/F6HV0QU5ztC+4sKleDCe9ve2Lj1EcqayMMVkuZJUaI= X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: The test_memcg_protection() function is used for the test_memcg_min and test_memcg_low sub-tests. This function generates a set of parent/child cgroups like: parent: memory.min/low = 50M child 0: memory.min/low = 75M, memory.current = 50M child 1: memory.min/low = 25M, memory.current = 50M child 2: memory.min/low = 0, memory.current = 50M After applying memory pressure, the function expects the following actual memory usages. parent: memory.current ~= 50M child 0: memory.current ~= 29M child 1: memory.current ~= 21M child 2: memory.current ~= 0 In reality, the actual memory usages can differ quite a bit from the expected values. It uses an error tolerance of 10% with the values_close() helper. Both the test_memcg_min and test_memcg_low sub-tests can fail sporadically because the actual memory usage exceeds the 10% error tolerance. Below are a sample of the usage data of the tests runs that fail. Child Actual usage Expected usage %err ----- ------------ -------------- ---- 1 16990208 22020096 -12.9% 1 17252352 22020096 -12.1% 0 37699584 30408704 +10.7% 1 14368768 22020096 -21.0% 1 16871424 22020096 -13.2% The current 10% error tolerenace might be right at the time test_memcontrol.c was first introduced in v4.18 kernel, but memory reclaim have certainly evolved quite a bit since then which may result in a bit more run-to-run variation than previously expected. Increase the error tolerance to 15% for child 0 and 20% for child 1 to minimize the chance of this type of failure. The tolerance is bigger for child 1 because an upswing in child 0 corresponds to a smaller %err than a similar downswing in child 1 due to the way %err is used in values_close(). Before this patch, a 100 test runs of test_memcontrol produced the following results: 17 not ok 1 test_memcg_min 22 not ok 2 test_memcg_low After applying this patch, there were no test failure for test_memcg_min and test_memcg_low in 100 test runs. Signed-off-by: Waiman Long --- tools/testing/selftests/cgroup/test_memcontrol.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/tools/testing/selftests/cgroup/test_memcontrol.c b/tools/testing/selftests/cgroup/test_memcontrol.c index bab826b6b7b0..8f4f2479650e 100644 --- a/tools/testing/selftests/cgroup/test_memcontrol.c +++ b/tools/testing/selftests/cgroup/test_memcontrol.c @@ -495,10 +495,10 @@ static int test_memcg_protection(const char *root, bool min) for (i = 0; i < ARRAY_SIZE(children); i++) c[i] = cg_read_long(children[i], "memory.current"); - if (!values_close(c[0], MB(29), 10)) + if (!values_close(c[0], MB(29), 15)) goto cleanup; - if (!values_close(c[1], MB(21), 10)) + if (!values_close(c[1], MB(21), 20)) goto cleanup; if (c[3] != 0)