From patchwork Mon Apr 14 02:12:49 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Waiman Long X-Patchwork-Id: 14049604 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 CDFF6C369B1 for ; Mon, 14 Apr 2025 02:13:15 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 2C9EC280002; Sun, 13 Apr 2025 22:13:14 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 2784C280001; Sun, 13 Apr 2025 22:13:14 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 11784280002; Sun, 13 Apr 2025 22:13:14 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0014.hostedemail.com [216.40.44.14]) by kanga.kvack.org (Postfix) with ESMTP id E3B4F280001 for ; Sun, 13 Apr 2025 22:13:13 -0400 (EDT) Received: from smtpin26.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay05.hostedemail.com (Postfix) with ESMTP id C78035B901 for ; Mon, 14 Apr 2025 02:13:14 +0000 (UTC) X-FDA: 83331027108.26.C133F3C Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by imf30.hostedemail.com (Postfix) with ESMTP id 2752880009 for ; Mon, 14 Apr 2025 02:13:12 +0000 (UTC) Authentication-Results: imf30.hostedemail.com; dkim=pass header.d=redhat.com header.s=mimecast20190719 header.b=ak+zEDji; dmarc=pass (policy=quarantine) header.from=redhat.com; spf=pass (imf30.hostedemail.com: domain of longman@redhat.com designates 170.10.133.124 as permitted sender) smtp.mailfrom=longman@redhat.com ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1744596793; a=rsa-sha256; cv=none; b=jF3RyU+czE8MBMrBnn2ZsXqMW5OVhCrGnqthyjAQcJ7iqv7bb2NVuScYyLf24oncqhlbcs PZVg0m4Cj0am23RyNoixJM3y3cypPYPFOFIMGkzgKTCBfcQFvjonica/WPEsdjwFlI27SF vlvdQaG8nk7FHsivdQycnwWco05LRL4= ARC-Authentication-Results: i=1; imf30.hostedemail.com; dkim=pass header.d=redhat.com header.s=mimecast20190719 header.b=ak+zEDji; dmarc=pass (policy=quarantine) header.from=redhat.com; spf=pass (imf30.hostedemail.com: domain of longman@redhat.com designates 170.10.133.124 as permitted sender) smtp.mailfrom=longman@redhat.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1744596793; 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=cWd3wodO+vJYf6OkqNBmP1cg6W0V7cLt+fJ3yVah9lQ=; b=bgF8HJY24l7UKaJFgl+iUwWoj8nj36zXlGjWAs0DLD1iWh0iGwCvJKqz781/weul3QGhl/ 5fwvVQ1N4THlvIn5ZiXFB2+VxtWsl4WZ35qVOfCT9vPtBNjF2DzV6mIor+qGEjLLeeByMw p9u66UG0RRU0KRhDjNMjLyr+2FGGxFc= DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1744596792; 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=cWd3wodO+vJYf6OkqNBmP1cg6W0V7cLt+fJ3yVah9lQ=; b=ak+zEDjivs6H30+S15m04Nm2fPERmwb+s2vvt72gv7IqZz9W3Dr55KpGM0Wor9E9mJh7/P 5qu/SaXFbf3VJN6hHI4Sc6XN2ZM3tVc39h3CD6X5avyt1EDpTZoPKPLCbFAzygck5aeSAY qBbSu2Tftefy81b6bZ6mFtwJvXX/IBw= Received: from mx-prod-mc-04.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-500-iG2B4VqjNJyB-FSbxmYGvw-1; Sun, 13 Apr 2025 22:13:09 -0400 X-MC-Unique: iG2B4VqjNJyB-FSbxmYGvw-1 X-Mimecast-MFC-AGG-ID: iG2B4VqjNJyB-FSbxmYGvw_1744596787 Received: from mx-prod-int-06.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-06.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.93]) (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-04.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id CCF5D1955DC5; Mon, 14 Apr 2025 02:13:06 +0000 (UTC) Received: from llong-thinkpadp16vgen1.westford.csb (unknown [10.22.88.48]) by mx-prod-int-06.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id 11E63180B488; Mon, 14 Apr 2025 02:13:02 +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 v6 2/2] selftests: memcg: Increase error tolerance of child memory.current check in test_memcg_protection() Date: Sun, 13 Apr 2025 22:12:49 -0400 Message-ID: <20250414021249.3232315-3-longman@redhat.com> In-Reply-To: <20250414021249.3232315-1-longman@redhat.com> References: <20250414021249.3232315-1-longman@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.4.1 on 10.30.177.93 X-Rspamd-Queue-Id: 2752880009 X-Stat-Signature: e1jif1y9aeksdk9whfpkohrgies9bmuj X-Rspam-User: X-Rspamd-Server: rspam06 X-HE-Tag: 1744596792-8187 X-HE-Meta: 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 ThFVWOo2 m0DaKMOy0mzy9FmCyhSUvjsrJ1mBGVp1TcN1XNCuJo81t/Jq418nbD6EetyHKfeqPkJI50kysIxkwpchr+Q0a5QZiRCrF9KnMPc2nYMC/gp2dUkSmxUPixem6SesHpBe+eO/B9NVK9P02u3eFU9m6i9P5+waS2kKpOnnxs8LBlRekT/KV4hP5PKreyP9Sh18Har0VeHf+jRr6yuaGRhWT3eXKgP/kcWOh5tMAMUGnhHS1kwGzwSk7r8lwKY8ZcJCtIumwTOEvHJhBlgIbi6pG5Y/n+hItK5r9mxmmku556Gz/BK81is5GI+dk4zteXoTeZzAifg1+ysERQPCaPglsdjL2UZi9RwobvjVjIr0Us9UOTd1dOYkJgwx/G2D9MdP89lrh 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. However, these tests may still fail once in a while if the memory usage goes beyond the newly extended range. 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 5a5dcbe57b56..2ef07b8fa718 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)