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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id D7DE9C5AC67 for ; Thu, 6 Aug 2026 18:25:12 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id F1CFA6B008A; Thu, 6 Aug 2026 14:25:11 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id EF40F6B0098; Thu, 6 Aug 2026 14:25:11 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id E0D426B0099; Thu, 6 Aug 2026 14:25:11 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0017.hostedemail.com [216.40.44.17]) by kanga.kvack.org (Postfix) with ESMTP id B27F86B008A for ; Thu, 6 Aug 2026 14:25:11 -0400 (EDT) Received: from smtpin03.hostedemail.com (lb01a-stub [10.200.18.249]) by unirelay01.hostedemail.com (Postfix) with ESMTP id 3A70D1C01B4 for ; Thu, 6 Aug 2026 18:25:11 +0000 (UTC) X-FDA: 85071671622.03.CB8E853 Received: from mail-pj1-f53.google.com (mail-pj1-f53.google.com [209.85.216.53]) by imf12.hostedemail.com (Postfix) with ESMTP id 671B54000B for ; Thu, 6 Aug 2026 18:25:09 +0000 (UTC) Authentication-Results: imf12.hostedemail.com; dkim=pass header.d=gmail.com header.s=20251104 header.b=Gt7b3Vqw; spf=pass (imf12.hostedemail.com: domain of ziyang.meme@gmail.com designates 209.85.216.53 as permitted sender) smtp.mailfrom=ziyang.meme@gmail.com; dmarc=pass (policy=none) header.from=gmail.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1786040709; 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-type:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=eRxIpMxQf2eH73MswyccHSNChNNfT/J5n/NCnkKxEHE=; b=51uCKeaGEgmazCicekC7VMcO6myqbtylm0dcy6oigVGTnaH9qyXZp+QJuonyGPYNN9aztH KqGR/JKn5+l03KdSlob52AzcbosX0GqJcHenbzrJBY6BRtL5uS0e9XUhHm/yzMOZiwDI4E 1Urjo9ZE756bRpGXct6Hm+n26KQaJIU= ARC-Seal: i=1; a=rsa-sha256; d=hostedemail.com; s=arc-20220608; cv=none; t=1786040709; b=0vNkIpujG8GauiEBMHaesJ47N8BV+rrecqZicqRuOvF4ZDn8CxGQImjOG0Tm7o0cCQJm1c QPBSA3lJYsjP82aA+hEvw5gXMloTPCepIw7fs6aXxBV7HV0jB06/i3t9VAmFZTl7ej53KW oV6nbbd3/oLtOfqjXyeaN0fR7K9+6Is= ARC-Authentication-Results: i=1; imf12.hostedemail.com; dkim=pass header.d=gmail.com header.s=20251104 header.b=Gt7b3Vqw; spf=pass (imf12.hostedemail.com: domain of ziyang.meme@gmail.com designates 209.85.216.53 as permitted sender) smtp.mailfrom=ziyang.meme@gmail.com; dmarc=pass (policy=none) header.from=gmail.com Received: by mail-pj1-f53.google.com with SMTP id 98e67ed59e1d1-38e42560ebcso2199053a91.1 for ; Thu, 06 Aug 2026 11:25:09 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20251104; t=1786040708; x=1786645508; darn=kvack.org; h=in-reply-to:content-disposition:content-type:mime-version :references:message-id:subject:cc:to:from:date:from:to:cc:subject :date:message-id:reply-to:content-type; bh=eRxIpMxQf2eH73MswyccHSNChNNfT/J5n/NCnkKxEHE=; b=Gt7b3VqwtT5FxesIfDfdNRg/IAvxXa6wNpzFmJ5Oea8f6MmZxA7/yqxgee+/TjfKiK c5zsyZI0u6vURJ9IStfFxV7bfjlpIhoxGQYciXjVNqR5aiLU7A/1eZYjx7gVLh4FZBHs X8+eDcBU/YVgdcKSxAo3M3HZyh7qrXvOs1UGVlWgbO4Ip+2g1x7DbrI7oiYIW7otvC/Q Rfb5zcDatFkU/SKQ/UJHAlcahy7SGIIKddVFeEN4BSynwUIVoclHiVm8MO9O8HmsCZq0 YBwv7o0x2kygBqebNECu1HVibTPXISonm26MCVRz1gDb4dhVZVYYwX2u9/XEFdf+R3zA /PzQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1786040708; x=1786645508; h=in-reply-to:content-disposition:content-type:mime-version :references:message-id:subject:cc:to:from:date:x-gm-gg :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to :content-type; bh=eRxIpMxQf2eH73MswyccHSNChNNfT/J5n/NCnkKxEHE=; b=SHvKzDGSI3J5dFXO7Eb9CSKiugqevlO1NLGa7mqW//jUx5QHUhMhRiU9RMRAcg2DUU FjI8QnJDJgGndWOicv/BUljP4iO6cSpeqzRutqfh5IlNRsHkqHpMmbGupiuP5korCeEB JeYzU/qmlGVDheHymWYqzTzNhFAZe+ZRfgikEN7FO9hkhxHT5r0rw8pCwNCcHEDUFve2 K4Qw9J8WBt/K/wWRdjnCf6laPLaHA8JpWzzW325+iLAdDPLX+AjW6gIos+o9u5XXocHY bfhqT3dm0a7AQK7Ol3fd05QL5JY257D+DsBLRJwCroVYUm/pCuiB9yqHZKVJrPSrdfAR bw8A== X-Forwarded-Encrypted: i=1; AHgh+RrG5gMG/TTYbnZTw1r61JPvH4BbRJHLhqpEAhKwYmqmApqIqqjmKrqR2FHhpT/+Py7dtdE5eXzx+w==@kvack.org X-Gm-Message-State: AOJu0YxV7NUqFoLrw4PaJ3THTRGsY9ZP9UBJe/6BN/VsXlcxVZ64YkGr p17Dkw8KAkzTRbj04Q2Ys08neVykGecDkpzFeV+Ov6SxPz3XXsAVnSCV X-Gm-Gg: AR+sD12kD4zUVBwU+EXYZ5NPcGQyTeS9TY1eQMRQvBjGuH9154iuAWLKf2C6z6RtyWY jwoxdz7aV11EZvRRTDmSFpmJaLGOfJTE+Puq5quEKOY7OJHTjqU1atM0lif4WI4fnd1hNtN6w/D i6jyQKgzuVmxtTn+NX6o1kwKMdlKQ/jfwfdSOrMLL7o3FOff2u1XNENUwKN0HDHkTv1ytIbOYto KUCf919B+ydhhWRWiHF6+rs5xUI9caAArndzlvTaoFbWgdQuFTRmxdjQFpuwHHfNJAXFhZwULAs SDjTgrizQtV5vZpIlPidUxwehmSzglSZ1Hb9BdewrKh6r5c5H4Oyy/fA6Oq/wAoB/advTKj7ZZ8 Eh3ADS1lAaxpUKPZGn1fo3iOWTQWsuG8STz1c0Qw1afS5lzGbn/fjUprRtSSENIV+A9lumBooAW YMlbHplsnhsdy79O/IuC1bVi/hc/CwOMSWc5JBka+/Y2aD0STU+ZfTGzF86iIq5pdKURRTmGYDe gIiRqBT X-Received: by 2002:a17:90b:3889:b0:381:973e:fa08 with SMTP id 98e67ed59e1d1-3903c5cfba2mr14353244a91.18.1786040708017; Thu, 06 Aug 2026 11:25:08 -0700 (PDT) Received: from devvm16600.scu0.facebook.com ([2a03:2880:9ff:6e::]) by smtp.gmail.com with ESMTPSA id 5a478bee46e88-315867bc261sm29668669eec.28.2026.08.06.11.25.06 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 06 Aug 2026 11:25:07 -0700 (PDT) Date: Thu, 6 Aug 2026 11:25:04 -0700 From: Ziyang Men To: JP Kobryn Cc: Shuah Khan , Tejun Heo , Johannes Weiner , Michal =?iso-8859-1?Q?Koutn=FD?= , Jiri Kosina , Benjamin Tissoires , David Vernet , Eduard Zingerman , Andrea Righi , Changwoo Min , Michal Hocko , Roman Gushchin , Shakeel Butt , Muchun Song , Andrew Morton , Mykola Lysenko , Nathan Chancellor , linux-kselftest@vger.kernel.org, cgroups@vger.kernel.org, linux-input@vger.kernel.org, sched-ext@lists.linux.dev, linux-mm@kvack.org, kernel-team@meta.com, bpf@vger.kernel.org, llvm@lists.linux.dev, linux-kernel@vger.kernel.org Subject: Re: [PATCH v2 2/4] selftests/cgroup: add memcg_stat_cross_cpu correctness test for flush Message-ID: References: <20260721174833.1232771-1-ziyang.meme@gmail.com> <20260721174833.1232771-3-ziyang.meme@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii; format=flowed Content-Disposition: inline In-Reply-To: X-Rspamd-Queue-Id: 671B54000B X-Rspamd-Server: rspam10 X-Rspam-User: X-Stat-Signature: xpnwgpi41txz9p3scixfxjt1giqemhx5 X-HE-Tag: 1786040709-54353 X-HE-Meta: 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 Kn0YQv3e 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 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Wed, Jul 22, 2026 at 11:42:58AM -0700, JP Kobryn wrote: >On 7/21/26 10:48 AM, Ziyang Men wrote: >>Add a test_progs selftest that verifies the memory-cgroup BPF kfuncs >>return values that agree with what userspace reads from cgroupfs, across >>a whole cgroup subtree that has been charged on many CPUs. >> >>It complements the existing cgroup_iter_memcg test. cgroup_iter_memcg >>calls the memcg kfuncs on a single cgroup (BPF_CGROUP_ITER_SELF_ONLY) and >>only asserts each value is greater than zero, so it never checks that a >>value is actually correct. This test compares the kfunc values against >>what userspace reads from memory.stat, and checks every node in the >>cgroup tree. >> >Can you extend the existing test instead of adding a new one? Hi JP, Good suggestion. Actually extending the exisiting one was the plan in the v1. However, existing selftests with similar purpose is the cgroup_iter_memcg, which is in the bpf/. After discussed with the bpf reviewer in v1, we think this selftest may suit better in the cgroup/ rather than the bpf/, since 1) it tests the cgroup functionalities (bpf is a tool), and 2) together with the selftest, this patch serials also ships a common Makefile lib.bpf.mk for easily compiling selftests for other subsystems using bpf. Currently there is no other selftests in cgroup/ relies on BPF and we think it is good to put this selftest here as the first consumer. We appreciate any possible suggestions. Thanks very much! Best, Ziyang