From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from dggsgout11.his.huawei.com (dggsgout11.his.huawei.com [45.249.212.51]) (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 DB87F1BC08F; Fri, 13 Feb 2026 02:06:06 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=45.249.212.51 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1770948370; cv=none; b=mtLAIg21gUxnlPz4YwFaw5NQfke9L93p9JKnZgrc5oRnmCkFB9JMZmeVUYpPNknd/Jmsa87fgeWgnA1iuqe1emq2X5khz1FaYZFIk0+2wkoQ0WH0OyEUuX/p6XQoo4Jou5a+x7HONKj32H2rUTx2ngnHGU+1KGFcHeDYb9jHM0I= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1770948370; c=relaxed/simple; bh=12eeLHIc3DHy19ev2jtTZ1HLGUHVMFbDU7A5ET9P3iU=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=awg0moJlkweWhigEE7K8zB+FenwH59s+s6xtL8X8K1cmCxJsSZshQH7/LxaXTecLDuuoPn1ApvoZstItbZobMA8qNVh0wqmmX/mZuzVH3pQET2YaLspRQ4Z/raDRwi6uBG10YL+3KcnGugV/dWj+fSx1RmUbuet8zWaGyD4XHa0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=huaweicloud.com; spf=pass smtp.mailfrom=huaweicloud.com; arc=none smtp.client-ip=45.249.212.51 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=huaweicloud.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=huaweicloud.com Received: from mail.maildlp.com (unknown [172.19.163.170]) by dggsgout11.his.huawei.com (SkyGuard) with ESMTPS id 4fBwWF3G8MzYQv0J; Fri, 13 Feb 2026 10:06:01 +0800 (CST) Received: from mail02.huawei.com (unknown [10.116.40.128]) by mail.maildlp.com (Postfix) with ESMTP id 24E624056B; Fri, 13 Feb 2026 10:06:04 +0800 (CST) Received: from [10.67.111.176] (unknown [10.67.111.176]) by APP4 (Coremail) with SMTP id gCh0CgBH8vIKh45p2kH4HA--.16745S2; Fri, 13 Feb 2026 10:06:03 +0800 (CST) Message-ID: <38c29e11-4e8a-4c3e-b6fc-7d86d49a4657@huaweicloud.com> Date: Fri, 13 Feb 2026 10:06:02 +0800 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v5 3/6] cgroup/cpuset: Set isolated_cpus_updating only if isolated_cpus is changed To: Waiman Long , Tejun Heo , Johannes Weiner , =?UTF-8?Q?Michal_Koutn=C3=BD?= , Ingo Molnar , Peter Zijlstra , Juri Lelli , Vincent Guittot , Steven Rostedt , Ben Segall , Mel Gorman , Valentin Schneider , Anna-Maria Behnsen , Frederic Weisbecker , Thomas Gleixner , Shuah Khan Cc: cgroups@vger.kernel.org, linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org References: <20260212164640.2408295-1-longman@redhat.com> <20260212164640.2408295-4-longman@redhat.com> Content-Language: en-US From: Chen Ridong In-Reply-To: <20260212164640.2408295-4-longman@redhat.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-CM-TRANSID:gCh0CgBH8vIKh45p2kH4HA--.16745S2 X-Coremail-Antispam: 1UD129KBjvJXoW7Zr4xGry7Ar17Ar4rAF15CFg_yoW8Xr43pr 18K347CFW5tF43C34aqwn2gr1Sgws5JrW2kay5Kr15ZFnxXa4vqw17W3Z8tr18Kws3Wry8 Ar9IgFs2ga4Ika7anT9S1TB71UUUUU7qnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDU0xBIdaVrnRJUUUv0b4IE77IF4wAFF20E14v26ryj6rWUM7CY07I20VC2zVCF04k2 6cxKx2IYs7xG6rWj6s0DM7CIcVAFz4kK6r1j6r18M28lY4IEw2IIxxk0rwA2F7IY1VAKz4 vEj48ve4kI8wA2z4x0Y4vE2Ix0cI8IcVAFwI0_tr0E3s1l84ACjcxK6xIIjxv20xvEc7Cj xVAFwI0_Gr1j6F4UJwA2z4x0Y4vEx4A2jsIE14v26rxl6s0DM28EF7xvwVC2z280aVCY1x 0267AKxVW0oVCq3wAS0I0E0xvYzxvE52x082IY62kv0487Mc02F40EFcxC0VAKzVAqx4xG 6I80ewAv7VC0I7IYx2IY67AKxVWUJVWUGwAv7VC2z280aVAFwI0_Jr0_Gr1lOx8S6xCaFV Cjc4AY6r1j6r4UM4x0Y48IcVAKI48JM4IIrI8v6xkF7I0E8cxan2IY04v7MxkF7I0En4kS 14v26r4a6rW5MxAIw28IcxkI7VAKI48JMxC20s026xCaFVCjc4AY6r1j6r4UMI8I3I0E5I 8CrVAFwI0_Jr0_Jr4lx2IqxVCjr7xvwVAFwI0_JrI_JrWlx4CE17CEb7AF67AKxVW8ZVWr XwCIc40Y0x0EwIxGrwCI42IY6xIIjxv20xvE14v26r1j6r1xMIIF0xvE2Ix0cI8IcVCY1x 0267AKxVW8JVWxJwCI42IY6xAIw20EY4v20xvaj40_Jr0_JF4lIxAIcVC2z280aVAFwI0_ Jr0_Gr1lIxAIcVC2z280aVCY1x0267AKxVW8JVW8JrUvcSsGvfC2KfnxnUUI43ZEXa7IU0 s2-5UUUUU== X-CM-SenderInfo: hfkh02xlgr0w46kxt4xhlfz01xgou0bp/ On 2026/2/13 0:46, Waiman Long wrote: > As cpuset is updating HK_TYPE_DOMAIN housekeeping mask when there is > a change in the set of isolated CPUs, making this change is now more > costly than before. Right now, the isolated_cpus_updating flag can be > set even if there is no real change in isolated_cpus. Put in additional > checks to make sure that isolated_cpus_updating is set only if there > is a real change in isolated_cpus. > > Signed-off-by: Waiman Long > --- > kernel/cgroup/cpuset.c | 10 +++++++--- > 1 file changed, 7 insertions(+), 3 deletions(-) > > diff --git a/kernel/cgroup/cpuset.c b/kernel/cgroup/cpuset.c > index e55855269432..c792380f9b60 100644 > --- a/kernel/cgroup/cpuset.c > +++ b/kernel/cgroup/cpuset.c > @@ -1180,11 +1180,15 @@ static void isolated_cpus_update(int old_prs, int new_prs, struct cpumask *xcpus > WARN_ON_ONCE(old_prs == new_prs); > lockdep_assert_held(&callback_lock); > lockdep_assert_held(&cpuset_mutex); > - if (new_prs == PRS_ISOLATED) > + if (new_prs == PRS_ISOLATED) { > + if (cpumask_subset(xcpus, isolated_cpus)) > + return; > cpumask_or(isolated_cpus, isolated_cpus, xcpus); > - else > + } else { > + if (!cpumask_intersects(xcpus, isolated_cpus)) > + return; > cpumask_andnot(isolated_cpus, isolated_cpus, xcpus); > - > + } > isolated_cpus_updating = true; > } > Reviewed-by: Chen Ridong -- Best regards, Ridong