From nobody Tue Feb 10 02:59:03 2026 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) (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 011492F3609 for ; Thu, 1 Jan 2026 19:16:16 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.129.124 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1767294978; cv=none; b=QKEixoubWThc+SqZLNNJxgO4N7rWMbMBpTXEY4u0+yG/T+FHAwLMHs5UywfEX/26j7QAJXZJcNMAJcfKGzjCwlvmlGYnVMN4JkLp3eEcYRGZSRpyzpmrTLZImNgzBPDyiuBCRJU2pXlsLzTksAPtNA5Z6n2ZUxVe+qgJILshYyU= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1767294978; c=relaxed/simple; bh=etlfhTemoygMQW3PHZe0HVBAQTnSuw8QQ3VegLsbQ4g=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=OTEC+JS+JuQnPRpKAk/7TZt8T8L9AmKjrUN62OhxODgtHHBJf1Vh3S2o9wVmnNZMW5q/LGrJ79HAjGPdrMbFscTpDXoGFLF01xfwW+/+JNdSEbsEgSb1/bI0+LzqYrHs70M/ROYRJuTWQ4ylufaenwX6lCsyLwMMGNCQrrf9hyU= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=emoKP5ja; arc=none smtp.client-ip=170.10.129.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="emoKP5ja" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1767294976; 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=Zrwy5CP+T+6ulQfCzu10r1dq1k5+JaVARRWBoOGzC1Y=; b=emoKP5jauY9Srfkz28Flz2v+fl5jBJj4ZJJZgE2LDB0esJ2gq1JL9VXDVAfWDSYySSbAON 0CLKLRY5BJDga5cC4N+77rwdQ2m4PEsJd8BDuOydW8TdYTG+V/UUBbr5Y/yTSLFP/H69+y hV2IDArh2yrIkKs4tj8Xfy5HeAbs5aU= 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-299-0E6WrBNvOsi-9cHN0063Eg-1; Thu, 01 Jan 2026 14:16:12 -0500 X-MC-Unique: 0E6WrBNvOsi-9cHN0063Eg-1 X-Mimecast-MFC-AGG-ID: 0E6WrBNvOsi-9cHN0063Eg_1767294971 Received: from mx-prod-int-03.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-03.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.12]) (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 B08AE195608A; Thu, 1 Jan 2026 19:16:10 +0000 (UTC) Received: from llong-thinkpadp16vgen1.westford.csb (unknown [10.22.88.71]) by mx-prod-int-03.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id 8ECB119560B4; Thu, 1 Jan 2026 19:16:08 +0000 (UTC) From: Waiman Long To: Tejun Heo , Johannes Weiner , =?UTF-8?q?Michal=20Koutn=C3=BD?= , Jonathan Corbet , Shuah Khan Cc: linux-kernel@vger.kernel.org, cgroups@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-doc@vger.kernel.org, Sun Shaojie , Chen Ridong , Waiman Long Subject: [cgroup/for-6.20 PATCH v2 1/4] cgroup/cpuset: Streamline rm_siblings_excl_cpus() Date: Thu, 1 Jan 2026 14:15:55 -0500 Message-ID: <20260101191558.434446-2-longman@redhat.com> In-Reply-To: <20260101191558.434446-1-longman@redhat.com> References: <20260101191558.434446-1-longman@redhat.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Scanned-By: MIMEDefang 3.0 on 10.30.177.12 Content-Type: text/plain; charset="utf-8" If exclusive_cpus is set, effective_xcpus must be a subset of exclusive_cpus. Currently, rm_siblings_excl_cpus() checks both exclusive_cpus and effective_xcpus consecutively. It is simpler to check only exclusive_cpus if non-empty or just effective_xcpus otherwise. No functional change is expected. Signed-off-by: Waiman Long Reviewed-by: Chen Ridong --- kernel/cgroup/cpuset.c | 24 +++++++++++++++--------- 1 file changed, 15 insertions(+), 9 deletions(-) diff --git a/kernel/cgroup/cpuset.c b/kernel/cgroup/cpuset.c index 221da921b4f9..da2b3b51630e 100644 --- a/kernel/cgroup/cpuset.c +++ b/kernel/cgroup/cpuset.c @@ -1355,23 +1355,29 @@ static int rm_siblings_excl_cpus(struct cpuset *par= ent, struct cpuset *cs, int retval =3D 0; =20 if (cpumask_empty(excpus)) - return retval; + return 0; =20 /* - * Exclude exclusive CPUs from siblings + * Remove exclusive CPUs from siblings */ rcu_read_lock(); cpuset_for_each_child(sibling, css, parent) { + struct cpumask *sibling_xcpus; + if (sibling =3D=3D cs) continue; =20 - if (cpumask_intersects(excpus, sibling->exclusive_cpus)) { - cpumask_andnot(excpus, excpus, sibling->exclusive_cpus); - retval++; - continue; - } - if (cpumask_intersects(excpus, sibling->effective_xcpus)) { - cpumask_andnot(excpus, excpus, sibling->effective_xcpus); + /* + * If exclusive_cpus is defined, effective_xcpus will always + * be a subset. Otherwise, effective_xcpus will only be set + * in a valid partition root. + */ + sibling_xcpus =3D cpumask_empty(sibling->exclusive_cpus) + ? sibling->effective_xcpus + : sibling->exclusive_cpus; + + if (cpumask_intersects(excpus, sibling_xcpus)) { + cpumask_andnot(excpus, excpus, sibling_xcpus); retval++; } } --=20 2.52.0