From nobody Sun Feb 8 23:24:38 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 88F47363C7E for ; Mon, 12 Jan 2026 16:01:08 +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=1768233670; cv=none; b=TC5rvohl8FVKFMMlIQUf2PjLt1LhL8tOmylnBKUm6f82+gwlDxKN2A5qiN72wsndGvnONVTUALvrtnCofaHtvns8b4KdwoGclOv0pDwq4ZYTgOs16xjobsmbCmboOP9QqazeMxEyM8skuxMex3QOPNbegOh6OeDtTm8hIl+ZfYc= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1768233670; c=relaxed/simple; bh=/Hr5td0q2fKUO8L0UFsfzO/yV0xkttzaHGLMqqbjcaA=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=c0uoPMZUOwAeU+m0NhlFhlrM7AmDgMaMvLMclj8BbqifhXm3muM2IbHOJfH1aeFbsMygdIcLsKiIeTkPddzojFva3FxO7BJEG/2FSD112SatbGmBElnMwcbTAfQPTn6ISwuWZnHUyBGoWNOkD9BGok27Q9OpkHaIcWIVNGs8DX8= 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=NqSeYKOw; 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="NqSeYKOw" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1768233667; 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=B2dX1nduvd1Y2+YZKFwl6uVgXF8yg4bmyS1EUMGzFdk=; b=NqSeYKOwPPVWrJMg8MM4vc1mMN9hecBFs9LYccq0XePADHaA9byJS6UHFgg32w33cLxiup lwcRTZENkDI4UGxVvytYE649pq2ql2yuETSPzU1kq0V58tYj4cGXsBMEUPiiyT6BT9ph7/ RjWJiVhxW4ZUty1wVm3JkOMOGmx1qKU= 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-75-adJYnnBANv61u0nF6HBMIw-1; Mon, 12 Jan 2026 11:01:05 -0500 X-MC-Unique: adJYnnBANv61u0nF6HBMIw-1 X-Mimecast-MFC-AGG-ID: adJYnnBANv61u0nF6HBMIw_1768233663 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 398D51955E8C; Mon, 12 Jan 2026 16:01:01 +0000 (UTC) Received: from llong-thinkpadp16vgen1.westford.csb (unknown [10.22.89.95]) by mx-prod-int-03.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id 3A13619560B2; Mon, 12 Jan 2026 16:00:58 +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 , Chen Ridong Subject: [PATCH cgroup/for-6.20 v5 1/5] cgroup/cpuset: Streamline rm_siblings_excl_cpus() Date: Mon, 12 Jan 2026 11:00:17 -0500 Message-ID: <20260112160021.483561-2-longman@redhat.com> In-Reply-To: <20260112160021.483561-1-longman@redhat.com> References: <20260112160021.483561-1-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