From nobody Wed Apr 1 11:17:53 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 931E8401A33 for ; Tue, 31 Mar 2026 15:11:24 +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=1774969885; cv=none; b=TiXRI4XtD/3Hrp8Uqzpd5ThIDuI1OW+zyeof5DEJ4IRYk9LMS5uCRm9t9t2xvEqjwiy/AjahaUmmfO+iCmA98KT4Vu6zN5AXJKNKPDr1KJ0TKGkXqqs2jDfdszenNb16uHOqDQBImXvYLRG4QZGSj6AD7zpNYgtHrMWvAWWR2K4= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774969885; c=relaxed/simple; bh=gdTMaxVewZevxekZoWFMV5QbPBw4+0c6ISVvV4ELeaw=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=pZOlnXccOncuDah1XwYPjBfP7UPQjv7heeW2NaRZ1W/QgVotc8VZ0U+c21tBJGw/hDp/zY2MDCpy43PwX6Kaa1hSzLOwle1RUC4J5SL4Yey5jQ6jC2MXgIQVg847oFVDwe0kTmAz6L5dCk3koC/w6LbiZH+WB6zG31shWJfrYCk= 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=eC5johSj; 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="eC5johSj" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1774969883; 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=23vwVawhhdaUlEZbOs+YhGbbQr0Na89/CEeqFQu0cCc=; b=eC5johSjj/uazjGmg2siHJqYOQyww4hhluqTExR8lKFBmjs0H9eOlkOwjdSv5bzp5KdyC/ jVGUOqwlCAxZ2+IHuHdTXs5AiTpKyBJ1k2DFzA1J7O/rV+eYEcHKFsrYMMGcE8XZwDNCQb Z+5zPH9GpWnZUZqF3wxpistmLqdX6uQ= 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-547-1Qj2AIuhN5y31-AmD4Qdbg-1; Tue, 31 Mar 2026 11:11:17 -0400 X-MC-Unique: 1Qj2AIuhN5y31-AmD4Qdbg-1 X-Mimecast-MFC-AGG-ID: 1Qj2AIuhN5y31-AmD4Qdbg_1774969875 Received: from mx-prod-int-05.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-05.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.17]) (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 C413019560A6; Tue, 31 Mar 2026 15:11:15 +0000 (UTC) Received: from llong-thinkpadp16vgen1.westford.csb (unknown [10.22.80.26]) by mx-prod-int-05.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id 75B601954102; Tue, 31 Mar 2026 15:11:14 +0000 (UTC) From: Waiman Long To: Chen Ridong , Tejun Heo , Johannes Weiner , =?UTF-8?q?Michal=20Koutn=C3=BD?= Cc: cgroups@vger.kernel.org, linux-kernel@vger.kernel.org, Waiman Long Subject: [PATCH v3 1/2] cgroup/cpuset: Simplify setsched decision check in task iteration loop of cpuset_can_attach() Date: Tue, 31 Mar 2026 11:11:07 -0400 Message-ID: <20260331151108.2771560-2-longman@redhat.com> In-Reply-To: <20260331151108.2771560-1-longman@redhat.com> References: <20260331151108.2771560-1-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 10.30.177.17 Content-Type: text/plain; charset="utf-8" Centralize the check required to run security_task_setscheduler() in the task iteration loop of cpuset_can_attach() outside of the loop as it has no dependency on the characteristics of the tasks themselves. There is no functional change. Signed-off-by: Waiman Long --- kernel/cgroup/cpuset.c | 19 ++++++++++--------- 1 file changed, 10 insertions(+), 9 deletions(-) diff --git a/kernel/cgroup/cpuset.c b/kernel/cgroup/cpuset.c index d21868455341..58c5b7b72cca 100644 --- a/kernel/cgroup/cpuset.c +++ b/kernel/cgroup/cpuset.c @@ -2988,7 +2988,7 @@ static int cpuset_can_attach(struct cgroup_taskset *t= set) struct cgroup_subsys_state *css; struct cpuset *cs, *oldcs; struct task_struct *task; - bool cpus_updated, mems_updated; + bool setsched_check; int ret; =20 /* used later by cpuset_attach() */ @@ -3003,20 +3003,21 @@ static int cpuset_can_attach(struct cgroup_taskset = *tset) if (ret) goto out_unlock; =20 - cpus_updated =3D !cpumask_equal(cs->effective_cpus, oldcs->effective_cpus= ); - mems_updated =3D !nodes_equal(cs->effective_mems, oldcs->effective_mems); + /* + * Skip rights over task setsched check in v2 when nothing changes, + * migration permission derives from hierarchy ownership in + * cgroup_procs_write_permission()). + */ + setsched_check =3D !cpuset_v2() || + !cpumask_equal(cs->effective_cpus, oldcs->effective_cpus) || + !nodes_equal(cs->effective_mems, oldcs->effective_mems); =20 cgroup_taskset_for_each(task, css, tset) { ret =3D task_can_attach(task); if (ret) goto out_unlock; =20 - /* - * Skip rights over task check in v2 when nothing changes, - * migration permission derives from hierarchy ownership in - * cgroup_procs_write_permission()). - */ - if (!cpuset_v2() || (cpus_updated || mems_updated)) { + if (setsched_check) { ret =3D security_task_setscheduler(task); if (ret) goto out_unlock; --=20 2.53.0