From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) (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 D38F432C8B for ; Sat, 16 May 2026 04:25:24 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.133.124 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778905526; cv=none; b=XWy/LZW82a+ri+HMqhQE1C3e34WnwijgAQXdPa2i7x2rkV7D8TVtRDVD7ag4DRIKWXFdL2dYsvkh2J+X5luu8UTgPy3UAWqW1ZBQ1GrakNwqNKKGk6QQq5EdazTYVWf/+Nd76D3UxYpnYkspdPaaQ9sI575lhmXdGczjZHbJr+U= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778905526; c=relaxed/simple; bh=7GhbxdSY7+sfNr9B19nBc/YPJyog7BtsacD5usebgTg=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=ZObqPrsPUa5NNQn7GF6HONNktbj8Oi6zMXlwWPBNjaT0GJmFdkXJWMvrYpf5nkHjtq/oWg6gAxlcWR7ThAEkdJMhdacyyFch6JKIM7jpGy1IIOCwp3Is087C5hxtYzigDLGcmepqGRSWVBLeBOiHXnrjIQFzNkQi60jpUJSt9Nw= 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=Pjkxbbf9; arc=none smtp.client-ip=170.10.133.124 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="Pjkxbbf9" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1778905523; 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=3vjyTSbf1KtAbtYJwAX+RB0XaZHDboatGaFSQtnfftE=; b=Pjkxbbf9mORmqrydjbb9YC+okblA0rqfVoHOmbqFkLZY7/MSJvSpSzxsihE1zxWZz+Wsj1 e8A01vSW5jQvL5oVhdxD5uYagippJGk9XlDnw2jaLcyX78lJPzFmvip04aCk6//OmEyeBe T+Kx6TuSi4MoL6q61DwvUS1cBbx8HzE= Received: from mx-prod-mc-08.mail-002.prod.us-west-2.aws.redhat.com (ec2-35-165-154-97.us-west-2.compute.amazonaws.com [35.165.154.97]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-650-wo-uFs6SOmmStEBSYOot4g-1; Sat, 16 May 2026 00:25:19 -0400 X-MC-Unique: wo-uFs6SOmmStEBSYOot4g-1 X-Mimecast-MFC-AGG-ID: wo-uFs6SOmmStEBSYOot4g_1778905517 Received: from mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.111]) (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-08.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id AFA641800367; Sat, 16 May 2026 04:25:16 +0000 (UTC) Received: from llong-thinkpadp16vgen1.westford.csb (unknown [10.2.16.156]) by mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id AE8891803A8E; Sat, 16 May 2026 04:25:11 +0000 (UTC) From: Waiman Long To: Chen Ridong , Tejun Heo , Johannes Weiner , =?UTF-8?q?Michal=20Koutn=C3=BD?= , Ingo Molnar , Peter Zijlstra , Juri Lelli , Vincent Guittot , Dietmar Eggemann , Steven Rostedt , Ben Segall , Mel Gorman , Valentin Schneider , K Prateek Nayak Cc: cgroups@vger.kernel.org, linux-kernel@vger.kernel.org, Aaron Tomlin , Waiman Long Subject: [PATCH cgroup/for-next v2 1/5] cgroup/cpuset: Add a cpuset_reserve_dl_bw() helper Date: Sat, 16 May 2026 00:24:44 -0400 Message-ID: <20260516042448.698216-2-longman@redhat.com> In-Reply-To: <20260516042448.698216-1-longman@redhat.com> References: <20260516042448.698216-1-longman@redhat.com> Precedence: bulk X-Mailing-List: cgroups@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 3.4.1 on 10.30.177.111 Extract the DL bandwidth allocation code in cpuset_attach() to a new cpuset_reserve_dl_bw() helper to simplify code. No functional change is expected. Signed-off-by: Waiman Long --- kernel/cgroup/cpuset.c | 53 ++++++++++++++++++++++++------------------ 1 file changed, 30 insertions(+), 23 deletions(-) diff --git a/kernel/cgroup/cpuset.c b/kernel/cgroup/cpuset.c index bcefc9f50ac5..7cae47829013 100644 --- a/kernel/cgroup/cpuset.c +++ b/kernel/cgroup/cpuset.c @@ -2980,6 +2980,25 @@ static int cpuset_can_attach_check(struct cpuset *cs) return 0; } +static int cpuset_reserve_dl_bw(struct cpuset *cs) +{ + int cpu, ret; + + if (!cs->sum_migrate_dl_bw) + return 0; + + cpu = cpumask_any_and(cpu_active_mask, cs->effective_cpus); + if (unlikely(cpu >= nr_cpu_ids)) + return -EINVAL; + + ret = dl_bw_alloc(cpu, cs->sum_migrate_dl_bw); + if (ret) + return ret; + + cs->dl_bw_cpu = cpu; + return 0; +} + static void reset_migrate_dl_data(struct cpuset *cs) { cs->nr_migrate_dl_tasks = 0; @@ -2994,7 +3013,7 @@ static int cpuset_can_attach(struct cgroup_taskset *tset) struct cpuset *cs, *oldcs; struct task_struct *task; bool setsched_check; - int cpu, ret; + int ret; /* used later by cpuset_attach() */ cpuset_attach_old_cs = task_cs(cgroup_taskset_first(tset, &css)); @@ -3050,31 +3069,19 @@ static int cpuset_can_attach(struct cgroup_taskset *tset) } } - if (!cs->sum_migrate_dl_bw) - goto out_success; - - cpu = cpumask_any_and(cpu_active_mask, cs->effective_cpus); - if (unlikely(cpu >= nr_cpu_ids)) { - ret = -EINVAL; - goto out_unlock; - } - - ret = dl_bw_alloc(cpu, cs->sum_migrate_dl_bw); - if (ret) - goto out_unlock; - - cs->dl_bw_cpu = cpu; - -out_success: - /* - * Mark attach is in progress. This makes validate_change() fail - * changes which zero cpus/mems_allowed. - */ - cs->attach_in_progress++; + ret = cpuset_reserve_dl_bw(cs); out_unlock: - if (ret) + if (ret) { reset_migrate_dl_data(cs); + } else { + /* + * Mark attach is in progress. This makes validate_change() fail + * changes which zero cpus/mems_allowed. + */ + cs->attach_in_progress++; + } + mutex_unlock(&cpuset_mutex); return ret; } -- 2.54.0