From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) (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 0EB023B47D7 for ; Fri, 29 May 2026 21:28:52 +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=1780090134; cv=none; b=sNnV6YEueAtLLes3n/KNZIuzjHMdmeUShd3LmkFxePrg11tuD7E9oMmf+7GQE1Zfft6a/u0TSqKsf4Jtgoply8KwqnWQepnDQT4KK0yC0cts80L5BB+aQHaO1/qfxVAJmPvNfj2gD7lXWJrqjec2QI/zfXkB8c4BKS6Susxhp8Y= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780090134; c=relaxed/simple; bh=dauKbPjpI0fNqAAsQtAR1VwjFqQ0hhG0aIcjoX2j3b8=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=s6HCOsqquyvXKQ5CILq+QipHVi3TmfvlWkUcIDw37t7EwgWo+bcun6mBPo9B1R3G1rFlCPr3QxT4c2Uv04FqG7EK0tT9deB4CeqrqQILqc7UEBgv9VysnDhmUJX0VNv/c/ZK/tt2Fp14jEPoSxLCx7A03b/5djRFJU1KU2uCOIs= 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=fgyJ4OTL; 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="fgyJ4OTL" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1780090132; 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=pGtNVc/HlFeIKiY6aBuwFV5+Ml3YH/UwqpIoqUttfKI=; b=fgyJ4OTLrZvviL4gycnYXqyR1tKffh/wtyP82bCEFyZKmICgSQ3pyT3yLfj3WoKkfP3Rpy 6R4w3nbP5Lx76+UeLG/ZXadAcrKoK84OKYouK+OTvxC8u6v6ouGiLyP3bJ7e4Tkc5S4VGG 9SWzH8sW4wV0ASNOlQ7Yr11QS04to5E= Received: from mx-prod-mc-03.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-347-NrVAW1A9OU6lM4osxMxLKQ-1; Fri, 29 May 2026 17:28:50 -0400 X-MC-Unique: NrVAW1A9OU6lM4osxMxLKQ-1 X-Mimecast-MFC-AGG-ID: NrVAW1A9OU6lM4osxMxLKQ_1780090129 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-03.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id E304619560BB; Fri, 29 May 2026 21:28:48 +0000 (UTC) Received: from llong-thinkpadp16vgen1.westford.csb (unknown [10.22.64.54]) by mx-prod-int-03.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id C448F19560A3; Fri, 29 May 2026 21:28:46 +0000 (UTC) From: Waiman Long To: Chen Ridong , Tejun Heo , Johannes Weiner , =?UTF-8?q?Michal=20Koutn=C3=BD?= , Peter Zijlstra Cc: cgroups@vger.kernel.org, linux-kernel@vger.kernel.org, Aaron Tomlin , Guopeng Zhang , Waiman Long Subject: [PATCH-next v4 2/6] cgroup/cpuset: Add a cpuset_reserve_dl_bw() helper Date: Fri, 29 May 2026 17:21:04 -0400 Message-ID: <20260529212108.120506-3-longman@redhat.com> In-Reply-To: <20260529212108.120506-1-longman@redhat.com> References: <20260529212108.120506-1-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 3.0 on 10.30.177.12 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 961427cd83a5..a6f191b48529 100644 --- a/kernel/cgroup/cpuset.c +++ b/kernel/cgroup/cpuset.c @@ -2992,6 +2992,25 @@ 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; @@ -3006,7 +3025,7 @@ 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)); @@ -3062,31 +3081,19 @@ 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