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Fri, 13 Mar 2026 12:01:07 -0400 X-MC-Unique: ekej8OXZOzilGQcM9jf5Cg-1 X-Mimecast-MFC-AGG-ID: ekej8OXZOzilGQcM9jf5Cg_1773417665 Received: from mx-prod-int-06.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-06.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.93]) (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 374A218002DD; Fri, 13 Mar 2026 16:01:05 +0000 (UTC) Received: from [10.22.65.113] (unknown [10.22.65.113]) by mx-prod-int-06.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id B4B7B180075D; Fri, 13 Mar 2026 16:01:02 +0000 (UTC) Message-ID: <62813cce-36b7-4255-b748-dc450d83aa3c@redhat.com> Date: Fri, 13 Mar 2026 12:01:01 -0400 Precedence: bulk X-Mailing-List: cgroups@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH] cgroup/cpuset: Replace use of system_unbound_wq with system_dfl_wq To: Marco Crivellari , linux-kernel@vger.kernel.org, cgroups@vger.kernel.org Cc: Tejun Heo , Lai Jiangshan , Frederic Weisbecker , Sebastian Andrzej Siewior , Michal Hocko , Chen Ridong , Johannes Weiner , Michal Koutny References: <20260313154520.302888-1-marco.crivellari@suse.com> Content-Language: en-US From: Waiman Long In-Reply-To: <20260313154520.302888-1-marco.crivellari@suse.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 3.4.1 on 10.30.177.93 On 3/13/26 11:45 AM, Marco Crivellari wrote: > This patch continues the effort to refactor workqueue APIs, which has begun > with the changes introducing new workqueues and a new alloc_workqueue flag: > > commit 128ea9f6ccfb ("workqueue: Add system_percpu_wq and system_dfl_wq") > commit 930c2ea566af ("workqueue: Add new WQ_PERCPU flag") > > The point of the refactoring is to eventually alter the default behavior of > workqueues to become unbound by default so that their workload placement is > optimized by the scheduler. > > Before that to happen, workqueue users must be converted to the better named > new workqueues with no intended behaviour changes: > > system_wq -> system_percpu_wq > system_unbound_wq -> system_dfl_wq > > This way the old obsolete workqueues (system_wq, system_unbound_wq) can be > removed in the future. > > Link: https://lore.kernel.org/all/20250221112003.1dSuoGyc@linutronix.de/ > Suggested-by: Tejun Heo > Signed-off-by: Marco Crivellari > --- > kernel/cgroup/cpuset.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/kernel/cgroup/cpuset.c b/kernel/cgroup/cpuset.c > index e200de7c60b6..b399f5d0a158 100644 > --- a/kernel/cgroup/cpuset.c > +++ b/kernel/cgroup/cpuset.c > @@ -3937,7 +3937,7 @@ static void cpuset_handle_hotplug(void) > * item at all, this is not a problem. > */ > if (update_housekeeping || force_sd_rebuild) > - queue_work(system_unbound_wq, &hk_sd_work); > + queue_work(system_dfl_wq, &hk_sd_work); > > free_tmpmasks(ptmp); > } Thanks for the patch, but there is another patch that makes the same change as part of a larger fix to the cpuset code. See commit ca174c705db5 ("cgroup/cpuset: Call rebuild_sched_domains() directly in hotplug")  in the cgroup tree. Thanks, Longman