From ec4291f524a3218067e38dc51c1ea1d3deb8f5d9 Mon Sep 17 00:00:00 2001 From: Marco Crivellari Date: Thu, 30 Oct 2025 16:47:38 +0100 Subject: [PATCH] ACPI: OSL: Add WQ_PERCPU to alloc_workqueue() users MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit Currently if a user enqueue a work item using schedule_delayed_work() the used wq is "system_wq" (per-cpu wq) while queue_delayed_work() use WORK_CPU_UNBOUND (used when a cpu is not specified). The same applies to schedule_work() that is using system_wq and queue_work(), that makes use again of WORK_CPU_UNBOUND. This lack of consistentcy cannot be addressed without refactoring the API. alloc_workqueue() treats all queues as per-CPU by default, while unbound workqueues must opt-in via WQ_UNBOUND. This default is suboptimal: most workloads benefit from unbound queues, allowing the scheduler to place worker threads where they’re needed and reducing noise when CPUs are isolated. This change adds a new WQ_PERCPU flag to explicitly request alloc_workqueue() to be per-cpu when WQ_UNBOUND has not been specified. With the introduction of the WQ_PERCPU flag (equivalent to !WQ_UNBOUND), any alloc_workqueue() caller that doesn’t explicitly specify WQ_UNBOUND must now use WQ_PERCPU. Once migration is complete, WQ_UNBOUND can be removed and unbound will become the implicit default. Suggested-by: Tejun Heo Signed-off-by: Marco Crivellari [ rjw: Subject adjustment ] Link: https://patch.msgid.link/20251030154739.262582-5-marco.crivellari@suse.com Signed-off-by: Rafael J. Wysocki --- drivers/acpi/osl.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/acpi/osl.c b/drivers/acpi/osl.c index a79a5d47bdb80..05393a7315fec 100644 --- a/drivers/acpi/osl.c +++ b/drivers/acpi/osl.c @@ -1694,8 +1694,8 @@ acpi_status __init acpi_os_initialize(void) acpi_status __init acpi_os_initialize1(void) { - kacpid_wq = alloc_workqueue("kacpid", 0, 1); - kacpi_notify_wq = alloc_workqueue("kacpi_notify", 0, 0); + kacpid_wq = alloc_workqueue("kacpid", WQ_PERCPU, 1); + kacpi_notify_wq = alloc_workqueue("kacpi_notify", WQ_PERCPU, 0); kacpi_hotplug_wq = alloc_ordered_workqueue("kacpi_hotplug", 0); BUG_ON(!kacpid_wq); BUG_ON(!kacpi_notify_wq); -- 2.47.3