From 87c21e240659c859c7db538df6b1eee9db423013 Mon Sep 17 00:00:00 2001 From: Marco Crivellari Date: Thu, 30 Oct 2025 16:47:37 +0100 Subject: [PATCH] ACPI: EC: 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/20251030154739.262582-4-marco.crivellari@suse.com Signed-off-by: Rafael J. Wysocki --- drivers/acpi/ec.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/acpi/ec.c b/drivers/acpi/ec.c index 7855bbf752b1e..59b3d50ff01ec 100644 --- a/drivers/acpi/ec.c +++ b/drivers/acpi/ec.c @@ -2294,7 +2294,8 @@ static int acpi_ec_init_workqueues(void) ec_wq = alloc_ordered_workqueue("kec", 0); if (!ec_query_wq) - ec_query_wq = alloc_workqueue("kec_query", 0, ec_max_queries); + ec_query_wq = alloc_workqueue("kec_query", WQ_PERCPU, + ec_max_queries); if (!ec_wq || !ec_query_wq) { acpi_ec_destroy_workqueues(); -- 2.47.3