diff options
| author | Marco Crivellari <marco.crivellari@suse.com> | 2025-10-30 16:47:37 +0100 |
|---|---|---|
| committer | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2025-11-03 18:45:42 +0100 |
| commit | 87c21e240659c859c7db538df6b1eee9db423013 (patch) | |
| tree | 61c8887bf00d57b3ca1a8ba3621729bf79f650aa | |
| parent | 6447ece47c7399894f36bbfda3dfce13d0330c76 (diff) | |
ACPI: EC: Add WQ_PERCPU to alloc_workqueue() users
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 <tj@kernel.org>
Signed-off-by: Marco Crivellari <marco.crivellari@suse.com>
[ rjw: Subject adjustment ]
Link: https://patch.msgid.link/20251030154739.262582-4-marco.crivellari@suse.com
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
| -rw-r--r-- | drivers/acpi/ec.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/drivers/acpi/ec.c b/drivers/acpi/ec.c index 7855bbf752b1..59b3d50ff01e 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(); |