Commit 7eb28030 authored by Marco Crivellari's avatar Marco Crivellari Committed by Thomas Gleixner
Browse files

smp: Use system_percpu_wq instead of system_wq 



When a caller enqueues a work item using schedule_delayed_work() the used
wq is "system_wq" (per-cpu wq) while queue_delayed_work() uses
WORK_CPU_UNBOUND (used when no target CPU is specified). The same applies
to schedule_work() that is using system_wq and queue_work(), which again
makes use of WORK_CPU_UNBOUND.

This lack of consistency cannot be addressed without refactoring the API.

Continue the effort to refactor workqueue APIs, which began with the
introduction of new workqueues and a new alloc_workqueue() flag in:

  commit 128ea9f6 ("workqueue: Add system_percpu_wq and system_dfl_wq")
  commit 930c2ea5 ("workqueue: Add new WQ_PERCPU flag")

and switch smp_call_on_cpu() to use system_percpu_wq because system_wq is
going away once the ongoing workqueue restructuring is done.

Suggested-by: default avatarTejun Heo <tj@kernel.org>
Signed-off-by: default avatarMarco Crivellari <marco.crivellari@suse.com>
Signed-off-by: default avatarThomas Gleixner <tglx@kernel.org>
Reviewed-by: default avatarFrederic Weisbecker <frederic@kernel.org>
Link: https://patch.msgid.link/20251110170332.319314-1-marco.crivellari@suse.com
parent b0473dcd

kernel/smp.c

+1 −1
Original line number Diff line number Diff line
@@ -1185,7 +1185,7 @@ int smp_call_on_cpu(unsigned int cpu, int (*func)(void *), void *par, bool phys) 
	if (cpu >= nr_cpu_ids || !cpu_online(cpu))

		return -ENXIO;



	queue_work_on(cpu, system_wq, &sscs.work);

	queue_work_on(cpu, system_percpu_wq, &sscs.work);

	wait_for_completion(&sscs.done);

	destroy_work_on_stack(&sscs.work);