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.
system_unbound_wq should be the default workqueue so as not to enforce
locality constraints for random work whenever it's not required.
Adding system_dfl_wq to encourage its use when unbound work should be used.
queue_work() / queue_delayed_work() / mod_delayed_work() will now use the
new unbound wq: whether the user still use the old wq a warn will be
printed along with a wq redirect to the new one.
The old system_unbound_wq will be kept for a few release cycles.
Suggested-by: Tejun Heo <tj@xxxxxxxxxx>
Signed-off-by: Marco Crivellari <marco.crivellari@xxxxxxxx>
---
kernel/padata.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/kernel/padata.c b/kernel/padata.c
index b3d4eacc4f5d..76b39fc8b326 100644
--- a/kernel/padata.c
+++ b/kernel/padata.c
@@ -551,9 +551,9 @@ void __init padata_do_multithreaded(struct padata_mt_job *job)
do {
nid = next_node_in(old_node, node_states[N_CPU]);
} while (!atomic_try_cmpxchg(&last_used_nid, &old_node, nid));
- queue_work_node(nid, system_unbound_wq, &pw->pw_work);
+ queue_work_node(nid, system_dfl_wq, &pw->pw_work);
} else {
- queue_work(system_unbound_wq, &pw->pw_work);
+ queue_work(system_dfl_wq, &pw->pw_work);
}
/* Use the current thread, which saves starting a workqueue worker. */
--
2.51.0
