drivers/block: replace use of system_unbound_wq with system_dfl_wq

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@kernel.org>
Signed-off-by: Marco Crivellari <marco.crivellari@suse.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
Marco Crivellari 2025-09-05 10:51:40 +02:00 committed by Jens Axboe
parent 51723bf926
commit 456cefcb31
1 changed files with 1 additions and 1 deletions

View File

@ -1085,7 +1085,7 @@ static int read_from_bdev_sync(struct zram *zram, struct page *page,
work.entry = entry; work.entry = entry;
INIT_WORK_ONSTACK(&work.work, zram_sync_read); INIT_WORK_ONSTACK(&work.work, zram_sync_read);
queue_work(system_unbound_wq, &work.work); queue_work(system_dfl_wq, &work.work);
flush_work(&work.work); flush_work(&work.work);
destroy_work_on_stack(&work.work); destroy_work_on_stack(&work.work);