tjh.dev / kernel
Linux kernel mirror (for testing) git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel os linux
1
fork

Configure Feed

Select the types of activity you want to include in your feed.

workqueue: 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: Tejun Heo <tj@kernel.org>

authored by

Marco Crivellari and committed by
Tejun Heo f6cfa602 ad7c7f4b

+3 -3
+2 -2
include/linux/workqueue.h
··· 783 783 _wq == system_highpri_wq) || \ 784 784 (__builtin_constant_p(_wq == system_long_wq) && \ 785 785 _wq == system_long_wq) || \ 786 - (__builtin_constant_p(_wq == system_unbound_wq) && \ 787 - _wq == system_unbound_wq) || \ 786 + (__builtin_constant_p(_wq == system_dfl_wq) && \ 787 + _wq == system_dfl_wq) || \ 788 788 (__builtin_constant_p(_wq == system_freezable_wq) && \ 789 789 _wq == system_freezable_wq) || \ 790 790 (__builtin_constant_p(_wq == system_power_efficient_wq) && \
+1 -1
kernel/workqueue.c
··· 2932 2932 raw_spin_unlock_irq(&pool->lock); 2933 2933 2934 2934 if (do_cull) 2935 - queue_work(system_unbound_wq, &pool->idle_cull_work); 2935 + queue_work(system_dfl_wq, &pool->idle_cull_work); 2936 2936 } 2937 2937 2938 2938 /**