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* [PATCH] thunderbolt: replace use of system_wq with system_percpu_wq
@ 2025-11-05 16:27 Marco Crivellari
  2025-11-07  9:44 ` Mika Westerberg
  0 siblings, 1 reply; 3+ messages in thread
From: Marco Crivellari @ 2025-11-05 16:27 UTC (permalink / raw)
  To: linux-kernel, linux-usb
  Cc: Tejun Heo, Lai Jiangshan, Frederic Weisbecker,
	Sebastian Andrzej Siewior, Marco Crivellari, Michal Hocko,
	Andreas Noever, Mika Westerberg, Yehezkel Bernat

Currently if a user enqueues 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 consistency cannot be addressed without refactoring the API.

This patch continues the effort to refactor worqueue APIs, which has begun
with the change introducing new workqueues and a new alloc_workqueue flag:

commit 128ea9f6ccfb ("workqueue: Add system_percpu_wq and system_dfl_wq")
commit 930c2ea566af ("workqueue: Add new WQ_PERCPU flag")

Replace system_wq with system_percpu_wq, keeping the old behavior.
The old wq (system_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>
---
 drivers/thunderbolt/tb.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/thunderbolt/tb.c b/drivers/thunderbolt/tb.c
index 4a94cb406bdf..7a3f76a852de 100644
--- a/drivers/thunderbolt/tb.c
+++ b/drivers/thunderbolt/tb.c
@@ -2636,7 +2636,7 @@ static int tb_alloc_dp_bandwidth(struct tb_tunnel *tunnel, int *requested_up,
 				 * the 10s already expired and we should
 				 * give the reserved back to others).
 				 */
-				mod_delayed_work(system_wq, &group->release_work,
+				mod_delayed_work(system_percpu_wq, &group->release_work,
 					msecs_to_jiffies(TB_RELEASE_BW_TIMEOUT));
 			}
 		}
-- 
2.51.1


^ permalink raw reply related	[flat|nested] 3+ messages in thread

* Re: [PATCH] thunderbolt: replace use of system_wq with system_percpu_wq
  2025-11-05 16:27 [PATCH] thunderbolt: replace use of system_wq with system_percpu_wq Marco Crivellari
@ 2025-11-07  9:44 ` Mika Westerberg
  2025-11-07 10:49   ` Marco Crivellari
  0 siblings, 1 reply; 3+ messages in thread
From: Mika Westerberg @ 2025-11-07  9:44 UTC (permalink / raw)
  To: Marco Crivellari
  Cc: linux-kernel, linux-usb, Tejun Heo, Lai Jiangshan,
	Frederic Weisbecker, Sebastian Andrzej Siewior, Michal Hocko,
	Andreas Noever, Mika Westerberg, Yehezkel Bernat

On Wed, Nov 05, 2025 at 05:27:36PM +0100, Marco Crivellari wrote:
> Currently if a user enqueues 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 consistency cannot be addressed without refactoring the API.
> 
> This patch continues the effort to refactor worqueue APIs, which has begun
> with the change introducing new workqueues and a new alloc_workqueue flag:
> 
> commit 128ea9f6ccfb ("workqueue: Add system_percpu_wq and system_dfl_wq")
> commit 930c2ea566af ("workqueue: Add new WQ_PERCPU flag")
> 
> Replace system_wq with system_percpu_wq, keeping the old behavior.
> The old wq (system_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>

Applied to thunderbolt.git/next, thanks!

^ permalink raw reply	[flat|nested] 3+ messages in thread

* Re: [PATCH] thunderbolt: replace use of system_wq with system_percpu_wq
  2025-11-07  9:44 ` Mika Westerberg
@ 2025-11-07 10:49   ` Marco Crivellari
  0 siblings, 0 replies; 3+ messages in thread
From: Marco Crivellari @ 2025-11-07 10:49 UTC (permalink / raw)
  To: Mika Westerberg
  Cc: linux-kernel, linux-usb, Tejun Heo, Lai Jiangshan,
	Frederic Weisbecker, Sebastian Andrzej Siewior, Michal Hocko,
	Andreas Noever, Mika Westerberg, Yehezkel Bernat

On Fri, Nov 7, 2025 at 10:44 AM Mika Westerberg
<mika.westerberg@linux.intel.com> wrote:
>[...]
> > Suggested-by: Tejun Heo <tj@kernel.org>
> > Signed-off-by: Marco Crivellari <marco.crivellari@suse.com>
>
> Applied to thunderbolt.git/next, thanks!

Many thanks!


-- 

Marco Crivellari

L3 Support Engineer, Technology & Product

^ permalink raw reply	[flat|nested] 3+ messages in thread

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Thread overview: 3+ messages (download: mbox.gz follow: Atom feed
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2025-11-05 16:27 [PATCH] thunderbolt: replace use of system_wq with system_percpu_wq Marco Crivellari
2025-11-07  9:44 ` Mika Westerberg
2025-11-07 10:49   ` Marco Crivellari

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