diff mbox series

[v6,08/21] workqueue: Use global variant for add_timer()

Message ID 20230510072817.116056-9-anna-maria@linutronix.de
State New
Headers
Series timer: Move from a push remote at enqueue to a pull at expiry model |

Commit Message

Anna-Maria Behnsen May 10, 2023, 7:28 a.m. UTC 
  The implementation of the NOHZ pull at expiry model will change the timer
bases per CPU. Timers, that have to expire on a specific CPU, require the
TIMER_PINNED flag. If the CPU doesn't matter, the TIMER_PINNED flag must be
dropped. This is required for call sites which use the timer alternately as
pinned and not pinned timer like workqueues do.

Therefore use add_timer_global() to make sure TIMER_PINNED flag is dropped.

Signed-off-by: Anna-Maria Behnsen <anna-maria@linutronix.de>
Cc: Tejun Heo <tj@kernel.org>
Cc: Lai Jiangshan <jiangshanlai@gmail.com>
---
v6:
  - New patch: As v6 provides unconditially setting TIMER_PINNED flag in
    add_timer_on() workqueue requires new add_timer_global() variant.
---
 kernel/workqueue.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Comments

Tejun Heo May 10, 2023, 7:30 p.m. UTC | #1 
On Wed, May 10, 2023 at 09:28:04AM +0200, Anna-Maria Behnsen wrote:
> The implementation of the NOHZ pull at expiry model will change the timer
> bases per CPU. Timers, that have to expire on a specific CPU, require the
> TIMER_PINNED flag. If the CPU doesn't matter, the TIMER_PINNED flag must be
> dropped. This is required for call sites which use the timer alternately as
> pinned and not pinned timer like workqueues do.
> 
> Therefore use add_timer_global() to make sure TIMER_PINNED flag is dropped.
> 
> Signed-off-by: Anna-Maria Behnsen <anna-maria@linutronix.de>
> Cc: Tejun Heo <tj@kernel.org>
> Cc: Lai Jiangshan <jiangshanlai@gmail.com>

Acked-by: Tejun Heo <tj@kernel.org>

Please feel free to route the patch as you see fit.

Thanks.
Frederic Weisbecker June 5, 2023, 10:16 p.m. UTC | #2 
Le Wed, May 10, 2023 at 09:28:04AM +0200, Anna-Maria Behnsen a écrit :
> The implementation of the NOHZ pull at expiry model will change the timer
> bases per CPU. Timers, that have to expire on a specific CPU, require the
> TIMER_PINNED flag. If the CPU doesn't matter, the TIMER_PINNED flag must be
> dropped. This is required for call sites which use the timer alternately as
> pinned and not pinned timer like workqueues do.
> 
> Therefore use add_timer_global() to make sure TIMER_PINNED flag is dropped.
> 
> Signed-off-by: Anna-Maria Behnsen <anna-maria@linutronix.de>
> Cc: Tejun Heo <tj@kernel.org>
> Cc: Lai Jiangshan <jiangshanlai@gmail.com>

Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
diff mbox series

Patch

diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index 4666a1a92a31..5c529f19e709 100644
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -1682,7 +1682,7 @@  static void __queue_delayed_work(int cpu, struct workqueue_struct *wq,
 	if (unlikely(cpu != WORK_CPU_UNBOUND))
 		add_timer_on(timer, cpu);
 	else
-		add_timer(timer);
+		add_timer_global(timer);
 }
 
 /**