workqueue: Implement workqueue_set_min_active()

Since 5797b1c189 ("workqueue: Implement system-wide nr_active enforcement
for unbound workqueues"), unbound workqueues have separate min_active which
sets the number of interdependent work items that can be handled. This value
is currently initialized to WQ_DFL_MIN_ACTIVE which is 8. This isn't high
enough for some users, let's add an interface to adjust the setting.

Signed-off-by: Tejun Heo <tj@kernel.org>
This commit is contained in:
Tejun Heo 2024-02-08 14:11:56 -10:00
parent 516d3dc99f
commit 8f172181f2
2 changed files with 29 additions and 0 deletions

View File

@ -553,6 +553,8 @@ extern bool flush_rcu_work(struct rcu_work *rwork);
extern void workqueue_set_max_active(struct workqueue_struct *wq,
int max_active);
extern void workqueue_set_min_active(struct workqueue_struct *wq,
int min_active);
extern struct work_struct *current_work(void);
extern bool current_is_workqueue_rescuer(void);
extern bool workqueue_congested(int cpu, struct workqueue_struct *wq);

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@ -5629,6 +5629,33 @@ void workqueue_set_max_active(struct workqueue_struct *wq, int max_active)
}
EXPORT_SYMBOL_GPL(workqueue_set_max_active);
/**
* workqueue_set_min_active - adjust min_active of an unbound workqueue
* @wq: target unbound workqueue
* @min_active: new min_active value
*
* Set min_active of an unbound workqueue. Unlike other types of workqueues, an
* unbound workqueue is not guaranteed to be able to process max_active
* interdependent work items. Instead, an unbound workqueue is guaranteed to be
* able to process min_active number of interdependent work items which is
* %WQ_DFL_MIN_ACTIVE by default.
*
* Use this function to adjust the min_active value between 0 and the current
* max_active.
*/
void workqueue_set_min_active(struct workqueue_struct *wq, int min_active)
{
/* min_active is only meaningful for non-ordered unbound workqueues */
if (WARN_ON((wq->flags & (WQ_BH | WQ_UNBOUND | __WQ_ORDERED)) !=
WQ_UNBOUND))
return;
mutex_lock(&wq->mutex);
wq->saved_min_active = clamp(min_active, 0, wq->saved_max_active);
wq_adjust_max_active(wq);
mutex_unlock(&wq->mutex);
}
/**
* current_work - retrieve %current task's work struct
*