Commit e6267616 authored by Tejun Heo's avatar Tejun Heo
Browse files

workqueue: implement current_is_workqueue_rescuer() 



Implement a function which queries whether it currently is running off
a workqueue rescuer.  This will be used to convert writeback to
workqueue.

Signed-off-by: default avatarTejun Heo <tj@kernel.org>
parent 226223ab

include/linux/workqueue.h

+1 −0
Original line number Diff line number Diff line
@@ -451,6 +451,7 @@ extern bool cancel_delayed_work_sync(struct delayed_work *dwork); 


extern void workqueue_set_max_active(struct workqueue_struct *wq,

				     int max_active);

extern bool current_is_workqueue_rescuer(void);

extern bool workqueue_congested(int cpu, struct workqueue_struct *wq);

extern unsigned int work_busy(struct work_struct *work);

kernel/workqueue.c

+13 −0
Original line number Diff line number Diff line
@@ -4071,6 +4071,19 @@ void workqueue_set_max_active(struct workqueue_struct *wq, int max_active) 
}

EXPORT_SYMBOL_GPL(workqueue_set_max_active);



/**

 * current_is_workqueue_rescuer - is %current workqueue rescuer?

 *

 * Determine whether %current is a workqueue rescuer.  Can be used from

 * work functions to determine whether it's being run off the rescuer task.

 */

bool current_is_workqueue_rescuer(void)

{

	struct worker *worker = current_wq_worker();



	return worker && worker == worker->current_pwq->wq->rescuer;

}



/**

 * workqueue_congested - test whether a workqueue is congested

 * @cpu: CPU in question