centos man page for drain_workqueue

DRAIN_WORKQUEUE(9)						   Driver Basics						DRAIN_WORKQUEUE(9)

NAME
       drain_workqueue - drain a workqueue

SYNOPSIS
       void drain_workqueue(struct workqueue_struct * wq);

ARGUMENTS
       wq
	   workqueue to drain

DESCRIPTION
       Wait until the workqueue becomes empty. While draining is in progress, only chain queueing is allowed. IOW, only currently pending or
       running work items on wq can queue further work items on it.  wq is flushed repeatedly until it becomes empty. The number of flushing is
       detemined by the depth of chaining and should be relatively short. Whine if it takes too long.

COPYRIGHT
Kernel Hackers Manual 3.10					     June 2014							DRAIN_WORKQUEUE(9)