centos man page for flush_scheduled_work

FLUSH_SCHEDULED_WORK(9) 					   Driver Basics					   FLUSH_SCHEDULED_WORK(9)

NAME
       flush_scheduled_work - ensure that any scheduled work has run to completion.

SYNOPSIS
       void flush_scheduled_work(void);

ARGUMENTS
       void
	   no arguments

DESCRIPTION
       Forces execution of the kernel-global workqueue and blocks until its completion.

       Think twice before calling this function! It's very easy to get into trouble if you don't take great care. Either of the following
       situations

WILL LEAD TO DEADLOCK
       One of the work items currently on the workqueue needs to acquire a lock held by your code or its caller.

       Your code is running in the context of a work routine.

       They will be detected by lockdep when they occur, but the first might not occur very often. It depends on what work items are on the
       workqueue and what locks they need, which you have no control over.

       In most situations flushing the entire workqueue is overkill; you merely need to know that a particular work item isn't queued and isn't
       running. In such cases you should use cancel_delayed_work_sync or cancel_work_sync instead.

COPYRIGHT
Kernel Hackers Manual 3.10					     June 2014						   FLUSH_SCHEDULED_WORK(9)