>Number: 165382
>Category: misc
>Synopsis: [kern] taskqueue_unblock doesn't unblock currently queued tasks
>Confidential: no
>Severity: non-critical
>Priority: low
>Responsible: freebsd-bugs
>State: open
>Quarter:
>Keywords:
>Date-Required:
>Class: sw-bug
>Submitter-Id: current-users
>Arrival-Date: Wed Feb 22 02:00:24 UTC 2012
>Closed-Date:
>Last-Modified:
>Originator: Adrian Chadd
>Release: 9.0-RELEASE
>Organization:
>Environment:
>Description:
This is more a note than a bug.

taskqueue_block() only marks newly queued items as PENDING. If a task is queued
to the taskqueue to be run, taskqueue_block() doesn't stop that from occuring.

For example, take a single-thread taskqueue:

* task A is queued - wakeup_one() is called
* task B is queued - wakeup_one() is called
* task A starts to run
* taskqueue_block() is called from another thread
* task C is queued - but instead is marked as PENDING
* task A completes
* task B completes
* task C waits for taskqueue_unblock() to occur.

This means that code which calls taskqueue_block() can't assume that once
currently running tasks are completed, nothing further will be done. It can
only assume that once currently QUEUED tasks are completed, nothing further
will be queued.

These two are subtly different.
>How-To-Repeat:
N/A
>Fix:
N/A

>Release-Note:
>Audit-Trail:
>Unformatted:
_______________________________________________
freebsd-bugs@xxxxxxxxxxx mailing list
http://lists.freebsd.org/mailman/listinfo/freebsd-bugs
To unsubscribe, send any mail to "freebsd-bugs-unsubscribe@xxxxxxxxxxx"