K 10
svn:author
V 8
lstewart
K 8
svn:date
V 27
2008-11-20T04:04:22.457032Z
K 7
svn:log
V 806
Fix a bug in kthread_exit() which led to potential deadlock in code that
was relying on the documented behaviour in the kthread(9) man page. This brings
the wakeup() related behaviour of kthread_exit in 7.x inline with 8.x.

I've tested the fix with a simple scenario that was previously deadlocking. A
waiting thread waits on a terminating thread by calling mtx_sleep() with the
"chan" argument set to the *thread obtained by calling
FIRST_THREAD_IN_PROC(*proc_that_will_exit).

Without this patch, the waiting thread never gets woken because kthread_exit()
calls wakeup() on the *proc. With this patch, the wait thread gets woken and
all is good in the world again.

For more details, refer to:
http://lists.freebsd.org/pipermail/freebsd-arch/2008-November/008688.html

Discussed with:	attilio@, julian@

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