svn commit: r308424 - head/sys/arm/broadcom/bcm2835

[Hans Petter Selasky]

Hi,

On 11/09/16 16:02, John Baldwin wrote:
 > On the other hand, doing the wakeup outside of the lock
> avoids preempting during the wakeup only to immediately block on the lock and
> switch back to the thread that did the wakeup.

This can be predicted and avoided by the turnstiles iff cv_signal() is 
used under a lock. Else not.

Won't doing the wakeup outside the lock cause double preemtion? First at 
mtx_unlock() and then inside cv_signal()/cv_broadcast().

--HPS