On Sun, 17 Feb 2002, Matthew Dillon wrote:

>     Ok, I've looked at the code more carefully and I understand how this
>     works now.  However, it is not enough in an SMP environment.  You
>     need a generation count in the timecounter structure and you also need
>     a synchronization point when you switch time counters or a process
>     running on a different cpu may wind up using a time counter that is being
>     actively updated.

Er, the comment in patch says it needs a generation count.  Unfortunately,
we only have half a synchronization point now -- there is a sched_lock()
in the update code but nothing in the code that reads the pointer.
Maybe a large value of NTIMECOUNTER would help after all.  We can afford
to o miss a few timecounter changes if we have a lot of timecounter


To Unsubscribe: send mail to [EMAIL PROTECTED]
with "unsubscribe freebsd-current" in the body of the message

Reply via email to