copyin()/copyout() constraints ?

[Alfred Perlstein]

On 6/12/13 11:01 AM, Luigi Rizzo wrote:
> hi,
> is it possible to run copyin() or copyout() in one of these cases:
> 1. while holding a spinlock
> 2. while holding a regular mutex/lock
> 3. while holding a read lock (on an RWLOCK or RMLOCK)
> 4. while holding a write lock (on an RWLOCK or RMLOCK)
>
> I suspect #1 is forbidden, but am a bit unclear for the
> other cases.
No on all of the above unless the memory is wired.

You need a sx or semaphore.

-Alfred
>
> thanks
> luigi
> _______________________________________________
> freebsd-current at freebsd.org mailing list
> http://lists.freebsd.org/mailman/listinfo/freebsd-current
> To unsubscribe, send any mail to "freebsd-current-unsubscribe at freebsd.org"
>


-- 
Alfred Perlstein
VP Software Engineering, iXsystems