copyin()/copyout() constraints ?
bright at mu.org
Wed Jun 12 18:37:05 UTC 2013
On 6/12/13 11:01 AM, Luigi Rizzo wrote:
> 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.
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VP Software Engineering, iXsystems
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