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From: Alfred Perlstein <bright@mu.org>
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To: Luigi Rizzo <rizzo@iet.unipi.it>
Subject: Re: copyin()/copyout() constraints ?
References: <20130612180115.GA27892@onelab2.iet.unipi.it>
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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
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-- 
Alfred Perlstein
VP Software Engineering, iXsystems