Date: Wed, 12 Jun 2013 11:36:52 -0700 From: Alfred Perlstein <bright@mu.org> To: Luigi Rizzo <rizzo@iet.unipi.it> Cc: current@freebsd.org Subject: Re: copyin()/copyout() constraints ? Message-ID: <51B8BFC4.303@mu.org> In-Reply-To: <20130612180115.GA27892@onelab2.iet.unipi.it> 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 > _______________________________________________ > freebsd-current@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-current > To unsubscribe, send any mail to "freebsd-current-unsubscribe@freebsd.org" > -- Alfred Perlstein VP Software Engineering, iXsystems
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