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Date: Fri, 4 Oct 2002 07:11:06 -0600
From: "Brian F. G. Bidulock" <bidulock@openss7.org>
To: Andi Kleen <ak@suse.de>
Cc: linux-kernel@vger.kernel.org
Subject: Re: export of sys_call_table
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Andi,

On Fri, 04 Oct 2002, Andi Kleen wrote:

> "Brian F. G. Bidulock" <bidulock@openss7.org> writes:
> 
> 
> > 					   void *dataptr, int band, int flags)
> > 	{
> > 		int ret =3D -ENOSYS;
> > 		read_lock(&streams_call_lock);
> 
> I don't think you really want to use any spinlocks this way. They would
> make sleeping impossible and you could never legally do a copy_from/to_user
> in your system call. And how else would you access dataptr ? 
> 
> More likely you want an atomic_inc(&modulecounter) or perhaps a rw
> semaphore.

read_lock and write_lock are a rw semaphores, aren't they?

--brian

-- 
Brian F. G. Bidulock    ? The reasonable man adapts himself to the ?
bidulock@openss7.org    ? world; the unreasonable one persists in  ?
http://www.openss7.org/ ? trying  to adapt the  world  to himself. ?
                        ? Therefore  all  progress  depends on the ?
                        ? unreasonable man. -- George Bernard Shaw ?
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