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From: John Baldwin <jhb@FreeBSD.org>
To: des@des.no (Dag-Erling =?iso-8859-1?q?Sm=F8rgrav?=)
Date: Fri, 16 Jan 2004 15:23:32 -0500
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	<200401161458.34197.jhb@FreeBSD.org> <xzpvfnbslix.fsf@dwp.des.no>
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cc: "Robin P. Blanchard" <robin.blanchard@gactr.uga.edu>
cc: current@freebsd.org
Subject: Re: Panic with this morning's (~9am EDT, 15 jan 2004) sources.
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On Friday 16 January 2004 03:09 pm, Dag-Erling Sm=F8rgrav wrote:
> John Baldwin <jhb@FreeBSD.org> writes:
> >          You probably don't need to lock the new filedesc structure
> > while you are creating it until you've actually hooked it up to a
> > proc structure.
>
> Yes, I do.  fdgrowtable() for instance asserts that the filedesc is
> locked.

Then do this:

	while (newfdp blah fdp) {
		FILEDESC_UNLOCK(fdp);
		FILEDESC_LOCK(newfdp);
		fd_growtable(newfdp);
		FILEDESC_UNLOCK(newfdp);
		FILEDESC_LOCK(fdp);
	}

Since no other CPU or thread can possibly go near newfdp until it is hooked=
=20
into a process, you don't need to worry about locking it other than to=20
satisfy assertions while you are constructing it.

=2D-=20
John Baldwin <jhb@FreeBSD.org>  <><  http://www.FreeBSD.org/~jhb/
"Power Users Use the Power to Serve"  =3D  http://www.FreeBSD.org