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Date: Wed, 5 Mar 1997 15:45:04 +1100
From: Bruce Evans <bde@zeta.org.au>
Message-Id: <199703050445.PAA07046@godzilla.zeta.org.au>
To: dg@root.com, freebsd-bugs@freefall.freebsd.org
Subject: Re: kern/2875: vinvalbuf() clobbers b_vnbufs chain
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> >>    Hmmm, the fix seems overly complicated. How about this instead:
> >
> >Your fix inhibit disk I/O interruption for more long time.  If this
> >is not a problem, I prefer your fix.
> 
>    I don't think it's a problem. The actual delay is fairly low in practice
> (probably less than 50us), and letting an interrupt through prior to the

50us is fairly large on a 386, and very large on a P5.  Lite2 locks only
the B_BUSY test and set here.  The whole loop is not locked in any case
because of the explicit sleep in the loop and the implicit sleep in
VOP_BWRITE().  Sort-of-locking of the whole loop together with the bug
was introduced without special comment in rev.1.59.

Bruce