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From: Oliver Neukum <oliver@neukum.name>
To: pmenage@ensim.com (pmenage@ensim.com)
Subject: Re: BKL removal
Date: Mon, 8 Jul 2002 23:45:03 +0200
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Am Montag, 8. Juli 2002 21:00 schrieb pmenage@ensim.com:
> In article <0C01A29FBAE24448A792F5C68F5EA47D2B0C8A@nasdaq.ms.ensim.com>,
>
> you write:
> >The BKL, unless used unbalanced, can never cause a bug.
> >It could be insufficient or superfluous, but never be really buggy in
> >itself.
>
> Unless you're including incorrect nesting in your definition of
> "unbalanced", that's not really true. E.g. lock_kernel() anywhere that
> dcache_lock is held can deadlock against anywhere that does a path
> lookup with the BKL held (such as do_coredump()).

Yes, for the record. If you mix locking orders you can deadlock, as with any
other lock. And the BKL needs process context. And it doesn't help
against races with interrupts.

	Regards
		Oliver

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