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Subject: Re: [PATCH] BUG(): sched.c: Line 944
From: Robert Love <rml@tech9.net>
To: Linus Torvalds <torvalds@transmeta.com>
Cc: linux-kernel@vger.kernel.org
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	<1032250378.969.112.camel@phantasy>
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Date: 17 Sep 2002 04:59:51 -0400
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On Tue, 2002-09-17 at 04:12, Robert Love wrote:

> I implemented exactly what you detailed, with one change: we need to
> check kernel_locked() before setting lock_depth because it is valid to
> exit() while holding the BKL.  Aside from kernel code that does it
> intentionally, crashed code (e.g. modules) would have the same problem.

fsck, this is non-ending... obviously, this is insufficient:
preempt_count will equal two if the BKL was previously held and
in_atomic() will trip.

This should work:

	if (likely(!kernel_locked())
		tsk->lock_depth = -2;
	else {
		/* compensate for BKL; we still cannot preempt */
		preempt_enable_no_resched();
	}

look sane?

Now, remind me why this is all worth it...

	Robert Love

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