Messages in this thread | | | Date | Wed, 17 Dec 2008 01:21:29 +0300 | From | "Alexey Zaytsev" <> | Subject | Re: linux-next: Tree for December 11 |
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On Wed, Dec 17, 2008 at 00:08, Ingo Molnar <mingo@elte.hu> wrote:
>> >> The warning can also be reproduced in qemu, so it was easy to bisect. >> >> commit 7317d7b87edb41a9135e30be1ec3f7ef817c53dd >> Author: Nick Piggin <nickpiggin@yahoo.com.au> >> Date: Tue Sep 30 20:50:27 2008 +1000 >> >> sched: improve preempt debugging >> >> This patch helped me out with a problem I recently had.... >> >> Basically, when the kernel lock is held, then preempt_count >> underflow does not >> get detected until it is released which may be a long time (and arbitrarily, >> eg at different points it may be rescheduled). If the bkl is released at >> schedule, the resulting output is actually fairly cryptic... >> >> With any other lock that elevates preempt_count, it is illegal to schedule >> under it (which would get found pretty quickly). bkl allows scheduling with >> preempt_count elevated, which makes underflows hard to debug. >> >> Signed-off-by: Ingo Molnar <mingo@elte.hu> >> >> I understand that not this particular commit is buggy, but at least >> I've got someone to add to the CC. ;) >> >> Also the author's e-mail looks suspicious. > > Suspicious in what way?
Does not appear in signed-off-by.
> > Ingo >
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