Messages in this thread | | | Subject | Re: [git pull] scheduler fixes | From | Peter Zijlstra <> | Date | Sat, 31 Jan 2009 18:23:52 +0100 |
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On Sat, 2009-01-31 at 18:11 +0100, Peter Zijlstra wrote: > > diff --git a/kernel/sched.c b/kernel/sched.c > > index 52bbf1c..5686bb5 100644 > > --- a/kernel/sched.c > > +++ b/kernel/sched.c > > @@ -4440,7 +4450,7 @@ void __kprobes sub_preempt_count(int val) > > /* > > * Underflow? > > */ > > - if (DEBUG_LOCKS_WARN_ON(val > preempt_count())) > > + if (DEBUG_LOCKS_WARN_ON(val > preempt_count() - (!!kernel_locked()))) > > return; > > /* > > * Is the spinlock portion underflowing?
Since the commit msg of 01e3eb8 says:
kernel_locked() is not a valid test in IRQ context (we update the BKL's ->lock_depth and the preempt count separately and non-atomicalyy), so we cannot put it into the generic preempt debugging checks which can run in IRQ contexts too.
Another possibility would be writing it like:
if (DEBUG_LOCKS_WARN_ON(val > preempt_count() - (in_interrupt() ? 0 : !!kernel_locked())))
Which might just work because we're in sub_preempt_count, before we actually do the subtraction, so in_interrupt() will still be true.
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