Messages in this thread | | | Date | Thu, 15 Apr 2010 19:39:55 +0200 | From | Ingo Molnar <> | Subject | Re: linux-next: PowerPC WARN_ON_ONCE() after merge of the final tree (tip related) |
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* Frederic Weisbecker <fweisbec@gmail.com> wrote:
> On Thu, Apr 15, 2010 at 04:03:58PM +0200, Ingo Molnar wrote: > > > > > > > > > diff --git a/kernel/lockdep.c b/kernel/lockdep.c > > > index 78325f8..65d4336 100644 > > > --- a/kernel/lockdep.c > > > +++ b/kernel/lockdep.c > > > @@ -2298,7 +2298,11 @@ void trace_hardirqs_on_caller(unsigned long ip) > > > return; > > > > > > if (unlikely(curr->hardirqs_enabled)) { > > > + unsigned long flags; > > > + > > > + raw_local_irq_save(flags); > > > debug_atomic_inc(redundant_hardirqs_on); > > > + raw_local_irq_restore(flags); > > > return; > > > } > > > /* we'll do an OFF -> ON transition: */ > > > > that looks rather ugly. Why not do a raw: > > > > this_cpu_inc(lockdep_stats.redundant_hardirqs_on); > > > > which basically open-codes debug_atomic_inc(), but without the warning? > > > There is also no guarantee we are in a non-preemptable section. We can then > also race against another cpu. > > I'm not sure what to do.
it's a statistics counter so worst-case we lose a count. It's not a real issue - but might be worth adding a comment.
Ingo
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