Messages in this thread | | | Subject | Re: [PATCH tip/core/rcu 3/4] rcu: stop spurious warnings from synchronize_sched_expedited | From | Peter Zijlstra <> | Date | Tue, 21 Feb 2012 19:00:17 +0100 |
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On Tue, 2012-02-21 at 09:58 -0800, Paul E. McKenney wrote: > From: Hugh Dickins <hughd@google.com> > > synchronize_sched_expedited() is spamming CONFIG_DEBUG_PREEMPT=y > users with an unintended warning from the cpu_is_offline() check: > use raw_smp_processor_id() instead of smp_processor_id() there.
This fails to mention why it makes sense to test a random cpu for offline-ness..
> Signed-off-by: Hugh Dickins <hughd@google.com> > Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> > --- > kernel/rcutree.c | 2 +- > 1 files changed, 1 insertions(+), 1 deletions(-) > > diff --git a/kernel/rcutree.c b/kernel/rcutree.c > index eacc10b..1050d6d 100644 > --- a/kernel/rcutree.c > +++ b/kernel/rcutree.c > @@ -2014,7 +2014,7 @@ void synchronize_sched_expedited(void) > /* Note that atomic_inc_return() implies full memory barrier. */ > firstsnap = snap = atomic_inc_return(&sync_sched_expedited_started); > get_online_cpus(); > - WARN_ON_ONCE(cpu_is_offline(smp_processor_id())); > + WARN_ON_ONCE(cpu_is_offline(raw_smp_processor_id())); > > /* > * Each pass through the following loop attempts to force a
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