rcu: more careful check for the last non-dyntick-idle CPU
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From: Paul E. McKenney on 30 Mar 2010 12:00 On Tue, Mar 30, 2010 at 06:40:36PM +0800, Lai Jiangshan wrote: > Warning: I just did build test. > > Subject: [PATCH] rcu: more careful check for the last non-dyntick-idle CPU > > If a CPU is not in nohz_cpu_mask, it does not means this > CPU is a non-dyntick-idle CPU, because this CPU may be offline or not exist. Good catch, queued, thank you! Thanx, Paul > Signed-off-by: Lai Jiangshan <laijs(a)cn.fujitsu.com> > --- > diff --git a/kernel/rcutree_plugin.h b/kernel/rcutree_plugin.h > index 4befb64..6086a7d 100644 > --- a/kernel/rcutree_plugin.h > +++ b/kernel/rcutree_plugin.h > @@ -1026,7 +1026,7 @@ int rcu_needs_cpu(int cpu) > > /* Don't bother unless we are the last non-dyntick-idle CPU. */ > for_each_cpu_not(thatcpu, nohz_cpu_mask) > - if (thatcpu != cpu) { > + if (cpu_online(thatcpu) && thatcpu != cpu) { > per_cpu(rcu_dyntick_drain, cpu) = 0; > per_cpu(rcu_dyntick_holdoff, cpu) = jiffies - 1; > return rcu_needs_cpu_quick_check(cpu); -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo(a)vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/ |