----- On Nov 14, 2017, at 3:04 PM, Mathieu Desnoyers mathieu.desnoyers-vg+e7yoeK/dWk0Htik3J/w@public.gmane.org wrote:
[...]

+	if (!fallback) {
+		smp_call_function_many(tmpmask, ipi_mb, NULL, 1);
+		free_cpumask_var(tmpmask);
+	}

Testing with preempt debugging options showed that I need to
disable preemption around smp_call_function_many(). The membarrier
private expedited command in 4.14 is also affected. I will add a
fix to the series covering that case separately, and CC stable.

Thanks,

Mathieu

-- 
Mathieu Desnoyers
EfficiOS Inc.
http://www.efficios.com