----- On Nov 14, 2017, at 3:04 PM, Mathieu Desnoyers mathieu.desnoyers@xxxxxxxxxxxx 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 -- To unsubscribe from this list: send the line "unsubscribe linux-api" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html