Re: [RFC PATCH for 4.15 18/24] membarrier: provide SHARED_EXPEDITED command

From: Mathieu Desnoyers
Date: Tue Nov 14 2017 - 20:36:02 EST


----- 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