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From: Mathieu Desnoyers <mathieu.desnoyers-vg+e7yoeK/dWk0Htik3J/w@public.gmane.org>
Subject: Re: [RFC PATCH for 4.15 18/24] membarrier: provide SHARED_EXPEDITED
 command
Date: Wed, 15 Nov 2017 01:36:11 +0000 (UTC)
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References: <20171114200414.2188-1-mathieu.desnoyers@efficios.com> <20171114200414.2188-19-mathieu.desnoyers@efficios.com>
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----- 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