Messages in this thread | | | Date | Tue, 28 Mar 2017 21:18:29 -0700 | From | Andi Kleen <> | Subject | Re: [PATCH V4 2/2] perf/x86: add sysfs entry to freeze counter on SMI |
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> + if (x86_pmu.attr_freeze_on_smi == val) > + return count; > + > + mutex_lock(&freeze_on_smi_mutex);
I don't think the mutex is really needed, but if it was it would need to include the previous check too to be atomic.
> + > + get_online_cpus(); > + > + flip_smm_bit(&val); > + smp_call_function(flip_smm_bit, &val, 1); > + > + put_online_cpus();
This is on_each_cpu()
> + > + x86_pmu.attr_freeze_on_smi = val; > + > + mutex_unlock(&freeze_on_smi_mutex);
-Andi
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