Re: [RFC PATCH 2/3 v3] perf: Implement Nehalem uncore pmu

From: Stephane Eranian
Date: Mon Dec 13 2010 - 14:04:14 EST


On Mon, Dec 13, 2010 at 5:51 PM, Andi Kleen <andi@xxxxxxxxxxxxxx> wrote:
>> If think there you want something like:
>>
>> if (cpu == cpumask_first(topology_core_siblings(cpu)) {
>> Â Â Â rdmsrl(MSR_IA32_DEBUGCTLMSR, val);
>> ÂÂ Â wrmsrl(MSR_IA32_DEBUGCTLMSR, val | DEBUGCTLMSR_ENABLE_UNCORE_PMI);
>> }
>
> You have to be careful with hotplug. The code would need to be rerun
> on hotplug. Otherwise the interrupt may end up on a downed CPU.

That is true.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/