Re: 50 Watt idle power regression bisected to Linux-3.10

[H. Peter Anvin]

On 12/12/2013 05:28 AM, Ingo Molnar wrote:
>>
>> The reason we use thread_info::flags is because we need to write
>> TIF_NEED_RESCHED into it to wake up anyhow.
>>
>> Using another cacheline would mean the wakeup path would need to write a
>> second cross cpu cacheline -- that is badness too.
>>
>> So no, I don't think we want to listen to another line.
> 

Right, okay, so that's the implicit wakeup.  However, I would think the
CLFLUSH would hurt a lot more.

	-hpa


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