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

From: Ingo Molnar
Date: Wed Dec 11 2013 - 10:09:22 EST



* Thomas Gleixner <tglx@xxxxxxxxxxxxx> wrote:

> On Wed, 11 Dec 2013, Ingo Molnar wrote:
> >
> > Another thing that is required I think is to issue a write barrier
> > before CLFLUSH instruction. By my (possibly incorrect ...) reading of
> > the documentation CLFLUSH does not appear to be ordered (at all), so
> > it might execute before the modification to the affected memory?
>
> We already have a write barrier in the code which modifies
> current_thread_info()->flags.

Which code is that, could you please cite it? (I tried finding it but
my grep-fu failed me.)

Thanks,

Ingo
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