Messages in this thread | | | Date | Wed, 11 Dec 2013 18:48:27 +0100 | From | Ingo Molnar <> | Subject | Re: 50 Watt idle power regression bisected to Linux-3.10 |
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* Peter Zijlstra <peterz@infradead.org> wrote:
> On Wed, Dec 11, 2013 at 04:09:11PM +0100, Ingo Molnar wrote: > > > > * Thomas Gleixner <tglx@linutronix.de> 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.) > > current_set_polling_and_test().
Thx, those variants have the right barrier indeed.
Thanks,
Ingo
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