On Fri, Jul 14, 2017 at 08:52:28AM -0700, Arjan van de Ven wrote: > On 7/14/2017 8:38 AM, Peter Zijlstra wrote: > > No, that's wrong. We want to fix the normal C state selection process to > > pick the right C state. > > > > The fast-idle criteria could cut off a whole bunch of available C > > states. We need to understand why our current C state pick is wrong and > > amend the algorithm to do better. Not just bolt something on the side. > > I can see a fast path through selection if you know the upper bound of any > selection is just 1 state. > > But also, how much of this is about "C1 be fast" versus "selecting C1 is slow"
I got the impression its about we need to select C1 for longer. But the fact that the patches don't in fact answer any of these questions, they're wrong in principle ;-)