Messages in this thread | | | Date | Mon, 9 Nov 2015 22:45:12 +0100 | From | Peter Zijlstra <> | Subject | Re: [RFC PATCH 0/3] CFS idle injection |
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On Mon, Nov 09, 2015 at 01:23:04PM -0800, Jacob Pan wrote: > what is WFI?
Wait For Interrupt; very like the x86 HLT thing.
> For Intel, idle states are hints to the HW. The FW decides how far the > idle can go based on many factors, device states included, some are > visible to the OS some are not. We just to help mature such deep idle > conditions.
On some ARM you have to manually orchestrate cluster idle, which is clustered idle states in cpuidle. The up-side is that you explicitly know about them, the down side is that its cross CPU bits and a freak show (think doing cross CPU atomics while a CPU isn't in the coherency domain yet).
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