powerpc/pseries/cpuidle: add polling idle for shared processor guests

[Michael Ellerman]

On Tue, 2017-10-10 at 07:11:09 UTC, Nicholas Piggin wrote:
> For shared processor guests (e.g., KVM), add an idle polling mode rather
> than immediately returning to the hypervisor when the guest CPU goes
> idle.
> 
> Test setup is a 2 socket POWER9 with 4 guests running, each with vCPUs
> equal to 1/2 of real of CPUs. Saturated each guest with tbench. Using
> polling idle gives about 1.4x throughput.
> 
> Kernel compile speed was not changed significantly.
> 
> Signed-off-by: Nicholas Piggin <npiggin at gmail.com>

Applied to powerpc next, thanks.

https://git.kernel.org/powerpc/c/f2ac428e0edabbca41b9dfe9473a90

cheers