selftests/powerpc: context_switch use private futexes with threads

[Michael Ellerman]

On Sun, 2017-06-04 at 12:06:22 UTC, Nicholas Piggin wrote:
> This reduces overhead of mutex locking and increases context switch
> rate significantly (which helps to measure and profile the context
> switch path).
> 
> Signed-off-by: Nicholas Piggin <npiggin at gmail.com>

Applied to powerpc next, thanks.

https://git.kernel.org/powerpc/c/b27ce776852078df9e14a223b375db

cheers