Merge branch 'smp/threadalloc' into smp/hotplug

Reason: Pull in the separate branch which was created so arch/tile can
base further work on it.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

diff --cc arch/arm/Kconfig
Simple merge

diff --cc arch/arm/kernel/smp.c
Simple merge

diff --cc arch/x86/xen/smp.c
Simple merge

diff --cc kernel/sched/core.c
Simple merge