init: Introduce SYSTEM_SCHEDULING state

init: Introduce SYSTEM_SCHEDULING state

might_sleep() debugging and smp_processor_id() debugging should be active
right after the scheduler starts working. The init task can invoke
smp_processor_id() from preemptible context as it is pinned on the boot cpu
until sched_smp_init() removes the pinning and lets it schedule on all non
isolated cpus.

Add a new state which allows to enable those checks earlier and add it to
the xen do_poweroff() function.

No functional change.

Tested-by: Mark Rutland <[email protected]>
Signed-off-by: Thomas Gleixner <[email protected]>
Signed-off-by: Peter Zijlstra (Intel) <[email protected]>
Reviewed-by: Boris Ostrovsky <[email protected]>
Acked-by: Mark Rutland <[email protected]>
Cc: Greg Kroah-Hartman <[email protected]>
Cc: Juergen Gross <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Steven Rostedt <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Ingo Molnar <[email protected]>