Add helper to get rid of the ever repeating:

    preempt_enable_no_resched();
    schedule();
    preempt_disable();

patterns.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Acked-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/n/tip-wxx7btox7coby6ifv5vzhzgp@git.kernel.orgSigned-off-by: NIngo Molnar <mingo@elte.hu>