Always use NMI for performance-monitoring interrupt as there could be
racy situations if we switch between irq and nmi mode frequently.
Signed-off-by: NYong Wang <yong.y.wang@intel.com>
LKML-Reference: <20090529052835.GA13657@ywang-moblin2.bj.intel.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>