perf, x86: Catch spurious interrupts after disabling counters

perf, x86: Catch spurious interrupts after disabling counters

Some cpus still deliver spurious interrupts after disabling a
counter. This caused 'undelivered NMI' messages. This patch
fixes this. Introduced by:

  4177c42: perf, x86: Try to handle unknown nmis with an enabled PMU

Reported-by: Ingo Molnar <[email protected]>
Signed-off-by: Robert Richter <[email protected]>
Cc: Don Zickus <[email protected]>
Cc: [email protected] <[email protected]>
Cc: [email protected] <[email protected]>
Cc: [email protected] <[email protected]>
Cc: [email protected] <[email protected]>
Cc: [email protected] <[email protected]>
Cc: [email protected] <[email protected]>
Cc: [email protected] <[email protected]>
Cc: Peter Zijlstra <[email protected]>
LKML-Reference: <20100915162034[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>