perf, x86: P4 PMU - Don't forget to clear cpuc->active_mask on overflow

It's not enough to simply disable event on overflow the
cpuc->active_mask should be cleared as well otherwise counter
may stall in "active" even in real being already disabled (which
potentially may lead to the situation that user may not use this
counter further).

Don pointed out that:

 " I also noticed this patch fixed some unknown NMIs
   on a P4 when I stressed the box".

Tested-by: Lin Ming <ming.m.lin@intel.com>
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Acked-by: Don Zickus <dzickus@redhat.com>
Signed-off-by: Don Zickus <dzickus@redhat.com>
Cc: Cyrill Gorcunov <gorcunov@gmail.com>
Link: http://lkml.kernel.org/r/1303398203-2918-3-git-send-email-dzickus@redhat.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>

diff --git a/arch/x86/kernel/cpu/perf_event_p4.c b/arch/x86/kernel/cpu/perf_event_p4.c
index c2520e178d32147fd9e2acd954d59e4217115add..d1f77e2934a181155c252bb549c43a6f802d8394 100644 (file)
--- a/arch/x86/kernel/cpu/perf_event_p4.c
+++ b/arch/x86/kernel/cpu/perf_event_p4.c
@@ -947,7 +947,7 @@ static int p4_pmu_handle_irq(struct pt_regs *regs)
                if (!x86_perf_event_set_period(event))
                        continue;
                if (perf_event_overflow(event, 1, &data, regs))
-                       p4_pmu_disable_event(event);
+                       x86_pmu_stop(event, 0);
        }
 
        if (handled) {