1 files changed, 26 insertions, 0 deletions

diff --git a/arch/x86/kernel/cpu/perf_counter.c b/arch/x86/kernel/cpu/perf_counter.c
index ece3813c7a3c..2eeaa99add1c 100644
--- a/arch/x86/kernel/cpu/perf_counter.c
+++ b/arch/x86/kernel/cpu/perf_counter.c
@@ -724,6 +724,30 @@ static void intel_pmu_save_and_restart(struct perf_counter *counter)
                 intel_pmu_enable_counter(hwc, idx);
 }
 
+static void intel_pmu_reset(void)
+{
+        unsigned long flags;
+        int idx;
+
+        if (!x86_pmu.num_counters)
+                return;
+
+        local_irq_save(flags);
+
+        printk("clearing PMU state on CPU#%d\n", smp_processor_id());
+
+        for (idx = 0; idx < x86_pmu.num_counters; idx++) {
+                checking_wrmsrl(x86_pmu.eventsel + idx, 0ull);
+                checking_wrmsrl(x86_pmu.perfctr  + idx, 0ull);
+        }
+        for (idx = 0; idx < x86_pmu.num_counters_fixed; idx++) {
+                checking_wrmsrl(MSR_ARCH_PERFMON_FIXED_CTR0 + idx, 0ull);
+        }
+
+        local_irq_restore(flags);
+}
+
+
 /*
  * This handler is triggered by the local APIC, so the APIC IRQ handling
  * rules apply:
@@ -750,6 +774,8 @@ again:
         if (++loops > 100) {
                 WARN_ONCE(1, "perfcounters: irq loop stuck!\n");
                 perf_counter_print_debug();
+                intel_pmu_reset();
+                perf_enable();
                 return 1;
         }