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authorAndi Kleen <ak@linux.intel.com>2015-02-27 09:48:30 -0800
committerIngo Molnar <mingo@kernel.org>2015-04-02 17:33:16 +0200
commit8882edf735738c949aba4b65d3ec3453066bab12 (patch)
tree03672541d9447ef25d53e568cba669dfb2e94ad8 /arch/x86/kernel/cpu
parentb37609c30e41264c4df4acff78abfc894499a49b (diff)
perf/x86/intel: Reset more state in PMU reset
The PMU reset code didn't quite keep up with newer PMU features. Improve it a bit to really reset a modern PMU: - Clear all overflow status - Clear LBRs and freezing state - Disable fixed counters too Signed-off-by: Andi Kleen <ak@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: eranian@google.com Link: http://lkml.kernel.org/r/1425059312-18217-2-git-send-email-andi@firstfloor.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch/x86/kernel/cpu')
-rw-r--r--arch/x86/kernel/cpu/perf_event_intel.c12
1 files changed, 12 insertions, 0 deletions
diff --git a/arch/x86/kernel/cpu/perf_event_intel.c b/arch/x86/kernel/cpu/perf_event_intel.c
index 6ea61a572fb0..59994602bb94 100644
--- a/arch/x86/kernel/cpu/perf_event_intel.c
+++ b/arch/x86/kernel/cpu/perf_event_intel.c
@@ -1538,6 +1538,18 @@ static void intel_pmu_reset(void)
if (ds)
ds->bts_index = ds->bts_buffer_base;
+ /* Ack all overflows and disable fixed counters */
+ if (x86_pmu.version >= 2) {
+ intel_pmu_ack_status(intel_pmu_get_status());
+ wrmsrl(MSR_CORE_PERF_GLOBAL_CTRL, 0);
+ }
+
+ /* Reset LBRs and LBR freezing */
+ if (x86_pmu.lbr_nr) {
+ update_debugctlmsr(get_debugctlmsr() &
+ ~(DEBUGCTLMSR_FREEZE_LBRS_ON_PMI|DEBUGCTLMSR_LBR));
+ }
+
local_irq_restore(flags);
}