perf events: Add stalled cycles generic event - PERF_COUNT_HW_STALLED_CYCLES

The new PERF_COUNT_HW_STALLED_CYCLES event tries to approximate
cycles the CPU does nothing useful, because it is stalled on a
cache-miss or some other condition.

Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Link: http://lkml.kernel.org/n/tip-fue11vymwqsoo5to72jxxjyl@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 3 insertions, 0 deletions

diff --git a/arch/x86/kernel/cpu/perf_event_intel.c b/arch/x86/kernel/cpu/perf_event_intel.c
index 9ae4a2aa7398..efa2704c9dfd 100644
--- a/arch/x86/kernel/cpu/perf_event_intel.c
+++ b/arch/x86/kernel/cpu/perf_event_intel.c
@@ -1413,6 +1413,9 @@ static __init int intel_pmu_init(void)
                 x86_pmu.enable_all = intel_pmu_nhm_enable_all;
                 x86_pmu.extra_regs = intel_nehalem_extra_regs;
 
+                /* Install the stalled-cycles event: 0xff: All reasons, 0xa2: Resource stalls */
+                intel_perfmon_event_map[PERF_COUNT_HW_STALLED_CYCLES] = 0xffa2;
+
                 if (ebx & 0x40) {
                         /*
                          * Erratum AAJ80 detected, we work it around by using