[tip:perf/stat] perf events: Add stalled cycles generic event - PERF_COUNT_HW_STALLED_CYCLES

From: tip-bot for Ingo Molnar
Date: Wed Apr 27 2011 - 11:59:03 EST


Commit-ID: 94403f8863d0d1d2005291b2ef0719c2534aa303
Gitweb: http://git.kernel.org/tip/94403f8863d0d1d2005291b2ef0719c2534aa303
Author: Ingo Molnar <mingo@xxxxxxx>
AuthorDate: Sun, 24 Apr 2011 08:18:31 +0200
Committer: Ingo Molnar <mingo@xxxxxxx>
CommitDate: Tue, 26 Apr 2011 20:04:53 +0200

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@xxxxxxxxx>
Acked-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
Cc: Frederic Weisbecker <fweisbec@xxxxxxxxx>
Link: http://lkml.kernel.org/n/tip-fue11vymwqsoo5to72jxxjyl@xxxxxxxxxxxxxx
Signed-off-by: Ingo Molnar <mingo@xxxxxxx>
---
arch/x86/kernel/cpu/perf_event_intel.c | 3 +++
include/linux/perf_event.h | 1 +
tools/perf/util/parse-events.c | 1 +
tools/perf/util/python.c | 1 +
4 files changed, 6 insertions(+), 0 deletions(-)

diff --git a/arch/x86/kernel/cpu/perf_event_intel.c b/arch/x86/kernel/cpu/perf_event_intel.c
index 9ae4a2a..efa2704 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
diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h
index ee9f1e7..ac636dd 100644
--- a/include/linux/perf_event.h
+++ b/include/linux/perf_event.h
@@ -52,6 +52,7 @@ enum perf_hw_id {
PERF_COUNT_HW_BRANCH_INSTRUCTIONS = 4,
PERF_COUNT_HW_BRANCH_MISSES = 5,
PERF_COUNT_HW_BUS_CYCLES = 6,
+ PERF_COUNT_HW_STALLED_CYCLES = 7,

PERF_COUNT_HW_MAX, /* non-ABI */
};
diff --git a/tools/perf/util/parse-events.c b/tools/perf/util/parse-events.c
index 952b4ae..1869e4c 100644
--- a/tools/perf/util/parse-events.c
+++ b/tools/perf/util/parse-events.c
@@ -38,6 +38,7 @@ static struct event_symbol event_symbols[] = {
{ CHW(BRANCH_INSTRUCTIONS), "branch-instructions", "branches" },
{ CHW(BRANCH_MISSES), "branch-misses", "" },
{ CHW(BUS_CYCLES), "bus-cycles", "" },
+ { CHW(STALLED_CYCLES), "stalled-cycles", "" },

{ CSW(CPU_CLOCK), "cpu-clock", "" },
{ CSW(TASK_CLOCK), "task-clock", "" },
diff --git a/tools/perf/util/python.c b/tools/perf/util/python.c
index f5e3845..406f613 100644
--- a/tools/perf/util/python.c
+++ b/tools/perf/util/python.c
@@ -798,6 +798,7 @@ static struct {
{ "COUNT_HW_BRANCH_INSTRUCTIONS", PERF_COUNT_HW_BRANCH_INSTRUCTIONS },
{ "COUNT_HW_BRANCH_MISSES", PERF_COUNT_HW_BRANCH_MISSES },
{ "COUNT_HW_BUS_CYCLES", PERF_COUNT_HW_BUS_CYCLES },
+ { "COUNT_HW_STALLED_CYCLES", PERF_COUNT_HW_STALLED_CYCLES },
{ "COUNT_HW_CACHE_L1D", PERF_COUNT_HW_CACHE_L1D },
{ "COUNT_HW_CACHE_L1I", PERF_COUNT_HW_CACHE_L1I },
{ "COUNT_HW_CACHE_LL", PERF_COUNT_HW_CACHE_LL },
--
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