[PATCH 15/15] perf, tools: Add perf stat --transaction v3

Andi Kleen
2013-04-20T19:19:56Z

Add support to perf stat to print the basic transactional execution statistics:
Total cycles, Cycles in Transaction, Cycles in aborted transsactions
using the intx and intx_checkpoint qualifiers.
Transaction Starts and Elision Starts, to compute the average transaction length.

This is a reasonable overview over the success of the transactions.

Enable with a new --transaction / -T option.

This requires measuring these events in a group, since they depend on each
other.

This is implemented by using TM sysfs events exported by the kernel

v2: Only print the extended statistics when the option is enabled.
This avoids negative output when the user specifies the -T events
in separate groups.
v3: Port to latest tree
Signed-off-by: Andi Kleen <ak@linux.intel.com>
---
tools/perf/Documentation/perf-stat.txt | 5 ++
tools/perf/builtin-stat.c | 103 +++++++++++++++++++++++++++++++-
tools/perf/util/evsel.h | 6 ++
3 files changed, 111 insertions(+), 3 deletions(-)

diff --git a/tools/perf/Documentation/perf-stat.txt b/tools/perf/Documentation/perf-stat.txt
index 2fe87fb..40bc65a 100644
--- a/tools/perf/Documentation/perf-stat.txt
+++ b/tools/perf/Documentation/perf-stat.txt
@@ -132,6 +132,11 @@ is a useful mode to detect imbalance between physical cores. To enable this mod
use --per-core in addition to -a. (system-wide). The output includes the
core number and the number of online logical processors on that physical processor.

+-T::
+--transaction::
+
+Print statistics of transactional execution if supported.
+
EXAMPLES
--------

diff --git a/tools/perf/builtin-stat.c b/tools/perf/builtin-stat.c
index 7e910ba..5053c1a 100644
--- a/tools/perf/builtin-stat.c
+++ b/tools/perf/builtin-stat.c
@@ -70,6 +70,30 @@ static void print_counter_aggr(struct perf_evsel *counter, char *prefix);
static void print_counter(struct perf_evsel *counter, char *prefix);
static void print_aggr(char *prefix);

+/* Default events used for perf stat -T */
+static const char * const transaction_attrs[] = {
+ "task-clock",
+ "{"
+ "instructions,"
+ "cycles,"
+ "cpu/cycles-t/,"
+ "cpu/cycles-ct/,"
+ "cpu/tx-start/,"
+ "cpu/el-start/"
+ "}"
+};
+
+/* must match the transaction_attrs above */
+enum {
+ T_TASK_CLOCK,
+ T_INSTRUCTIONS,
+ T_CYCLES,
+ T_CYCLES_INTX,
+ T_CYCLES_INTX_CP,
+ T_TRANSACTION_START,
+ T_ELISION_START
+};
+
static struct perf_evlist *evsel_list;

static struct perf_target target = {
@@ -90,6 +114,7 @@ static enum aggr_mode aggr_mode = AGGR_GLOBAL;
static pid_t child_pid = -1;
static bool null_run = false;
static int detailed_run = 0;
+static bool transaction_run;
static bool big_num = true;
static int big_num_opt = -1;
static const char *csv_sep = NULL;
@@ -213,7 +238,11 @@ static struct stats runtime_l1_icache_stats[MAX_NR_CPUS];
static struct stats runtime_ll_cache_stats[MAX_NR_CPUS];
static struct stats runtime_itlb_cache_stats[MAX_NR_CPUS];
static struct stats runtime_dtlb_cache_stats[MAX_NR_CPUS];
+static struct stats runtime_cycles_intx_stats[MAX_NR_CPUS];
+static struct stats runtime_cycles_intxcp_stats[MAX_NR_CPUS];
static struct stats walltime_nsecs_stats;
+static struct stats runtime_transaction_stats[MAX_NR_CPUS];
+static struct stats runtime_elision_stats[MAX_NR_CPUS];

static void perf_stat__reset_stats(struct perf_evlist *evlist)
{
@@ -272,6 +301,18 @@ static inline int nsec_counter(struct perf_evsel *evsel)
return 0;
}

+static struct perf_evsel *nth_evsel(int n)
+{
+ struct perf_evsel *ev;
+ int j;
+
+ j = 0;
+ list_for_each_entry(ev, &evsel_list->entries, node)
+ if (j++ == n)
+ return ev;
+ return NULL;
+}
+
/*
* Update various tracking values we maintain to print
* more semantic information such as miss/hit ratios,
@@ -283,8 +324,14 @@ static void update_shadow_stats(struct perf_evsel *counter, u64 *count)
update_stats(&runtime_nsecs_stats[0], count[0]);
else if (perf_evsel__match(counter, HARDWARE, HW_CPU_CYCLES))
update_stats(&runtime_cycles_stats[0], count[0]);
- else if (perf_evsel__match(counter, HARDWARE, HW_STALLED_CYCLES_FRONTEND))
- update_stats(&runtime_stalled_cycles_front_stats[0], count[0]);
+ else if (perf_evsel__cmp(counter, nth_evsel(T_CYCLES_INTX)))
+ update_stats(&runtime_cycles_intx_stats[0], count[0]);
+ else if (perf_evsel__cmp(counter, nth_evsel(T_CYCLES_INTX_CP)))
+ update_stats(&runtime_cycles_intxcp_stats[0], count[0]);
+ else if (perf_evsel__cmp(counter, nth_evsel(T_TRANSACTION_START)))
+ update_stats(&runtime_transaction_stats[0], count[0]);
+ else if (perf_evsel__cmp(counter, nth_evsel(T_ELISION_START)))
+ update_stats(&runtime_elision_stats[0], count[0]);
else if (perf_evsel__match(counter, HARDWARE, HW_STALLED_CYCLES_BACKEND))
update_stats(&runtime_stalled_cycles_back_stats[0], count[0]);
else if (perf_evsel__match(counter, HARDWARE, HW_BRANCH_INSTRUCTIONS))
@@ -807,7 +854,7 @@ static void print_ll_cache_misses(int cpu,

static void abs_printout(int cpu, int nr, struct perf_evsel *evsel, double avg)
{
- double total, ratio = 0.0;
+ double total, ratio = 0.0, total2;
const char *fmt;

if (csv_output)
@@ -903,6 +950,41 @@ static void abs_printout(int cpu, int nr, struct perf_evsel *evsel, double avg)
ratio = 1.0 * avg / total;

fprintf(output, " # %8.3f GHz ", ratio);
+ } else if (perf_evsel__cmp(evsel, nth_evsel(T_CYCLES_INTX)) &&
+ transaction_run) {
+ total = avg_stats(&runtime_cycles_stats[cpu]);
+ if (total)
+ fprintf(output,
+ " # %5.2f%% transactional cycles ",
+ 100.0 * (avg / total));
+ } else if (perf_evsel__cmp(evsel, nth_evsel(T_CYCLES_INTX_CP)) &&
+ transaction_run) {
+ total = avg_stats(&runtime_cycles_stats[cpu]);
+ total2 = avg_stats(&runtime_cycles_intx_stats[cpu]);
+ if (total)
+ fprintf(output,
+ " # %5.2f%% aborted cycles ",
+ 100.0 * ((total2-avg) / total));
+ } else if (perf_evsel__cmp(evsel, nth_evsel(T_TRANSACTION_START)) &&
+ avg > 0 &&
+ runtime_cycles_intx_stats[cpu].n != 0 &&
+ transaction_run) {
+ total = avg_stats(&runtime_cycles_intx_stats[cpu]);
+
+ if (total)
+ ratio = total / avg;
+
+ fprintf(output, " # %8.0f cycles / transaction ", ratio);
+ } else if (perf_evsel__cmp(evsel, nth_evsel(T_ELISION_START)) &&
+ avg > 0 &&
+ runtime_cycles_intx_stats[cpu].n != 0 &&
+ transaction_run) {
+ total = avg_stats(&runtime_cycles_intx_stats[cpu]);
+
+ if (total)
+ ratio = total / avg;
+
+ fprintf(output, " # %8.0f cycles / elision ", ratio);
} else if (runtime_nsecs_stats[cpu].n != 0) {
char unit = 'M';

@@ -1312,6 +1394,19 @@ static int add_default_attributes(void)
if (null_run)
return 0;

+ if (transaction_run) {
+ unsigned i;
+
+ for (i = 0; i < ARRAY_SIZE(transaction_attrs); i++) {
+ if (parse_events(evsel_list, transaction_attrs[i])) {
+ fprintf(stderr,
+ "Cannot set up transaction events\n");
+ return -1;
+ }
+ }
+ return 0;
+ }
+
if (!evsel_list->nr_entries) {
if (perf_evlist__add_default_attrs(evsel_list, default_attrs) < 0)
return -1;
@@ -1397,6 +1492,8 @@ int cmd_stat(int argc, const char **argv, const char *prefix __maybe_unused)
"aggregate counts per processor socket", AGGR_SOCKET),
OPT_SET_UINT(0, "per-core", &aggr_mode,
"aggregate counts per physical processor core", AGGR_CORE),
+ OPT_BOOLEAN('T', "transaction", &transaction_run,
+ "hardware transaction statistics"),
OPT_END()
};
const char * const stat_usage[] = {
diff --git a/tools/perf/util/evsel.h b/tools/perf/util/evsel.h
index 3f156cc..2f3dc86 100644
--- a/tools/perf/util/evsel.h
+++ b/tools/perf/util/evsel.h
@@ -180,6 +180,12 @@ static inline bool perf_evsel__match2(struct perf_evsel *e1,
(e1->attr.config == e2->attr.config);
}

+#define perf_evsel__cmp(a, b) \
+ ((a) && \
+ (b) && \
+ (a)->attr.type == (b)->attr.type && \
+ (a)->attr.config == (b)->attr.config)
+
int __perf_evsel__read_on_cpu(struct perf_evsel *evsel,
int cpu, int thread, bool scale);

--
1.7.7.6