perf, x86: Add parts of the remaining haswell PMU functionality v2

From: Andi Kleen <[email protected]>

Add support to perf stat to print the basic transactional execution statistics:
Total cycles, Cycles in Transaction, Cycles in aborted transsactions using the in_tx and in_tx_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 <[email protected]>

---
 tools/perf/Documentation/perf-stat.txt |   5 ++
 tools/perf/builtin-stat.c              | 132 ++++++++++++++++++++++++++++++++-
 tools/perf/util/evsel.h                |   6 ++
 tools/perf/util/pmu.c                  |  16 ++++
 tools/perf/util/pmu.h                  |   1 +
 5 files changed, 157 insertions(+), 3 deletions(-)

From: Andi Kleen <[email protected]>

Add support to perf stat to print the basic transactional execution statistics:
Total cycles, Cycles in Transaction, Cycles in aborted transsactions using the in_tx and in_tx_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 <[email protected]>

---
 tools/perf/Documentation/perf-stat.txt |   5 ++
 tools/perf/builtin-stat.c              | 132 ++++++++++++++++++++++++++++++++-
 tools/perf/util/evsel.h                |   6 ++
 tools/perf/util/pmu.c                  |  16 ++++
 tools/perf/util/pmu.h                  |   1 +
 5 files changed, 157 insertions(+), 3 deletions(-)

tools/perf/Documentation/perf-stat.txt +5 -0

index 2fe87fb..40bc65a 100644
@@ -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
 --------
 

tools/perf/builtin-stat.c +16 -0

index 352fbd7..d68bf93 100644
@@ -46,6 +46,7 @@
 #include "util/util.h"
 #include "util/parse-options.h"
 #include "util/parse-events.h"
+#include "util/pmu.h"
 #include "util/event.h"
 #include "util/evlist.h"
 #include "util/evsel.h"

@@ -70,6 +71,41 @@ 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/tx-start/,"
+	"cpu/el-start/,"
+	"cpu/cycles-ct/"
+	"}"
+};
+
+/* More limited version when the CPU does not have all events. */
+static const char * const transaction_limited_attrs[] = {

tools/perf/builtin-stat.c +10 -0

 static struct perf_evlist	*evsel_list;
 
 static struct perf_target	target = {

@@ -90,6 +126,7 @@ static enum aggr_mode		aggr_mode			= AGGR_GLOBAL;
 static volatile 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 +250,10 @@ 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_in_tx_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)
 {

@@ -235,6 +275,11 @@ static void perf_stat__reset_stats(struct perf_evlist *evlist)
 	memset(runtime_ll_cache_stats, 0, sizeof(runtime_ll_cache_stats));
 	memset(runtime_itlb_cache_stats, 0, sizeof(runtime_itlb_cache_stats));
 	memset(runtime_dtlb_cache_stats, 0, sizeof(runtime_dtlb_cache_stats));
+	memset(runtime_cycles_in_tx_stats, 0,
+			sizeof(runtime_cycles_in_tx_stats));
+	memset(runtime_transaction_stats, 0,
+		sizeof(runtime_transaction_stats));
+	memset(runtime_elision_stats, 0, sizeof(runtime_elision_stats));
 	memset(&walltime_nsecs_stats, 0, sizeof(walltime_nsecs_stats));
 }
 

@@ -272,6 +317,18 @@ static inline int nsec_counter(struct perf_evsel *evsel)
 	return 0;
 }
 
+static struct perf_evsel *nth_evsel(int n)

tools/perf/builtin-stat.c +7 -1

+	else if (perf_evsel__cmp(counter, nth_evsel(T_CYCLES_IN_TX)))
+		update_stats(&runtime_cycles_in_tx_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 +868,7 @@ 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)

tools/perf/builtin-stat.c +37 -0

+		   avg > 0 &&
+		   runtime_cycles_in_tx_stats[cpu].n != 0 &&
+		   transaction_run) {
+		total = avg_stats(&runtime_cycles_in_tx_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';
 

@@ -1216,6 +1314,16 @@ static int perf_stat_init_aggr_mode(void)
 	return 0;
 }
 
+static int setup_events(const char * const *attrs, unsigned len)
+{
+	unsigned i;
+
+	for (i = 0; i < len; i++) {
+		if (parse_events(evsel_list, attrs[i]))
+			return -1;
+	}
+	return 0;
+}
 
 /*
  * Add default attributes, if there were no attributes specified or

@@ -1334,6 +1442,22 @@ static int add_default_attributes(void)
 	if (null_run)
 		return 0;
 
+	if (transaction_run) {
+		int err;
+		if (pmu_have_event("cpu", "cycles-ct") &&
+		    pmu_have_event("cpu", "el-start"))
+			err = setup_events(transaction_attrs,
+					ARRAY_SIZE(transaction_attrs));
+		else
+				err = setup_events(transaction_limited_attrs,
+				 ARRAY_SIZE(transaction_limited_attrs));
+		if (err < 0) {
+			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;

@@ -1419,6 +1543,8 @@ 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[] = {

tools/perf/util/evsel.h +6 -0

index 3f156cc..2f3dc86 100644
@@ -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);
 

tools/perf/util/pmu.c +16 -0

index bc9d806..64362fe 100644
@@ -637,3 +637,19 @@ void print_pmu_events(const char *event_glob, bool name_only)
 		printf("\n");
 	free(aliases);
 }
+
+bool pmu_have_event(const char *pname, const char *name)
+{
+	struct perf_pmu *pmu;
+	struct perf_pmu_alias *alias;
+
+	pmu = NULL;
+	while ((pmu = perf_pmu__scan(pmu)) != NULL) {
+		if (strcmp(pname, pmu->name))
+			continue;
+		list_for_each_entry(alias, &pmu->aliases, list)
+			if (!strcmp(alias->name, name))
+				return true;
+	}
+	return false;
+}

tools/perf/util/pmu.h +1 -0

index 6b2cbe2..1179b26 100644
@@ -42,6 +42,7 @@ int perf_pmu__format_parse(char *dir, struct list_head *head);
 struct perf_pmu *perf_pmu__scan(struct perf_pmu *pmu);
 
 void print_pmu_events(const char *event_glob, bool name_only);
+bool pmu_have_event(const char *pname, const char *name);
 
 int perf_pmu__test(void);
 #endif /* __PMU_H */

Signature · 1 line

1.8.3.1

Quoted 19 lines

tools/perf/builtin-stat.c +19 -0

+/* Default events used for perf stat -T */
+static const char * const transaction_attrs[] = {
+	"task-clock",
+	"{"
+	"instructions,"
+	"cycles,"
+	"cpu/cycles-t/,"
+	"cpu/tx-start/,"
+	"cpu/el-start/,"
+	"cpu/cycles-ct/"
+	"}"
+};
+
+/* More limited version when the CPU does not have all events. */
+static const char * const transaction_limited_attrs[] = {
+	"task-clock",
+	"{"
+	"instructions,"
+	"cycles,"

tools/perf/builtin-stat.c static void print_counter_aggr(struct perf_evsel *counter, char *prefix); · line 98

Quoted 6 lines

tools/perf/builtin-stat.c +6 -0

+	"cpu/cycles-t/,"
+	"cpu/tx-start/"
+	"}"
+};
+
+/* must match the transaction_attrs above */

Match in what way? It kinda matches the first one (transaction_attrs):

enum {
	T_TASK_CLOCK,        ==	"task-clock",
	T_INSTRUCTIONS,      == "instructions,"
	T_CYCLES,	     == "cycles,"
	T_CYCLES_IN_TX,      ~= "cpu/cycles-t/,"
	T_TRANSACTION_START, != "cpu/tx-start/,"
	T_ELISION_START,     ~= "cpu/el-start/,"
	T_CYCLES_IN_TX_CP,   != "cpu/cycles-ct/"
};

Also the enum numbers won't match the array positions due to the '{' grouping (?) entries, so, without looking further, how can this match? Reading on...

Anyways I use this option pretty heavily and the results are good to my knowledge.

tools/perf/builtin-stat.c static void update_shadow_stats(struct perf_evsel *counter, u64 *count) · line 287

Quoted 8 lines

* Update various tracking values we maintain to print
* more semantic information such as miss/hit ratios,

tools/perf/builtin-stat.c +0 -2

@@ -283,8 +340,12 @@ 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]);

Why remove the test for HW_STALLED_CYCLES_FRONTEND?

Got it why it doesn't need to account for the '{' in the array ;-)

While this works and isn't in any fast path, I find it ugly with all this looping in nth_evsel.

Why not:

	} else if (evsel->idx == T_CYCLES_IN_TX)) &&

? I guess this works as you expect, no?

Quoted 10 lines

tools/perf/builtin-stat.c static void update_shadow_stats(struct perf_evsel *counter, u64 *count) · line 287

Quoted 8 lines

* Update various tracking values we maintain to print
* more semantic information such as miss/hit ratios,

tools/perf/builtin-stat.c +0 -2

@@ -283,8 +340,12 @@ 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]);

Why remove the test for HW_STALLED_CYCLES_FRONTEND?

Hmm that was probably a merge error.

I'll fix & resend.

Quoted 5 lines

Got it why it doesn't need to account for the '{' in the array ;-)

While this works and isn't in any fast path, I find it ugly with all this looping in nth_evsel.

Quoted 5 lines

Why not:

	} else if (evsel->idx == T_CYCLES_IN_TX)) &&

? I guess this works as you expect, no?

I had some problems with people using -T, but also setting custom events, that is why I added the extra comparison

The event lists are small enough that it's not really noticeable. I suppose could set up an array once.

Em Thu, Aug 15, 2013 at 06:42:03PM +0200, Andi Kleen escreveu:

Quoted 2 lines

Here's an updated patch.

Review int cmd_stat(int argc, const char **argv, const char *prefix __maybe_unused) · line 1564

Quoted 8 lines

perf, tools: Add perf stat --transaction v4

(quoted diff) +2 -0

@@ -1419,6 +1559,8 @@ 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()

Clashes with another patch, from you, that is in Ingo's perf/core as well, that adds -D, so the above hunk doesn't apply: