[PATCH] perf stat: Add support for s390 transaction counters

[Thomas Richter]

This patch introduces support for s390 transaction counters
displayed with command 'perf stat -T -- sleep 2'

Right now there is only hard coded support for x86.

This patch introduces architecture specfic counter
tables for x86 and s390. The architecture is queried
and the event string for transaction counters is constructed
depending on the architecture and the CPU measurement
facility counter list.

Output Before:
[root@s35lp76 perf]# perf stat -T -- sleep 1
Cannot set up transaction events
[root@s35lp76 perf]#

Output after:
[root@s35lp76 perf]# ./perf stat -T -- sleep 1

 Performance counter stats for 'sleep 1':

   0.939985      task-clock (msec)         #    0.001 CPUs utilized
  2,557,145      instructions              #    0.53  insn per cycle
  4,785,929      cycles                    #    5.091 GHz
          0      cpum_cf/TX_C_TABORT_NO_SPECIAL/ #    0.000 K/sec
          0      cpum_cf/TX_C_TABORT_SPECIAL/ #    0.000 K/sec
          0      cpum_cf/TX_C_TEND/        #    0.000 K/sec
          0      cpum_cf/TX_NC_TABORT/     #    0.000 K/sec
          0      cpum_cf/TX_NC_TEND/       #    0.000 K/sec

  1.001934710 seconds time elapsed

[root@s35lp76 perf]#

Output on x86 is unchanged.

Signed-off-by: Thomas Richter <tmricht@xxxxxxxxxxxxxxxxxx>
Reviewed--by: Hendrik Brueckner <brueckner@xxxxxxxxxxxxxxxxxx>
---
 tools/perf/builtin-stat.c | 162 ++++++++++++++++++++++++++++++++++++++--------
 1 file changed, 135 insertions(+), 27 deletions(-)

diff --git a/tools/perf/builtin-stat.c b/tools/perf/builtin-stat.c
index 86c8c8a9229c..75b4f1c9cd78 100644
--- a/tools/perf/builtin-stat.c
+++ b/tools/perf/builtin-stat.c
@@ -95,22 +95,8 @@ static const char *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 * transaction_limited_attrs = {
-	"task-clock,"
-	"{"
-	"instructions,"
-	"cycles,"
-	"cpu/cycles-t/,"
-	"cpu/tx-start/"
+	"cycles"
+	"%s"
 	"}"
 };
 
@@ -2149,13 +2135,123 @@ __weak void arch_topdown_group_warn(void)
 {
 }
 
+struct pmu_tx_events {			/* Define transaction counters */
+	const char *pmu;		/* PMU name */
+	const char *name;		/* Counter name */
+};
+
+static struct pmu_tx_events x86_tx_events[] = {/* x86 transaction counters */
+	{
+		.pmu = "cpu",
+		.name = "cycles-t",
+	},
+	{
+		.pmu = "cpu",
+		.name = "tx-start",
+	},
+	{
+		.pmu = "cpu",
+		.name = "el-start",
+	},
+	{
+		.pmu = "cpu",
+		.name = "cycles-ct",
+	},
+	{
+		.pmu = 0
+	}
+};
+
+static struct pmu_tx_events s390_tx_events[] = {/* s390 transaction counters */
+	{
+		.pmu = "cpum_cf",
+		.name = "TX_C_TABORT_NO_SPECIAL",
+	},
+	{
+		.pmu = "cpum_cf",
+		.name = "TX_C_TABORT_SPECIAL",
+	},
+	{
+		.pmu = "cpum_cf",
+		.name = "TX_C_TEND",
+	},
+	{
+		.pmu = "cpum_cf",
+		.name = "TX_NC_TABORT",
+	},
+	{
+		.pmu = "cpum_cf",
+		.name = "TX_NC_TEND",
+	},
+	{
+		.pmu = 0
+	}
+};
+
+struct arch_pmu_tx_events {
+	const char *archname;		/* Architecture name */
+	struct pmu_tx_events *tx;	/* Architecture specific counters */
+} arch_pmu_tx_events[] = {
+	{
+		.archname = "s390",
+		.tx = s390_tx_events
+	},
+	{
+		.archname = "x86",
+		.tx = x86_tx_events
+	},
+	{
+		.archname = 0
+	}
+};
+
+static struct pmu_tx_events *pmu_tx_find_arch(const char *name)
+{
+	struct arch_pmu_tx_events *p = arch_pmu_tx_events;
+
+	for (; p->archname; ++p)
+		if (!strcmp(name, p->archname))
+			return p->tx;
+	return NULL;
+}
+
+/* Search the list of transaction events and test if they are valid for
+ * this PMU. The events are named cpu/cycles-t/ or cpum_cf/TX_NC_TEND/
+ * that is the PMU name followed by the event name surrounded by slashes.
+ *
+ * The function returns a string which contains the tested (and existing)
+ * PMU transaction events. The caller must free this string.
+ *
+ * If no PMU transaction events are found, a NULL pointer is returned.
+ */
+static char *build_tx_string(const char *fmt, struct pmu_tx_events *txp)
+{
+	struct pmu_tx_events *p = txp;
+	char buffer[512], *result;
+	int rc, i = 0;
+
+	memset(buffer, 0, sizeof(buffer));
+	for (p = txp; p->pmu; ++p) {
+		if (pmu_have_event(p->pmu, p->name)) {
+			rc = snprintf(buffer + i, sizeof(buffer) - i, ",%s/%s/",
+				      p->pmu, p->name);
+			i += rc;
+			if (i >= (int)sizeof(buffer))
+				break;
+		}
+	}
+	if (i)			/* Transaction counters found */
+		return asprintf(&result, fmt, buffer) < 0 ? NULL : result;
+	return NULL;
+}
+
 /*
  * Add default attributes, if there were no attributes specified or
  * if -d/--detailed, -d -d or -d -d -d is used:
  */
 static int add_default_attributes(void)
 {
-	int err;
+	int err = -1;
 	struct perf_event_attr default_attrs0[] = {
 
   { .type = PERF_TYPE_SOFTWARE, .config = PERF_COUNT_SW_TASK_CLOCK		},
@@ -2274,20 +2370,32 @@ static int add_default_attributes(void)
 		return 0;
 
 	if (transaction_run) {
-		struct parse_events_error errinfo;
+		struct parse_events_error errinfo = { .str = NULL };
+		char *tx_str;
+		struct pmu_tx_events *tx_archp;
 
-		if (pmu_have_event("cpu", "cycles-ct") &&
-		    pmu_have_event("cpu", "el-start"))
-			err = parse_events(evsel_list, transaction_attrs,
-					   &errinfo);
-		else
-			err = parse_events(evsel_list,
-					   transaction_limited_attrs,
-					   &errinfo);
-		if (err) {
+		/* Find architecture transaction counter string table */
+		tx_archp = pmu_tx_find_arch(perf_env__arch(NULL));
+		if (!tx_archp) {
+			fprintf(stderr, "Cannot set up transaction events\n");
+			return -1;
+		}
+
+		/* Build architecture transaction counter string */
+		tx_str = build_tx_string(transaction_attrs, tx_archp);
+		if (!tx_str) {
 			fprintf(stderr, "Cannot set up transaction events\n");
 			return -1;
 		}
+
+		err = parse_events(evsel_list, tx_str, &errinfo);
+		free(tx_str);
+		if (err) {
+			fprintf(stderr, "Cannot set up transaction events:%s\n",
+				errinfo.str);
+			free(errinfo.str);
+			return -1;
+		}
 		return 0;
 	}
 
-- 
2.14.3