[PATCH v5 09/11] perf/tools: Enhance JSON/metric infrastructure to handle "?"

[Kajol Jain <kjain@linux.ibm.com>]

Patch enhances current metric infrastructure to handle "?" in the metric
expression. The "?" can be use for parameters whose value not known while
creating metric events and which can be replace later at runtime to
the proper value. It also add flexibility to create multiple events out
of single metric event added in json file.

Patch adds function 'arch_get_runtimeparam' which is a arch specific
function, returns the count of metric events need to be created.
By default it return 1.

One loop is added in function 'metricgroup__add_metric_runtime_param',
which create multiple events at run time depend on return value of
'arch_get_runtimeparam' and merge that event in 'group_list'.

This infrastructure needed for hv_24x7 socket/chip level events.
"hv_24x7" chip level events needs specific chip-id to which the
data is requested. Function 'arch_get_runtimeparam' implemented
in header.c which extract number of sockets from sysfs file
"sockets" under "/sys/devices/hv_24x7/interface/".

Signed-off-by: Kajol Jain <kjain@linux.ibm.com>
---
 tools/perf/arch/powerpc/util/header.c | 10 ++++
 tools/perf/tests/expr.c               |  8 ++--
 tools/perf/util/expr.c                | 11 +++--
 tools/perf/util/expr.h                |  5 +-
 tools/perf/util/expr.l                | 27 ++++++++---
 tools/perf/util/metricgroup.c         | 66 ++++++++++++++++++++++++++-
 tools/perf/util/metricgroup.h         |  1 +
 tools/perf/util/stat-shadow.c         | 12 ++++-
 8 files changed, 119 insertions(+), 21 deletions(-)

diff --git a/tools/perf/arch/powerpc/util/header.c b/tools/perf/arch/powerpc/util/header.c
index 3b4cdfc5efd6..dcc3c6ab2e67 100644
--- a/tools/perf/arch/powerpc/util/header.c
+++ b/tools/perf/arch/powerpc/util/header.c
@@ -7,6 +7,8 @@
 #include <string.h>
 #include <linux/stringify.h>
 #include "header.h"
+#include "metricgroup.h"
+#include <api/fs/fs.h>
 
 #define mfspr(rn)       ({unsigned long rval; \
 			 asm volatile("mfspr %0," __stringify(rn) \
@@ -16,6 +18,8 @@
 #define PVR_VER(pvr)    (((pvr) >>  16) & 0xFFFF) /* Version field */
 #define PVR_REV(pvr)    (((pvr) >>   0) & 0xFFFF) /* Revison field */
 
+#define SOCKETS_INFO_FILE_PATH "/devices/hv_24x7/interface/sockets"
+
 int
 get_cpuid(char *buffer, size_t sz)
 {
@@ -44,3 +48,9 @@ get_cpuid_str(struct perf_pmu *pmu __maybe_unused)
 
 	return bufp;
 }
+
+int arch_get_runtimeparam(void)
+{
+	int count;
+	return sysfs__read_int(SOCKETS_INFO_FILE_PATH, &count) < 0 ? 1 : count;
+}
diff --git a/tools/perf/tests/expr.c b/tools/perf/tests/expr.c
index ea10fc4412c4..516504cf0ea5 100644
--- a/tools/perf/tests/expr.c
+++ b/tools/perf/tests/expr.c
@@ -10,7 +10,7 @@ static int test(struct expr_parse_ctx *ctx, const char *e, double val2)
 {
 	double val;
 
-	if (expr__parse(&val, ctx, e))
+	if (expr__parse(&val, ctx, e, 1))
 		TEST_ASSERT_VAL("parse test failed", 0);
 	TEST_ASSERT_VAL("unexpected value", val == val2);
 	return 0;
@@ -44,15 +44,15 @@ int test__expr(struct test *t __maybe_unused, int subtest __maybe_unused)
 		return ret;
 
 	p = "FOO/0";
-	ret = expr__parse(&val, &ctx, p);
+	ret = expr__parse(&val, &ctx, p, 1);
 	TEST_ASSERT_VAL("division by zero", ret == -1);
 
 	p = "BAR/";
-	ret = expr__parse(&val, &ctx, p);
+	ret = expr__parse(&val, &ctx, p, 1);
 	TEST_ASSERT_VAL("missing operand", ret == -1);
 
 	TEST_ASSERT_VAL("find other",
-			expr__find_other("FOO + BAR + BAZ + BOZO", "FOO", &other, &num_other) == 0);
+			expr__find_other("FOO + BAR + BAZ + BOZO", "FOO", &other, &num_other, 1) == 0);
 	TEST_ASSERT_VAL("find other", num_other == 3);
 	TEST_ASSERT_VAL("find other", !strcmp(other[0], "BAR"));
 	TEST_ASSERT_VAL("find other", !strcmp(other[1], "BAZ"));
diff --git a/tools/perf/util/expr.c b/tools/perf/util/expr.c
index c3382d58cf40..b228b737a5b0 100644
--- a/tools/perf/util/expr.c
+++ b/tools/perf/util/expr.c
@@ -27,10 +27,11 @@ void expr__ctx_init(struct expr_parse_ctx *ctx)
 
 static int
 __expr__parse(double *val, struct expr_parse_ctx *ctx, const char *expr,
-	      int start)
+	      int start, int param)
 {
 	struct expr_scanner_ctx scanner_ctx = {
 		.start_token = start,
+		.expr__runtimeparam = param,
 	};
 	YY_BUFFER_STATE buffer;
 	void *scanner;
@@ -54,9 +55,9 @@ __expr__parse(double *val, struct expr_parse_ctx *ctx, const char *expr,
 	return ret;
 }
 
-int expr__parse(double *final_val, struct expr_parse_ctx *ctx, const char *expr)
+int expr__parse(double *final_val, struct expr_parse_ctx *ctx, const char *expr, int param)
 {
-	return __expr__parse(final_val, ctx, expr, EXPR_PARSE) ? -1 : 0;
+	return __expr__parse(final_val, ctx, expr, EXPR_PARSE, param) ? -1 : 0;
 }
 
 static bool
@@ -74,13 +75,13 @@ already_seen(const char *val, const char *one, const char **other,
 }
 
 int expr__find_other(const char *expr, const char *one, const char ***other,
-		     int *num_other)
+		     int *num_other, int param)
 {
 	int err, i = 0, j = 0;
 	struct expr_parse_ctx ctx;
 
 	expr__ctx_init(&ctx);
-	err = __expr__parse(NULL, &ctx, expr, EXPR_OTHER);
+	err = __expr__parse(NULL, &ctx, expr, EXPR_OTHER, param);
 	if (err)
 		return -1;
 
diff --git a/tools/perf/util/expr.h b/tools/perf/util/expr.h
index 0938ad166ece..7786829b048b 100644
--- a/tools/perf/util/expr.h
+++ b/tools/perf/util/expr.h
@@ -17,12 +17,13 @@ struct expr_parse_ctx {
 
 struct expr_scanner_ctx {
 	int start_token;
+	int expr__runtimeparam;
 };
 
 void expr__ctx_init(struct expr_parse_ctx *ctx);
 void expr__add_id(struct expr_parse_ctx *ctx, const char *id, double val);
-int expr__parse(double *final_val, struct expr_parse_ctx *ctx, const char *expr);
+int expr__parse(double *final_val, struct expr_parse_ctx *ctx, const char *expr, int param);
 int expr__find_other(const char *expr, const char *one, const char ***other,
-		int *num_other);
+		int *num_other, int param);
 
 #endif
diff --git a/tools/perf/util/expr.l b/tools/perf/util/expr.l
index 2582c2464938..bde1e4543829 100644
--- a/tools/perf/util/expr.l
+++ b/tools/perf/util/expr.l
@@ -35,7 +35,7 @@ static int value(yyscan_t scanner, int base)
  * Allow @ instead of / to be able to specify pmu/event/ without
  * conflicts with normal division.
  */
-static char *normalize(char *str)
+static char *normalize(char *str, int expr__runtimeparam)
 {
 	char *ret = str;
 	char *dst = str;
@@ -45,6 +45,19 @@ static char *normalize(char *str)
 			*dst++ = '/';
 		else if (*str == '\\')
 			*dst++ = *++str;
+		 else if (*str == '?') {
+			char *paramval;
+			int i = 0;
+			int size = asprintf(&paramval, "%d", expr__runtimeparam);
+
+			if (size < 0)
+				*dst++ = '0';
+			else {
+				while (i < size)
+					*dst++ = paramval[i++];
+				free(paramval);
+			}
+		}
 		else
 			*dst++ = *str;
 		str++;
@@ -54,16 +67,16 @@ static char *normalize(char *str)
 	return ret;
 }
 
-static int str(yyscan_t scanner, int token)
+static int str(yyscan_t scanner, int token, int expr__runtimeparam)
 {
 	YYSTYPE *yylval = expr_get_lval(scanner);
 	char *text = expr_get_text(scanner);
 
-	yylval->str = normalize(strdup(text));
+	yylval->str = normalize(strdup(text), expr__runtimeparam);
 	if (!yylval->str)
 		return EXPR_ERROR;
 
-	yylval->str = normalize(yylval->str);
+	yylval->str = normalize(yylval->str, expr__runtimeparam);
 	return token;
 }
 %}
@@ -72,8 +85,8 @@ number		[0-9]+
 
 sch		[-,=]
 spec		\\{sch}
-sym		[0-9a-zA-Z_\.:@]+
-symbol		{spec}*{sym}*{spec}*{sym}*
+sym		[0-9a-zA-Z_\.:@?]+
+symbol		{spec}*{sym}*{spec}*{sym}*{spec}*{sym}
 
 %%
 	struct expr_scanner_ctx *sctx = expr_get_extra(yyscanner);
@@ -93,7 +106,7 @@ if		{ return IF; }
 else		{ return ELSE; }
 #smt_on		{ return SMT_ON; }
 {number}	{ return value(yyscanner, 10); }
-{symbol}	{ return str(yyscanner, ID); }
+{symbol}	{ return str(yyscanner, ID, sctx->expr__runtimeparam); }
 "|"		{ return '|'; }
 "^"		{ return '^'; }
 "&"		{ return '&'; }
diff --git a/tools/perf/util/metricgroup.c b/tools/perf/util/metricgroup.c
index b4919bcfbd8b..ec1742b63f44 100644
--- a/tools/perf/util/metricgroup.c
+++ b/tools/perf/util/metricgroup.c
@@ -474,6 +474,66 @@ static bool metricgroup__has_constraint(struct pmu_event *pe)
 	return false;
 }
 
+int __weak arch_get_runtimeparam(void)
+{
+	return 1;
+}
+
+static int metricgroup__add_metric_runtime_param(struct strbuf *events,
+			struct list_head *group_list, struct pmu_event *pe)
+{
+	int i, count;
+	int ret = -EINVAL;
+
+	count = arch_get_runtimeparam();
+
+	/* This loop is added to create multiple
+	 * events depend on count value and add
+	 * those events to group_list.
+	 */
+
+	for (i = 0; i < count; i++) {
+		const char **ids;
+		int idnum;
+		struct egroup *eg;
+		char value[PATH_MAX];
+
+		if (expr__find_other(pe->metric_expr, NULL, &ids, &idnum, i) < 0)
+			return ret;
+
+		if (events->len > 0)
+			strbuf_addf(events, ",");
+
+		if (metricgroup__has_constraint(pe))
+			metricgroup__add_metric_non_group(events, ids, idnum);
+		else
+			metricgroup__add_metric_weak_group(events, ids, idnum);
+
+		eg = malloc(sizeof(*eg));
+		if (!eg) {
+			ret = -ENOMEM;
+			return ret;
+		}
+
+		sprintf(value, "%s%c%d", pe->metric_name, '_', i);
+		eg->ids = ids;
+		eg->idnum = idnum;
+		eg->metric_name = strdup(value);
+		if (!eg->metric_name) {
+			ret = -ENOMEM;
+			return ret;
+		}
+
+		eg->metric_expr = pe->metric_expr;
+		eg->metric_unit = pe->unit;
+		list_add_tail(&eg->nd, group_list);
+		ret = 0;
+
+		if (ret != 0)
+			break;
+	}
+	return ret;
+}
 static int metricgroup__add_metric_param(struct strbuf *events,
 			struct list_head *group_list, struct pmu_event *pe)
 {
@@ -531,7 +591,11 @@ static int metricgroup__add_metric(const char *metric, struct strbuf *events,
 
 			pr_debug("metric expr %s for %s\n", pe->metric_expr, pe->metric_name);
 
-			ret = metricgroup__add_metric_param(events,
+			if (strstr(pe->metric_expr, "?"))
+				ret = metricgroup__add_metric_runtime_param(events,
+							group_list, pe);
+			else
+				ret = metricgroup__add_metric_param(events,
 							group_list, pe);
 			if (ret == -EINVAL)
 				continue;
diff --git a/tools/perf/util/metricgroup.h b/tools/perf/util/metricgroup.h
index 475c7f912864..81224ba1270d 100644
--- a/tools/perf/util/metricgroup.h
+++ b/tools/perf/util/metricgroup.h
@@ -34,4 +34,5 @@ int metricgroup__parse_groups(const struct option *opt,
 void metricgroup__print(bool metrics, bool groups, char *filter,
 			bool raw, bool details);
 bool metricgroup__has_metric(const char *metric);
+int arch_get_runtimeparam(void);
 #endif
diff --git a/tools/perf/util/stat-shadow.c b/tools/perf/util/stat-shadow.c
index 402af3e8d287..85ac6d913782 100644
--- a/tools/perf/util/stat-shadow.c
+++ b/tools/perf/util/stat-shadow.c
@@ -336,7 +336,7 @@ void perf_stat__collect_metric_expr(struct evlist *evsel_list)
 		metric_events = counter->metric_events;
 		if (!metric_events) {
 			if (expr__find_other(counter->metric_expr, counter->name,
-						&metric_names, &num_metric_names) < 0)
+						&metric_names, &num_metric_names, 1) < 0)
 				continue;
 
 			metric_events = calloc(sizeof(struct evsel *),
@@ -777,7 +777,15 @@ static void generic_metric(struct perf_stat_config *config,
 	}
 
 	if (!metric_events[i]) {
-		if (expr__parse(&ratio, &pctx, metric_expr) == 0) {
+		int param = 1;
+		if (strstr(metric_expr, "?")) {
+			char *tmp = strrchr(metric_name, '_');
+
+			tmp++;
+			param = strtol(tmp, &tmp, 10);
+		}
+
+		if (expr__parse(&ratio, &pctx, metric_expr, param) == 0) {
 			char *unit;
 			char metric_bf[64];
 
-- 
2.18.1