Subject: [PATCH v3 6/8] perf/tools: Enhance JSON/metric infrastructure to handle "?"

From: Kajol Jain <[email-masked]>
Date: Sat, 29 Feb 2020 14:43:54 +0530

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', 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 <[email-masked]>
---
 tools/perf/arch/powerpc/util/header.c |  47 +++++++++++
 tools/perf/util/expr.h                |   1 +
 tools/perf/util/expr.l                |  18 ++++-
 tools/perf/util/expr.y                |   2 +
 tools/perf/util/metricgroup.c         | 112 ++++++++++++++++----------
 tools/perf/util/metricgroup.h         |   1 +
 tools/perf/util/stat-shadow.c         |   6 ++
 7 files changed, 144 insertions(+), 43 deletions(-)

diff --git a/tools/perf/arch/powerpc/util/header.c b/tools/perf/arch/powerpc/util/header.c
index 3b4cdfc5efd6..5c15589522fd 100644
--- a/tools/perf/arch/powerpc/util/header.c
+++ b/tools/perf/arch/powerpc/util/header.c
@@ -7,6 +7,11 @@
 #include <string.h>
 #include <linux/stringify.h>
 #include "header.h"
+#include "metricgroup.h"
+#include "evlist.h"
+#include <dirent.h>
+#include "pmu.h"
+#include <api/fs/fs.h>
 
 #define mfspr(rn)       ({unsigned long rval; \
 			 asm volatile("mfspr %0," __stringify(rn) \
@@ -16,6 +21,8 @@
 #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/"
+
 int
 get_cpuid(char *buffer, size_t sz)
 {
@@ -44,3 +51,43 @@ get_cpuid_str(struct perf_pmu *pmu __maybe_unused)
 
 	return bufp;
 }
+
+int arch_get_runtimeparam(void)
+{
+	int count = 0;
+	DIR *dir;
+	char path[PATH_MAX];
+	const char *sysfs = sysfs__mountpoint();
+	char filename[] = "sockets";
+	FILE *file;
+	char buf[16], *num;
+	int data;
+
+	if (!sysfs)
+		goto out;
+
+	snprintf(path, PATH_MAX,
+		 "%s" SOCKETS_INFO_FILE_PATH, sysfs);
+	dir = opendir(path);
+
+	if (!dir)
+		goto out;
+
+	strcat(path, filename);
+	file = fopen(path, "r");
+
+	if (!file)
+		goto out;
+
+	data = fread(buf, 1, sizeof(buf), file);
+
+	if (data == 0)
+		goto out;
+
+	count = strtol(buf, &num, 10);
+out:
+	if (!count)
+		count = 1;
+
+	return count;
+}
diff --git a/tools/perf/util/expr.h b/tools/perf/util/expr.h
index 28a0a2dfbd8c..7f7c902bff46 100644
--- a/tools/perf/util/expr.h
+++ b/tools/perf/util/expr.h
@@ -15,6 +15,7 @@ struct parse_ctx {
 	struct parse_id ids[MAX_PARSE_ID];
 };
 
+int expr__runtimeparam;
 void expr__ctx_init(struct parse_ctx *ctx);
 void expr__add_id(struct parse_ctx *ctx, const char *id, double val);
 int expr__parse(double *final_val, struct parse_ctx *ctx, const char *expr);
diff --git a/tools/perf/util/expr.l b/tools/perf/util/expr.l
index 1928f2a3dddc..2cc6fa4b1960 100644
--- a/tools/perf/util/expr.l
+++ b/tools/perf/util/expr.l
@@ -45,6 +45,20 @@ static char *normalize(char *str)
 			*dst++ = '/';
 		else if (*str == '\\')
 			*dst++ = *++str;
+		else if (*str == '?') {
+			int size = snprintf(NULL, 0, "%d", expr__runtimeparam);
+			char * paramval = (char *)malloc(size);
+			int i = 0;
+
+			if(!paramval)
+				*dst++ = '0';
+			else {
+				sprintf(paramval, "%d", expr__runtimeparam);
+				while(i < size)
+					*dst++ = paramval[i++];
+				free(paramval);
+			}
+		}
 		else
 			*dst++ = *str;
 		str++;
@@ -72,8 +86,8 @@ 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}
 
 %%
 	{
diff --git a/tools/perf/util/expr.y b/tools/perf/util/expr.y
index 4720cbe79357..0f3ef0f37bf4 100644
--- a/tools/perf/util/expr.y
+++ b/tools/perf/util/expr.y
@@ -38,6 +38,8 @@
 %type <num> expr if_expr
 
 %{
+int expr__runtimeparam;
+
 static void expr_error(double *final_val __maybe_unused,
 		       struct parse_ctx *ctx __maybe_unused,
 		       void *scanner,
diff --git a/tools/perf/util/metricgroup.c b/tools/perf/util/metricgroup.c
index 02aee946b6c1..f629828cc0de 100644
--- a/tools/perf/util/metricgroup.c
+++ b/tools/perf/util/metricgroup.c
@@ -399,6 +399,11 @@ void metricgroup__print(bool metrics, bool metricgroups, char *filter,
 	strlist__delete(metriclist);
 }
 
+int __weak arch_get_runtimeparam(void)
+{
+	return 1;
+}
+
 static int metricgroup__add_metric(const char *metric, struct strbuf *events,
 				   struct list_head *group_list)
 {
@@ -419,52 +424,77 @@ static int metricgroup__add_metric(const char *metric, struct strbuf *events,
 			continue;
 		if (match_metric(pe->metric_group, metric) ||
 		    match_metric(pe->metric_name, metric)) {
-			const char **ids;
-			int idnum;
-			struct egroup *eg;
-			bool no_group = false;
+			int k, count;
+
+			if (strstr(pe->metric_expr, "?"))
+				count = arch_get_runtimeparam();
+			else
+				count = 1;
+
+			/* This loop is added to create multiple
+			 * events depend on count value and add
+			 * those events to group_list.
+			 */
+			for (k = 0; k < count; k++) {
+				const char **ids;
+				int idnum;
+				struct egroup *eg;
+				bool no_group = false;
+				char value[PATH_MAX];
+
+				pr_debug("metric expr %s for %s\n",
+					 pe->metric_expr, pe->metric_name);
+				expr__runtimeparam = k;
+				if (expr__find_other(pe->metric_expr, NULL,
+						     &ids, &idnum) < 0)
+					continue;
+				if (events->len > 0)
+					strbuf_addf(events, ",");
+				for (j = 0; j < idnum; j++) {
+					pr_debug("found event %s\n", ids[j]);
+					/*
+					 * Duration time maps to a software
+					 * event and can make groups not count.
+					 * Always use it outside a group.
+					 */
+					if (!strcmp(ids[j], "duration_time")) {
+						if (j > 0)
+							strbuf_addf(events,
+								    "}:W,");
+						strbuf_addf(events,
+							    "duration_time");
+						no_group = true;
+						continue;
+					}
+					strbuf_addf(events, "%s%s",
+						    j == 0 || no_group ? "{" :
+						    ",", ids[j]);
+					no_group = false;
+				}
+				if (!no_group)
+					strbuf_addf(events, "}:W");
 
-			pr_debug("metric expr %s for %s\n", pe->metric_expr, pe->metric_name);
+				eg = malloc(sizeof(struct egroup));
+				if (!eg) {
+					ret = -ENOMEM;
+					break;
+				}
+				eg->ids = ids;
+				eg->idnum = idnum;
 
-			if (expr__find_other(pe->metric_expr,
-					     NULL, &ids, &idnum) < 0)
-				continue;
-			if (events->len > 0)
-				strbuf_addf(events, ",");
-			for (j = 0; j < idnum; j++) {
-				pr_debug("found event %s\n", ids[j]);
-				/*
-				 * Duration time maps to a software event and can make
-				 * groups not count. Always use it outside a
-				 * group.
-				 */
-				if (!strcmp(ids[j], "duration_time")) {
-					if (j > 0)
-						strbuf_addf(events, "}:W,");
-					strbuf_addf(events, "duration_time");
-					no_group = true;
-					continue;
+				if (strstr(pe->metric_expr, "?")) {
+					sprintf(value, "%s%c%d",
+						pe->metric_name, '_', k);
+				} else {
+					strcpy(value, pe->metric_name);
 				}
-				strbuf_addf(events, "%s%s",
-					j == 0 || no_group ? "{" : ",",
-					ids[j]);
-				no_group = false;
-			}
-			if (!no_group)
-				strbuf_addf(events, "}:W");
 
-			eg = malloc(sizeof(struct egroup));
-			if (!eg) {
-				ret = -ENOMEM;
-				break;
+				eg->metric_name = strdup(value);
+				eg->metric_expr = pe->metric_expr;
+				eg->metric_unit = pe->unit;
+				list_add_tail(&eg->nd, group_list);
+				ret = 0;
 			}
-			eg->ids = ids;
-			eg->idnum = idnum;
-			eg->metric_name = pe->metric_name;
-			eg->metric_expr = pe->metric_expr;
-			eg->metric_unit = pe->unit;
-			list_add_tail(&eg->nd, group_list);
-			ret = 0;
 		}
 	}
 	return ret;
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 0fd713d3674f..c1179f7d2b23 100644
--- a/tools/perf/util/stat-shadow.c
+++ b/tools/perf/util/stat-shadow.c
@@ -777,6 +777,12 @@ static void generic_metric(struct perf_stat_config *config,
 	}
 
 	if (!metric_events[i]) {
+		if (strstr(metric_expr, "?")) {
+			char *tmp = strrchr(metric_name, '_');
+
+			tmp++;
+			expr__runtimeparam = strtol(tmp, &tmp, 10);
+		}
 		if (expr__parse(&ratio, &pctx, metric_expr) == 0) {
 			char *unit;
 			char metric_bf[64];
-- 
2.21.0