[PATCH 1/5] perf,tools: introduce get_cpu_max_freq

[kan.liang@intel.com]

From: Kan Liang <kan.liang@intel.com>

Get cpu max frequency from the first online cpu, and save the MHz value
in get_cpu_max_freq.

Signed-off-by: Kan Liang <kan.liang@intel.com>
---
 tools/perf/builtin-report.c |  2 ++
 tools/perf/util/cpumap.c    | 32 ++++++++++++++++++++++++++++++++
 tools/perf/util/cpumap.h    |  2 ++
 3 files changed, 36 insertions(+)

diff --git a/tools/perf/builtin-report.c b/tools/perf/builtin-report.c
index 95a4771..62cce98 100644
--- a/tools/perf/builtin-report.c
+++ b/tools/perf/builtin-report.c
@@ -818,6 +818,8 @@ repeat:
 		symbol_conf.cumulate_callchain = false;
 	}
 
+	cpu_max_freq = get_cpu_max_freq() / 1000;
+
 	if (setup_sorting() < 0) {
 		if (sort_order)
 			parse_options_usage(report_usage, options, "s", 1);
diff --git a/tools/perf/util/cpumap.c b/tools/perf/util/cpumap.c
index 3667e21..548ef13 100644
--- a/tools/perf/util/cpumap.c
+++ b/tools/perf/util/cpumap.c
@@ -499,3 +499,35 @@ int cpu__setup_cpunode_map(void)
 	closedir(dir1);
 	return 0;
 }
+
+unsigned int get_cpu_max_freq(void)
+{
+	const char *mnt;
+	char path[PATH_MAX], tmp;
+	FILE *fp;
+	unsigned int freq;
+	int cpu = 0;
+	int ret;
+
+	mnt = sysfs__mountpoint();
+	if (!mnt)
+		return 0;
+
+	snprintf(path, PATH_MAX, "%s/devices/system/cpu/online", mnt);
+	fp = fopen(path, "r");
+	if (fp) {
+		ret = fscanf(fp, "%u%c", &cpu, &tmp);
+		fclose(fp);
+		if (ret < 1)
+			return 0;
+	}
+
+	snprintf(path, PATH_MAX, "%s/devices/system/cpu/cpu%d/cpufreq/cpuinfo_max_freq", mnt, cpu);
+	fp = fopen(path, "r");
+	if (!fp)
+		return 0;
+	ret = fscanf(fp, "%u", &freq);
+	fclose(fp);
+
+	return (ret == 1) ? freq : 0;
+}
diff --git a/tools/perf/util/cpumap.h b/tools/perf/util/cpumap.h
index 0af9cec..70ac686 100644
--- a/tools/perf/util/cpumap.h
+++ b/tools/perf/util/cpumap.h
@@ -56,8 +56,10 @@ static inline bool cpu_map__empty(const struct cpu_map *map)
 int max_cpu_num;
 int max_node_num;
 int *cpunode_map;
+unsigned int cpu_max_freq;
 
 int cpu__setup_cpunode_map(void);
+unsigned int get_cpu_max_freq(void);
 
 static inline int cpu__max_node(void)
 {
-- 
1.8.3.1