[RFC PATCH 1/4] perf: Read cache instance ID when building cache topology

[K Prateek Nayak]

CPU cache level data currently stores cache level, type, line size,
associativity, sets, total cache size, and the CPUs sharing the cache.
Also read and store the cache instance ID from
"/sys/devices/system/cpu/cpuX/cache/indexY/id" in the cache level data.
Use instance ID as well when comparing cache levels.

Signed-off-by: K Prateek Nayak <kprateek.nayak@xxxxxxx>
---
 tools/perf/util/env.h    | 1 +
 tools/perf/util/header.c | 7 +++++++
 2 files changed, 8 insertions(+)

diff --git a/tools/perf/util/env.h b/tools/perf/util/env.h
index 4566c51f2fd9..d761bfae76af 100644
--- a/tools/perf/util/env.h
+++ b/tools/perf/util/env.h
@@ -17,6 +17,7 @@ struct cpu_topology_map {
 
 struct cpu_cache_level {
 	u32	level;
+	u32	id;
 	u32	line_size;
 	u32	sets;
 	u32	ways;
diff --git a/tools/perf/util/header.c b/tools/perf/util/header.c
index 404d816ca124..5c3f5d260612 100644
--- a/tools/perf/util/header.c
+++ b/tools/perf/util/header.c
@@ -1131,6 +1131,9 @@ static bool cpu_cache_level__cmp(struct cpu_cache_level *a, struct cpu_cache_lev
 	if (a->level != b->level)
 		return false;
 
+	if (a->id != b->id)
+		return false;
+
 	if (a->line_size != b->line_size)
 		return false;
 
@@ -1168,6 +1171,10 @@ static int cpu_cache_level__read(struct cpu_cache_level *cache, u32 cpu, u16 lev
 	if (sysfs__read_int(file, (int *) &cache->level))
 		return -1;
 
+	scnprintf(file, PATH_MAX, "%s/id", path);
+	if (sysfs__read_int(file, (int *) &cache->id))
+		return -1;
+
 	scnprintf(file, PATH_MAX, "%s/coherency_line_size", path);
 	if (sysfs__read_int(file, (int *) &cache->line_size))
 		return -1;
-- 
2.34.1