[PATCH 06/10] perf, tools: Automatically look for event file name for cpu

From: Andi Kleen
Date: Wed Jul 30 2014 - 19:23:42 EST


From: Andi Kleen <ak@xxxxxxxxxxxxxxx>

When no JSON event file is specified automatically look
for a suitable file in ~/.cache/pmu-events.

The event file format is per architecture, but can be
extended for other architectures.

v2: Supports XDG_CACHE_HOME and defaults to ~/.cache/pmu-events
v3: Minor updates and handle EVENTMAP.
v4: Unify with header.c. Now uses CPUID directly.
Acked-by: Namhyung Kim <namhyung@xxxxxxxxxx>
Signed-off-by: Andi Kleen <ak@xxxxxxxxxxxxxxx>
---
tools/perf/arch/x86/util/header.c | 19 ++++++++++++++++---
tools/perf/util/jevents.c | 40 +++++++++++++++++++++++++++++++++++++++
tools/perf/util/jevents.h | 1 +
tools/perf/util/pmu.c | 2 +-
4 files changed, 58 insertions(+), 4 deletions(-)

diff --git a/tools/perf/arch/x86/util/header.c b/tools/perf/arch/x86/util/header.c
index 146d12a..76e0ece 100644
--- a/tools/perf/arch/x86/util/header.c
+++ b/tools/perf/arch/x86/util/header.c
@@ -5,6 +5,7 @@
#include <string.h>

#include "../../util/header.h"
+#include "../../util/jevents.h"

static inline void
cpuid(unsigned int op, unsigned int *a, unsigned int *b, unsigned int *c,
@@ -19,8 +20,8 @@ cpuid(unsigned int op, unsigned int *a, unsigned int *b, unsigned int *c,
: "a" (op));
}

-int
-get_cpuid(char *buffer, size_t sz)
+static int
+__get_cpuid(char *buffer, size_t sz, const char *fmt)
{
unsigned int a, b, c, d, lvl;
int family = -1, model = -1, step = -1;
@@ -48,7 +49,7 @@ get_cpuid(char *buffer, size_t sz)
if (family >= 0x6)
model += ((a >> 16) & 0xf) << 4;
}
- nb = scnprintf(buffer, sz, "%s,%u,%u,%u$", vendor, family, model, step);
+ nb = scnprintf(buffer, sz, fmt, vendor, family, model, step);

/* look for end marker to ensure the entire data fit */
if (strchr(buffer, '$')) {
@@ -57,3 +58,15 @@ get_cpuid(char *buffer, size_t sz)
}
return -1;
}
+
+int get_cpuid(char *buffer, size_t sz)
+{
+ return __get_cpuid(buffer, sz, "%s,%u,%u,%u$");
+}
+
+char *get_cpu_str(void)
+{
+ char *buf = malloc(128);
+ __get_cpuid(buf, 128, "%s-%d-%X-core");
+ return buf;
+}
diff --git a/tools/perf/util/jevents.c b/tools/perf/util/jevents.c
index 023757c..ef4c047 100644
--- a/tools/perf/util/jevents.c
+++ b/tools/perf/util/jevents.c
@@ -39,6 +39,44 @@
#include "json.h"
#include "jevents.h"

+__attribute__((weak)) char *get_cpu_str(void)
+{
+ return NULL;
+}
+
+static const char *json_default_name(void)
+{
+ char *cache;
+ char *idstr = get_cpu_str();
+ char *res = NULL;
+ char *home = NULL;
+ char *emap;
+
+ emap = getenv("EVENTMAP");
+ if (emap) {
+ if (access(emap, R_OK) == 0)
+ return emap;
+ if (asprintf(&idstr, "%s-core", emap) < 0)
+ return NULL;
+ }
+
+ cache = getenv("XDG_CACHE_HOME");
+ if (!cache) {
+ home = getenv("HOME");
+ if (!home || asprintf(&cache, "%s/.cache", home) < 0)
+ goto out;
+ }
+ if (cache && idstr)
+ res = mkpath("%s/pmu-events/%s.json",
+ cache,
+ idstr);
+ if (home)
+ free(cache);
+out:
+ free(idstr);
+ return res;
+}
+
static void addfield(char *map, char **dst, const char *sep,
const char *a, jsmntok_t *bt)
{
@@ -171,6 +209,8 @@ int json_events(const char *fn,
int i, j, len;
char *map;

+ if (!fn)
+ fn = json_default_name();
tokens = parse_json(fn, &map, &size, &len);
if (!tokens)
return -EIO;
diff --git a/tools/perf/util/jevents.h b/tools/perf/util/jevents.h
index fbc4549..86a94dd 100644
--- a/tools/perf/util/jevents.h
+++ b/tools/perf/util/jevents.h
@@ -4,5 +4,6 @@
int json_events(const char *fn,
int (*func)(void *data, char *name, char *event, char *desc),
void *data);
+char *get_cpu_str(void);

#endif
diff --git a/tools/perf/util/pmu.c b/tools/perf/util/pmu.c
index 9f154af..fa21319 100644
--- a/tools/perf/util/pmu.c
+++ b/tools/perf/util/pmu.c
@@ -433,7 +433,7 @@ static struct perf_pmu *pmu_lookup(const char *name)
if (pmu_aliases(name, &aliases))
return NULL;

- if (!strcmp(name, "cpu") && json_file)
+ if (!strcmp(name, "cpu"))
json_events(json_file, add_alias, &aliases);

if (pmu_type(name, &type))
--
1.9.3

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