[tip:perf/urgent] perf thrad_map: Add comm string into array

tip-bot for Jiri Olsa
2015-06-30T04:53:15Z

Commit-ID: 792402fd5c0a5a5300868e9dfc8ee569f3a39169
Gitweb: http://git.kernel.org/tip/792402fd5c0a5a5300868e9dfc8ee569f3a39169
Author: Jiri Olsa <jolsa@kernel.org>
AuthorDate: Fri, 26 Jun 2015 11:29:07 +0200
Committer: Arnaldo Carvalho de Melo <acme@redhat.com>
CommitDate: Fri, 26 Jun 2015 11:07:01 -0300

perf thrad_map: Add comm string into array

Adding support to hold comm name together with pids in 'struct
thread_map'. It will be useful for --per-thread option to display task
pid together with task name.

Adding thread_map__read_comms function that reads/set
comm string for the 'struct thread_map'.

Getting the task name from /proc/$pid/comm.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/r/1435310967-14570-3-git-send-email-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
tools/perf/util/python-ext-sources | 1 +
tools/perf/util/thread_map.c | 59 ++++++++++++++++++++++++++++++++++++++
tools/perf/util/thread_map.h | 8 ++++++
3 files changed, 68 insertions(+)

diff --git a/tools/perf/util/python-ext-sources b/tools/perf/util/python-ext-sources
index 5925fec..e23ded4 100644
--- a/tools/perf/util/python-ext-sources
+++ b/tools/perf/util/python-ext-sources
@@ -20,3 +20,4 @@ util/stat.c
util/strlist.c
util/trace-event.c
../../lib/rbtree.c
+util/string.c
diff --git a/tools/perf/util/thread_map.c b/tools/perf/util/thread_map.c
index ed76c17..da7646d 100644
--- a/tools/perf/util/thread_map.c
+++ b/tools/perf/util/thread_map.c
@@ -8,9 +8,11 @@
#include <unistd.h>
#include "strlist.h"
#include <string.h>
+#include <api/fs/fs.h>
#include "asm/bug.h"
#include "thread_map.h"
#include "util.h"
+#include "debug.h"

/* Skip "." and ".." directories */
static int filter(const struct dirent *dir)
@@ -319,8 +321,12 @@ struct thread_map *thread_map__new_str(const char *pid, const char *tid,
static void thread_map__delete(struct thread_map *threads)
{
if (threads) {
+ int i;
+
WARN_ONCE(atomic_read(&threads->refcnt) != 0,
"thread map refcnt unbalanced\n");
+ for (i = 0; i < threads->nr; i++)
+ free(thread_map__comm(threads, i));
free(threads);
}
}
@@ -348,3 +354,56 @@ size_t thread_map__fprintf(struct thread_map *threads, FILE *fp)

return printed + fprintf(fp, "\n");
}
+
+static int get_comm(char **comm, pid_t pid)
+{
+ char *path;
+ size_t size;
+ int err;
+
+ if (asprintf(&path, "%s/%d/comm", procfs__mountpoint(), pid) == -1)
+ return -ENOMEM;
+
+ err = filename__read_str(path, comm, &size);
+ if (!err) {
+ /*
+ * We're reading 16 bytes, while filename__read_str
+ * allocates data per BUFSIZ bytes, so we can safely
+ * mark the end of the string.
+ */
+ (*comm)[size] = 0;
+ rtrim(*comm);
+ }
+
+ free(path);
+ return err;
+}
+
+static void comm_init(struct thread_map *map, int i)
+{
+ pid_t pid = thread_map__pid(map, i);
+ char *comm = NULL;
+
+ /* dummy pid comm initialization */
+ if (pid == -1) {
+ map->map[i].comm = strdup("dummy");
+ return;
+ }
+
+ /*
+ * The comm name is like extra bonus ;-),
+ * so just warn if we fail for any reason.
+ */
+ if (get_comm(&comm, pid))
+ pr_warning("Couldn't resolve comm name for pid %d\n", pid);
+
+ map->map[i].comm = comm;
+}
+
+void thread_map__read_comms(struct thread_map *threads)
+{
+ int i;
+
+ for (i = 0; i < threads->nr; ++i)
+ comm_init(threads, i);
+}
diff --git a/tools/perf/util/thread_map.h b/tools/perf/util/thread_map.h
index 6b0cd2d..af679d8 100644
--- a/tools/perf/util/thread_map.h
+++ b/tools/perf/util/thread_map.h
@@ -7,6 +7,7 @@

struct thread_map_data {
pid_t pid;
+ char *comm;
};

struct thread_map {
@@ -44,4 +45,11 @@ thread_map__set_pid(struct thread_map *map, int thread, pid_t pid)
{
map->map[thread].pid = pid;
}
+
+static inline char *thread_map__comm(struct thread_map *map, int thread)
+{
+ return map->map[thread].comm;
+}
+
+void thread_map__read_comms(struct thread_map *threads);
#endif /* __PERF_THREAD_MAP_H */