[PATCH 04/30] perf tools: Add comm string into struct thread_map

Jiri Olsa
2015-06-14T08:20:31Z

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

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

Link: http://lkml.kernel.org/n/tip-pf6bgmbujukce0sgliuhj2f4@git.kernel.org
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
---
tools/perf/util/python-ext-sources | 1 +
tools/perf/util/thread_map.c | 63 +++++++++++++++++++++++++++++++++++---
tools/perf/util/thread_map.h | 2 ++
3 files changed, 62 insertions(+), 4 deletions(-)

diff --git a/tools/perf/util/python-ext-sources b/tools/perf/util/python-ext-sources
index 4d28624a1eca..55ba8968a263 100644
--- a/tools/perf/util/python-ext-sources
+++ b/tools/perf/util/python-ext-sources
@@ -19,3 +19,4 @@ util/rblist.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 7f03f9facfdd..f7a49a693d27 100644
--- a/tools/perf/util/thread_map.c
+++ b/tools/perf/util/thread_map.c
@@ -8,8 +8,10 @@
#include <unistd.h>
#include "strlist.h"
#include <string.h>
+#include <api/fs/fs.h>
#include "thread_map.h"
#include "util.h"
+#include "debug.h"

/* Skip "." and ".." directories */
static int filter(const struct dirent *dir)
@@ -29,6 +31,44 @@ static struct thread_map *thread_map__realloc(struct thread_map *map, int nr)

#define thread_map__alloc(__nr) thread_map__realloc(NULL, __nr)

+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)
+ rtrim(*comm);
+
+ free(path);
+ return err;
+}
+
+static void comm_init(struct thread_map *map, int i)
+{
+ struct thread_map_data *data = &map->map[i];
+
+ /*
+ * The comm name is like extra bonus ;-),
+ * so just warn if we fail for any reason.
+ */
+ data->comm = NULL;
+
+ /* dummy pid comm initialization */
+ if (data->pid == -1) {
+ data->comm = strdup("dummy");
+ return;
+ }
+
+ /* try to get pid's comm string */
+ if (get_comm(&data->comm, data->pid))
+ pr_warning("Couldn't resolve comm name for pid %d\n", data->pid);
+}
+
struct thread_map *thread_map__new_by_pid(pid_t pid)
{
struct thread_map *threads;
@@ -44,8 +84,10 @@ struct thread_map *thread_map__new_by_pid(pid_t pid)

threads = thread_map__alloc(items);
if (threads != NULL) {
- for (i = 0; i < items; i++)
+ for (i = 0; i < items; i++) {
thread_map__pid(threads, i) = atoi(namelist[i]->d_name);
+ comm_init(threads, i);
+ }
threads->nr = items;
}

@@ -63,6 +105,7 @@ struct thread_map *thread_map__new_by_tid(pid_t tid)
if (threads != NULL) {
thread_map__pid(threads, 0) = tid;
threads->nr = 1;
+ comm_init(threads, 0);
}

return threads;
@@ -123,8 +166,10 @@ struct thread_map *thread_map__new_by_uid(uid_t uid)
threads = tmp;
}

- for (i = 0; i < items; i++)
+ for (i = 0; i < items; i++) {
thread_map__pid(threads, threads->nr + i) = atoi(namelist[i]->d_name);
+ comm_init(threads, threads->nr + i);
+ }

for (i = 0; i < items; i++)
zfree(&namelist[i]);
@@ -200,8 +245,9 @@ static struct thread_map *thread_map__new_by_pid_str(const char *pid_str)

threads = nt;

- for (i = 0; i < items; i++) {
- thread_map__pid(threads, j++) = atoi(namelist[i]->d_name);
+ for (i = 0; i < items; i++, j++) {
+ thread_map__pid(threads, j) = atoi(namelist[i]->d_name);
+ comm_init(threads, j);
zfree(&namelist[i]);
}
threads->nr = total_tasks;
@@ -229,6 +275,7 @@ struct thread_map *thread_map__new_dummy(void)
if (threads != NULL) {
thread_map__pid(threads, 0) = -1;
threads->nr = 1;
+ comm_init(threads, 0);
}
return threads;
}
@@ -269,6 +316,7 @@ static struct thread_map *thread_map__new_by_tid_str(const char *tid_str)
threads = nt;
thread_map__pid(threads, ntasks - 1) = tid;
threads->nr = ntasks;
+ comm_init(threads, ntasks - 1);
}
out:
return threads;
@@ -292,6 +340,13 @@ struct thread_map *thread_map__new_str(const char *pid, const char *tid,

void thread_map__delete(struct thread_map *threads)
{
+ int i;
+
+ if (threads) {
+ for (i = 0; i < threads->nr; i++)
+ free(thread_map__comm(threads, i));
+ }
+
free(threads);
}

diff --git a/tools/perf/util/thread_map.h b/tools/perf/util/thread_map.h
index 9377850c7b71..6933f9d316d9 100644
--- a/tools/perf/util/thread_map.h
+++ b/tools/perf/util/thread_map.h
@@ -6,6 +6,7 @@

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

struct thread_map {
@@ -14,6 +15,7 @@ struct thread_map {
};

#define thread_map__pid(__m, __t) __m->map[__t].pid
+#define thread_map__comm(__m, __t) __m->map[__t].comm

struct thread_map *thread_map__new_dummy(void);
struct thread_map *thread_map__new_by_pid(pid_t pid);
--
1.9.3