Re: [PATCH 02/27] perf tools: Add comm string into struct thread_map
From: Arnaldo Carvalho de Melo
Date: Tue Jun 23 2015 - 17:02:23 EST
Em Tue, Jun 23, 2015 at 12:36:03AM +0200, Jiri Olsa escreveu:
> 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.
>
> Getting the task name from /proc/$pid/comm.
Do we really need to read this all the time? Or just for tools that need
this?
Can't we have a thread_map__read_comms(map);
That we can make this specific --per-thread option in 'stat' call?
Applied the first patch after breaking it into two, one to add the
accessors and the other to transform the map entries into a struct.
Pushed to perf/core already.
- Arnaldo
> Link: http://lkml.kernel.org/n/tip-pf6bgmbujukce0sgliuhj2f4@xxxxxxxxxxxxxx
> Signed-off-by: Jiri Olsa <jolsa@xxxxxxxxxx>
> ---
> tools/perf/util/python-ext-sources | 1 +
> tools/perf/util/thread_map.c | 67 ++++++++++++++++++++++++++++++++++++--
> tools/perf/util/thread_map.h | 12 +++++++
> 3 files changed, 77 insertions(+), 3 deletions(-)
>
> diff --git a/tools/perf/util/python-ext-sources b/tools/perf/util/python-ext-sources
> index 5925fec90562..e23ded40c79e 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 7a4be3754d05..5b2f2495af26 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 +31,51 @@ 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) {
> + /*
> + * 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) {
> + thread_map__set_comm(map, i, 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);
> +
> + thread_map__set_comm(map, i, comm);
> +}
> +
> struct thread_map *thread_map__new_by_pid(pid_t pid)
> {
> struct thread_map *threads;
> @@ -44,8 +91,10 @@ 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__set_pid(threads, i, atoi(namelist[i]->d_name));
> + comm_init(threads, i);
> + }
> threads->nr = items;
> }
>
> @@ -63,6 +112,7 @@ struct thread_map *thread_map__new_by_tid(pid_t tid)
> if (threads != NULL) {
> thread_map__set_pid(threads, 0, tid);
> threads->nr = 1;
> + comm_init(threads, 0);
> }
>
> return threads;
> @@ -126,6 +176,7 @@ struct thread_map *thread_map__new_by_uid(uid_t uid)
> for (i = 0; i < items; i++) {
> thread_map__set_pid(threads, threads->nr + i,
> atoi(namelist[i]->d_name));
> + comm_init(threads, threads->nr + i);
> }
>
> for (i = 0; i < items; i++)
> @@ -202,8 +253,9 @@ static struct thread_map *thread_map__new_by_pid_str(const char *pid_str)
>
> threads = nt;
>
> - for (i = 0; i < items; i++) {
> - thread_map__set_pid(threads, j++, atoi(namelist[i]->d_name));
> + for (i = 0; i < items; i++, j++) {
> + thread_map__set_pid(threads, j, atoi(namelist[i]->d_name));
> + comm_init(threads, j);
> zfree(&namelist[i]);
> }
> threads->nr = total_tasks;
> @@ -231,6 +283,7 @@ struct thread_map *thread_map__new_dummy(void)
> if (threads != NULL) {
> thread_map__set_pid(threads, 0, -1);
> threads->nr = 1;
> + comm_init(threads, 0);
> }
> return threads;
> }
> @@ -271,6 +324,7 @@ static struct thread_map *thread_map__new_by_tid_str(const char *tid_str)
> threads = nt;
> thread_map__set_pid(threads, ntasks - 1, tid);
> threads->nr = ntasks;
> + comm_init(threads, ntasks - 1);
> }
> out:
> return threads;
> @@ -294,6 +348,13 @@ 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 b9f40679f589..0f67843475e6 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 {
> @@ -41,4 +42,15 @@ 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;
> +}
> +
> +static inline void
> +thread_map__set_comm(struct thread_map *map, int thread, char *comm)
> +{
> + map->map[thread].comm = comm;
> +}
> #endif /* __PERF_THREAD_MAP_H */
> --
> 1.9.3
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