| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Date: Fri, 1 Dec 2017 11:44:25 -0300
From: Arnaldo Carvalho de Melo <acme@...nel.org>
To: Jin Yao <yao.jin@...ux.intel.com>
Cc: jolsa@...nel.org, peterz@...radead.org, mingo@...hat.com,
alexander.shishkin@...ux.intel.com, Linux-kernel@...r.kernel.org,
ak@...ux.intel.com, kan.liang@...el.com, yao.jin@...el.com
Subject: Re: [PATCH v5 10/12] perf util: Reuse thread_map__new_by_uid to
enumerate threads from /proc
Em Fri, Dec 01, 2017 at 06:57:34PM +0800, Jin Yao escreveu:
> Perf already has a function thread_map__new_by_uid() which can
> enumerate all threads from /proc by uid.
>
> This patch creates a static function enumerate_threads() which
> reuses the common code in thread_map__new_by_uid() to enumerate
> threads from /proc.
>
> The enumerate_threads() is shared by thread_map__new_by_uid()
> and a new function thread_map__new_threads().
>
> The new function thread_map__new_threads() is called to enumerate
> all threads from /proc.
>
> Signed-off-by: Jin Yao <yao.jin@...ux.intel.com>
> ---
> tools/perf/tests/thread-map.c | 2 +-
> tools/perf/util/evlist.c | 3 ++-
> tools/perf/util/thread_map.c | 19 ++++++++++++++++---
> tools/perf/util/thread_map.h | 3 ++-
> 4 files changed, 21 insertions(+), 6 deletions(-)
>
> diff --git a/tools/perf/tests/thread-map.c b/tools/perf/tests/thread-map.c
> index dbcb6a1..4de1939 100644
> --- a/tools/perf/tests/thread-map.c
> +++ b/tools/perf/tests/thread-map.c
> @@ -105,7 +105,7 @@ int test__thread_map_remove(struct test *test __maybe_unused, int subtest __mayb
> TEST_ASSERT_VAL("failed to allocate map string",
> asprintf(&str, "%d,%d", getpid(), getppid()) >= 0);
>
> - threads = thread_map__new_str(str, NULL, 0);
> + threads = thread_map__new_str(str, NULL, 0, false);
>
> TEST_ASSERT_VAL("failed to allocate thread_map",
> threads);
> diff --git a/tools/perf/util/evlist.c b/tools/perf/util/evlist.c
> index 199bb82..05b8f2b 100644
> --- a/tools/perf/util/evlist.c
> +++ b/tools/perf/util/evlist.c
> @@ -1102,7 +1102,8 @@ int perf_evlist__create_maps(struct perf_evlist *evlist, struct target *target)
> struct cpu_map *cpus;
> struct thread_map *threads;
>
> - threads = thread_map__new_str(target->pid, target->tid, target->uid);
> + threads = thread_map__new_str(target->pid, target->tid, target->uid,
> + target->per_thread);
>
> if (!threads)
> return -1;
> diff --git a/tools/perf/util/thread_map.c b/tools/perf/util/thread_map.c
> index be0d5a7..5672268 100644
> --- a/tools/perf/util/thread_map.c
> +++ b/tools/perf/util/thread_map.c
> @@ -92,7 +92,7 @@ struct thread_map *thread_map__new_by_tid(pid_t tid)
> return threads;
> }
>
> -struct thread_map *thread_map__new_by_uid(uid_t uid)
> +static struct thread_map *enumerate_threads(uid_t uid)
> {
> DIR *proc;
> int max_threads = 32, items, i;
> @@ -124,7 +124,7 @@ struct thread_map *thread_map__new_by_uid(uid_t uid)
> if (stat(path, &st) != 0)
> continue;
Look, for the case where you want all threads enumerated you will incur
the above stat() cost for all of them and will not use it at all...
And new_threads() seems vague, I'm using the ter used by 'perf record'
for system wide sampling, see the patch below:
diff --git a/tools/perf/util/thread_map.c b/tools/perf/util/thread_map.c
index be0d5a736dea..79d11bd4543a 100644
--- a/tools/perf/util/thread_map.c
+++ b/tools/perf/util/thread_map.c
@@ -92,7 +92,7 @@ struct thread_map *thread_map__new_by_tid(pid_t tid)
return threads;
}
-struct thread_map *thread_map__new_by_uid(uid_t uid)
+static struct thread_map *__thread_map__new_all_cpus(uid_t uid)
{
DIR *proc;
int max_threads = 32, items, i;
@@ -113,7 +113,6 @@ struct thread_map *thread_map__new_by_uid(uid_t uid)
while ((dirent = readdir(proc)) != NULL) {
char *end;
bool grow = false;
- struct stat st;
pid_t pid = strtol(dirent->d_name, &end, 10);
if (*end) /* only interested in proper numerical dirents */
@@ -121,11 +120,12 @@ struct thread_map *thread_map__new_by_uid(uid_t uid)
snprintf(path, sizeof(path), "/proc/%s", dirent->d_name);
- if (stat(path, &st) != 0)
- continue;
+ if (uid != UID_MAX) {
+ struct stat st;
- if (st.st_uid != uid)
- continue;
+ if (stat(path, &st) != 0 || st.st_uid != uid)
+ continue;
+ }
snprintf(path, sizeof(path), "/proc/%d/task", pid);
items = scandir(path, &namelist, filter, NULL);
@@ -178,6 +178,16 @@ struct thread_map *thread_map__new_by_uid(uid_t uid)
goto out_closedir;
}
+struct thread_map *thread_map__new_all_cpus(void)
+{
+ return __thread__new_all_cpus(UID_MAX);
+}
+
+struct thread_map *thread_map__new_by_uid(uid_t uid)
+{
+ return __thread__new_all_cpus(uid);
+}
+
struct thread_map *thread_map__new(pid_t pid, pid_t tid, uid_t uid)
{
if (pid != -1)
diff --git a/tools/perf/util/thread_map.h b/tools/perf/util/thread_map.h
index f15803985435..07a765fb22bb 100644
--- a/tools/perf/util/thread_map.h
+++ b/tools/perf/util/thread_map.h
@@ -23,6 +23,7 @@ struct thread_map *thread_map__new_dummy(void);
struct thread_map *thread_map__new_by_pid(pid_t pid);
struct thread_map *thread_map__new_by_tid(pid_t tid);
struct thread_map *thread_map__new_by_uid(uid_t uid);
+struct thread_map *thread_map__new_all_cpus(void);
struct thread_map *thread_map__new(pid_t pid, pid_t tid, uid_t uid);
struct thread_map *thread_map__new_event(struct thread_map_event *event);
Powered by blists - more mailing lists