From: Ian Rogers <irogers@google.com>
To: irogers@google.com, acme@kernel.org, namhyung@kernel.org
Cc: adrian.hunter@intel.com, bvanassche@acm.org, elver@google.com,
james.clark@linaro.org, jolsa@kernel.org,
justinstitt@google.com, linux-kernel@vger.kernel.org,
linux-perf-users@vger.kernel.org, llvm@lists.linux.dev,
mingo@redhat.com, morbo@google.com, nathan@kernel.org,
ndesaulniers@google.com, peterz@infradead.org
Subject: [PATCH v13 16/21] perf intel-tpebs: Use DEFINE_MUTEX for tpebs_mtx and add lock annotations
Date: Fri, 13 Nov 2026 08:41:47 -0800 [thread overview]
Message-ID: <20261113164152.2095566-17-irogers@google.com> (raw)
In-Reply-To: <20261113164152.2095566-1-irogers@google.com>
Replace tpebs_mtx_get() and its pthread_once() initialization helper
tpebs_init() with DEFINE_MUTEX(tpebs_mtx) and static initializers for
control_fd and ack_fd, and add __guarded_by(&tpebs_mtx) and
__must_hold(&tpebs_mtx) annotations to the TPEBS state.
Signed-off-by: Ian Rogers <irogers@google.com>
---
tools/perf/util/intel-tpebs.c | 107 +++++++++++++++-------------------
1 file changed, 47 insertions(+), 60 deletions(-)
diff --git a/tools/perf/util/intel-tpebs.c b/tools/perf/util/intel-tpebs.c
index 5cb090b27fbd..d79d42a36a53 100644
--- a/tools/perf/util/intel-tpebs.c
+++ b/tools/perf/util/intel-tpebs.c
@@ -38,16 +38,17 @@
bool tpebs_recording;
enum tpebs_mode tpebs_mode;
-static LIST_HEAD(tpebs_results);
-static pthread_t tpebs_reader_thread;
-static struct child_process tpebs_cmd;
-static int control_fd[2], ack_fd[2];
-static struct mutex tpebs_mtx;
+static DEFINE_MUTEX(tpebs_mtx);
+static struct list_head tpebs_results __guarded_by(&tpebs_mtx) = LIST_HEAD_INIT(tpebs_results);
+static pthread_t tpebs_reader_thread __guarded_by(&tpebs_mtx);
+static struct child_process tpebs_cmd __guarded_by(&tpebs_mtx);
static struct cond tpebs_cmd_cond = { .cond = PTHREAD_COND_INITIALIZER };
-static bool tpebs_stopping;
-static bool tpebs_enabled;
-static bool tpebs_cmd_in_flight;
-static uint64_t tpebs_gen;
+static int control_fd[2] __guarded_by(&tpebs_mtx) = { -1, -1 };
+static int ack_fd[2] __guarded_by(&tpebs_mtx) = { -1, -1 };
+static bool tpebs_stopping __guarded_by(&tpebs_mtx);
+static bool tpebs_enabled __guarded_by(&tpebs_mtx);
+static bool tpebs_cmd_in_flight __guarded_by(&tpebs_mtx);
+static uint64_t tpebs_gen __guarded_by(&tpebs_mtx);
struct tpebs_retire_lat {
struct list_head nd;
@@ -63,25 +64,11 @@ struct tpebs_retire_lat {
bool started;
};
-static void tpebs_init(void)
-{
- mutex_init(&tpebs_mtx);
- control_fd[0] = control_fd[1] = -1;
- ack_fd[0] = ack_fd[1] = -1;
-}
-
-static struct mutex *tpebs_mtx_get(void)
-{
- static pthread_once_t tpebs_once = PTHREAD_ONCE_INIT;
-
- pthread_once(&tpebs_once, tpebs_init);
- return &tpebs_mtx;
-}
-
static struct tpebs_retire_lat *tpebs_retire_lat__find(struct evsel *evsel)
- __must_hold(tpebs_mtx_get());
+ __must_hold(&tpebs_mtx);
static int evsel__tpebs_start_perf_record(struct evsel *evsel)
+ __must_hold(&tpebs_mtx)
{
const char **record_argv;
int tpebs_event_size = 0, i = 0, ret;
@@ -209,19 +196,19 @@ static int process_sample_event(const struct perf_tool *tool __maybe_unused,
{
struct tpebs_retire_lat *t;
- mutex_lock(tpebs_mtx_get());
+ mutex_lock(&tpebs_mtx);
if (tpebs_stopping || tpebs_cmd.pid == 0) {
/* Record is stopping or has terminated. */
- mutex_unlock(tpebs_mtx_get());
+ mutex_unlock(&tpebs_mtx);
return 0;
}
t = tpebs_retire_lat__find(sample->evsel);
if (!t) {
- mutex_unlock(tpebs_mtx_get());
+ mutex_unlock(&tpebs_mtx);
return -EINVAL;
}
if (should_ignore_sample(sample, t)) {
- mutex_unlock(tpebs_mtx_get());
+ mutex_unlock(&tpebs_mtx);
return 0;
}
/*
@@ -231,7 +218,7 @@ static int process_sample_event(const struct perf_tool *tool __maybe_unused,
*/
t->last = sample->weight3;
update_stats(&t->stats, sample->weight3);
- mutex_unlock(tpebs_mtx_get());
+ mutex_unlock(&tpebs_mtx);
return 0;
}
@@ -261,7 +248,7 @@ static void *__sample_reader(void *arg)
return NULL;
}
-static int tpebs_send_record_cmd(const char *msg) __must_hold(tpebs_mtx_get())
+static int tpebs_send_record_cmd(const char *msg) __must_hold(&tpebs_mtx)
{
struct pollfd pollfd = { .events = POLLIN, };
bool is_stop = !strcmp(msg, EVLIST_CTL_CMD_STOP_TAG);
@@ -272,7 +259,7 @@ static int tpebs_send_record_cmd(const char *msg) __must_hold(tpebs_mtx_get())
while (tpebs_cmd_in_flight) {
if (!is_stop && tpebs_stopping)
return -EBUSY;
- cond_wait(&tpebs_cmd_cond, tpebs_mtx_get());
+ cond_wait(&tpebs_cmd_cond, &tpebs_mtx);
}
if (!is_stop && tpebs_stopping)
return -EBUSY;
@@ -289,7 +276,7 @@ static int tpebs_send_record_cmd(const char *msg) __must_hold(tpebs_mtx_get())
* Let go of the lock while sending/receiving as blocking can starve the
* sample reading thread.
*/
- mutex_unlock(tpebs_mtx_get());
+ mutex_unlock(&tpebs_mtx);
/* Send perf record command. */
len = scnprintf(cmd_buf, sizeof(cmd_buf), "%s\n", msg);
@@ -317,10 +304,10 @@ static int tpebs_send_record_cmd(const char *msg) __must_hold(tpebs_mtx_get())
if (!poll(&pollfd, 1, 500)) {
bool stopping, finished;
- mutex_lock(tpebs_mtx_get());
+ mutex_lock(&tpebs_mtx);
stopping = tpebs_stopping;
finished = !stopping && check_if_command_finished(&tpebs_cmd);
- mutex_unlock(tpebs_mtx_get());
+ mutex_unlock(&tpebs_mtx);
if (stopping) {
ret = -EBUSY;
goto out;
@@ -340,10 +327,10 @@ static int tpebs_send_record_cmd(const char *msg) __must_hold(tpebs_mtx_get())
if (!(pollfd.revents & POLLIN)) {
bool stopping, finished;
- mutex_lock(tpebs_mtx_get());
+ mutex_lock(&tpebs_mtx);
stopping = tpebs_stopping;
finished = !stopping && check_if_command_finished(&tpebs_cmd);
- mutex_unlock(tpebs_mtx_get());
+ mutex_unlock(&tpebs_mtx);
if (stopping) {
ret = -EBUSY;
goto out;
@@ -365,7 +352,7 @@ static int tpebs_send_record_cmd(const char *msg) __must_hold(tpebs_mtx_get())
pr_err("tpebs: perf record control ack failed\n");
out:
/* Re-take lock as expected by caller. */
- mutex_lock(tpebs_mtx_get());
+ mutex_lock(&tpebs_mtx);
tpebs_cmd_in_flight = false;
cond_broadcast(&tpebs_cmd_cond);
return ret;
@@ -374,7 +361,7 @@ static int tpebs_send_record_cmd(const char *msg) __must_hold(tpebs_mtx_get())
/*
* tpebs_stop - stop the sample data read thread and the perf record process.
*/
-static int tpebs_stop(void) __must_hold(tpebs_mtx_get())
+static int tpebs_stop(void) __must_hold(&tpebs_mtx)
{
int ret = 0;
@@ -399,9 +386,9 @@ static int tpebs_stop(void) __must_hold(tpebs_mtx_get())
*/
tpebs_cmd.pid = 0;
reader_thread = tpebs_reader_thread;
- mutex_unlock(tpebs_mtx_get());
+ mutex_unlock(&tpebs_mtx);
pthread_join(reader_thread, NULL);
- mutex_lock(tpebs_mtx_get());
+ mutex_lock(&tpebs_mtx);
if (control_fd[0] >= 0) {
close(control_fd[0]);
control_fd[0] = -1;
@@ -537,20 +524,20 @@ static int evsel__tpebs_prepare(struct evsel *evsel)
struct evsel *pos;
struct tpebs_retire_lat *tpebs_event;
- mutex_lock(tpebs_mtx_get());
+ mutex_lock(&tpebs_mtx);
tpebs_event = tpebs_retire_lat__find(evsel);
if (tpebs_event) {
/* evsel, or an identically named one, was already prepared. */
- mutex_unlock(tpebs_mtx_get());
+ mutex_unlock(&tpebs_mtx);
return 0;
}
tpebs_event = tpebs_retire_lat__new(evsel);
if (!tpebs_event) {
- mutex_unlock(tpebs_mtx_get());
+ mutex_unlock(&tpebs_mtx);
return -ENOMEM;
}
list_add_tail(&tpebs_event->nd, &tpebs_results);
- mutex_unlock(tpebs_mtx_get());
+ mutex_unlock(&tpebs_mtx);
/*
* Eagerly prepare all other evsels on the list to try to ensure that by
@@ -586,9 +573,9 @@ int evsel__tpebs_open(struct evsel *evsel)
if (!tpebs_recording)
return 0;
- mutex_lock(tpebs_mtx_get());
+ mutex_lock(&tpebs_mtx);
if (tpebs_stopping) {
- mutex_unlock(tpebs_mtx_get());
+ mutex_unlock(&tpebs_mtx);
return -EBUSY;
}
/* Only start the events once. */
@@ -598,17 +585,17 @@ int evsel__tpebs_open(struct evsel *evsel)
t = tpebs_retire_lat__find(evsel);
valid = t && t->started;
- mutex_unlock(tpebs_mtx_get());
+ mutex_unlock(&tpebs_mtx);
/* May fail as the event wasn't started. */
return valid ? 0 : -EBUSY;
}
- mutex_unlock(tpebs_mtx_get());
+ mutex_unlock(&tpebs_mtx);
ret = evsel__tpebs_prepare(evsel);
if (ret)
return ret;
- mutex_lock(tpebs_mtx_get());
+ mutex_lock(&tpebs_mtx);
if (tpebs_stopping || tpebs_cmd.pid != 0) {
ret = -EBUSY;
goto out;
@@ -671,14 +658,14 @@ int evsel__tpebs_open(struct evsel *evsel)
if (actual_pid > 0) {
kill(actual_pid, SIGTERM);
while (tpebs_cmd_in_flight)
- cond_wait(&tpebs_cmd_cond, tpebs_mtx_get());
+ cond_wait(&tpebs_cmd_cond, &tpebs_mtx);
tpebs_cmd.pid = 0;
if (started_thread) {
pthread_t reader_thread = tpebs_reader_thread;
- mutex_unlock(tpebs_mtx_get());
+ mutex_unlock(&tpebs_mtx);
pthread_join(reader_thread, NULL);
- mutex_lock(tpebs_mtx_get());
+ mutex_lock(&tpebs_mtx);
}
}
if (tpebs_cmd.out >= 0) {
@@ -709,7 +696,7 @@ int evsel__tpebs_open(struct evsel *evsel)
tpebs_stopping = false;
}
}
- mutex_unlock(tpebs_mtx_get());
+ mutex_unlock(&tpebs_mtx);
return ret;
}
@@ -729,7 +716,7 @@ int evsel__tpebs_read(struct evsel *evsel, int cpu_map_idx, int thread)
count = perf_counts(evsel->counts, cpu_map_idx, thread);
- mutex_lock(tpebs_mtx_get());
+ mutex_lock(&tpebs_mtx);
t = tpebs_retire_lat__find(evsel);
/*
* If reading the first tpebs result, send a ping to the record
@@ -738,10 +725,10 @@ int evsel__tpebs_read(struct evsel *evsel, int cpu_map_idx, int thread)
*/
if (t && &t->nd == tpebs_results.next) {
ret = tpebs_send_record_cmd(EVLIST_CTL_CMD_PING_TAG);
- mutex_unlock(tpebs_mtx_get());
+ mutex_unlock(&tpebs_mtx);
if (ret)
return ret;
- mutex_lock(tpebs_mtx_get());
+ mutex_lock(&tpebs_mtx);
}
if (t == NULL || t->stats.n == 0) {
/* No sample data, use default. */
@@ -780,7 +767,7 @@ int evsel__tpebs_read(struct evsel *evsel, int cpu_map_idx, int thread)
break;
}
}
- mutex_unlock(tpebs_mtx_get());
+ mutex_unlock(&tpebs_mtx);
if (old_count) {
count->val = old_count->val + val;
@@ -805,7 +792,7 @@ void evsel__tpebs_close(struct evsel *evsel)
{
struct tpebs_retire_lat *t;
- mutex_lock(tpebs_mtx_get());
+ mutex_lock(&tpebs_mtx);
t = tpebs_retire_lat__find(evsel);
if (t) {
list_del_init(&t->nd);
@@ -814,5 +801,5 @@ void evsel__tpebs_close(struct evsel *evsel)
if (list_empty(&tpebs_results))
tpebs_stop();
}
- mutex_unlock(tpebs_mtx_get());
+ mutex_unlock(&tpebs_mtx);
}
--
2.56.1.703.gf848ed807c-goog
next prev parent reply other threads:[~2026-11-13 16:42 UTC|newest]
Thread overview: 43+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-11-13 16:41 [PATCH v13 00/21] tools/perf: Adopt kernel compiler-context-analysis.h annotations Ian Rogers
2026-11-13 16:41 ` [PATCH v13 01/21] compiler-context-analysis: Avoid unused parameter warning in _context_unsafe_alias() Ian Rogers
2026-11-13 16:50 ` sashiko-bot
2026-11-13 16:41 ` [PATCH v13 02/21] tools headers compiler: Synchronize compiler_types.h with the kernel sources Ian Rogers
2026-11-13 16:56 ` sashiko-bot
2026-11-13 16:41 ` [PATCH v13 03/21] tools headers: Synchronize linux/compiler-context-analysis.h " Ian Rogers
2026-11-13 16:49 ` sashiko-bot
2026-11-13 16:41 ` [PATCH v13 04/21] perf mutex: Use kernel style compiler-context-analysis.h annotations Ian Rogers
2026-11-13 16:57 ` sashiko-bot
2026-11-13 16:41 ` [PATCH v13 05/21] perf build: Enable additional Clang thread-safety flags Ian Rogers
2026-11-13 16:56 ` sashiko-bot
2026-11-13 16:41 ` [PATCH v13 06/21] perf comm: Add __guarded_by annotations to struct comm_strs Ian Rogers
2026-11-13 17:02 ` sashiko-bot
2026-11-13 16:41 ` [PATCH v13 07/21] perf vdso: Fix unlocked __dsos__add() and race in __machine__addnew_vdso() Ian Rogers
2026-11-13 16:50 ` sashiko-bot
2026-11-13 16:41 ` [PATCH v13 08/21] perf dsos: Skip BPF and OOL DSOs in dsos__find_kernel_dso() Ian Rogers
2026-11-13 16:58 ` sashiko-bot
2026-11-13 16:41 ` [PATCH v13 09/21] perf dsos: Ensure DSOs in auxtrace, machine, and symbol are in dsos Ian Rogers
2026-11-13 16:59 ` sashiko-bot
2026-11-13 16:41 ` [PATCH v13 10/21] perf dso: Pass dso_data to close_data_fd() and dso__list_del() Ian Rogers
2026-11-13 16:55 ` sashiko-bot
2026-11-13 16:41 ` [PATCH v13 11/21] perf dso: Use DEFINE_MUTEX for dso__data_open_lock Ian Rogers
2026-11-13 16:52 ` sashiko-bot
2026-11-13 16:41 ` [PATCH v13 12/21] perf dsos: Use read lock fast path in dsos__findnew_id() Ian Rogers
2026-11-13 17:09 ` sashiko-bot
2026-11-13 16:41 ` [PATCH v13 13/21] perf dso: Expand context analysis annotations Ian Rogers
2026-11-13 16:58 ` sashiko-bot
2026-11-13 16:41 ` [PATCH v13 14/21] perf thread: Expand context analysis annotations to threads and namespaces_lock Ian Rogers
2026-11-13 16:59 ` sashiko-bot
2026-11-13 16:41 ` [PATCH v13 15/21] perf intel-tpebs: Fix race in tpebs_stop() and tpebs_cmd.out fd handling Ian Rogers
2026-11-13 17:13 ` sashiko-bot
2026-11-13 16:41 ` Ian Rogers [this message]
2026-11-13 17:09 ` [PATCH v13 16/21] perf intel-tpebs: Use DEFINE_MUTEX for tpebs_mtx and add lock annotations sashiko-bot
2026-11-13 16:41 ` [PATCH v13 17/21] perf config: Add __guarded_by and __must_hold annotations Ian Rogers
2026-11-13 17:01 ` sashiko-bot
2026-11-13 16:41 ` [PATCH v13 18/21] perf env: " Ian Rogers
2026-11-13 17:11 ` sashiko-bot
2026-11-13 16:41 ` [PATCH v13 19/21] perf maps: Fix lock inversion in maps__load_first() Ian Rogers
2026-11-13 17:10 ` sashiko-bot
2026-11-13 16:41 ` [PATCH v13 20/21] perf maps: Fix map index lookup fallback and removal Ian Rogers
2026-11-13 17:07 ` sashiko-bot
2026-11-13 16:41 ` [PATCH v13 21/21] perf maps: Add context analysis annotations Ian Rogers
2026-11-13 17:04 ` sashiko-bot
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