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 v11 16/20] perf intel-tpebs: Use DEFINE_MUTEX for tpebs_mtx
Date: Fri, 6 Nov 2026 20:40:57 -0800 [thread overview]
Message-ID: <20261107044102.1506626-17-irogers@google.com> (raw)
In-Reply-To: <20261107044102.1506626-1-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.
Signed-off-by: Ian Rogers <irogers@google.com>
---
tools/perf/util/intel-tpebs.c | 91 +++++++++++++++--------------------
1 file changed, 38 insertions(+), 53 deletions(-)
diff --git a/tools/perf/util/intel-tpebs.c b/tools/perf/util/intel-tpebs.c
index 4b7464cfa0eb..525e38506737 100644
--- a/tools/perf/util/intel-tpebs.c
+++ b/tools/perf/util/intel-tpebs.c
@@ -38,12 +38,12 @@
bool tpebs_recording;
enum tpebs_mode tpebs_mode;
+static DEFINE_MUTEX(tpebs_mtx);
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 struct cond tpebs_cmd_cond = { .cond = PTHREAD_COND_INITIALIZER };
+static int control_fd[2] = { -1, -1 }, ack_fd[2] = { -1, -1 };
static bool tpebs_stopping;
static bool tpebs_cmd_in_flight;
static uint64_t tpebs_gen;
@@ -62,23 +62,8 @@ 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)
{
@@ -208,19 +193,19 @@ 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_cmd.pid == 0) {
/* Record 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;
}
/*
@@ -230,7 +215,7 @@ 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;
}
@@ -260,7 +245,7 @@ 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);
@@ -270,7 +255,7 @@ 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;
@@ -287,7 +272,7 @@ 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 = strlen(msg);
@@ -315,10 +300,10 @@ 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;
@@ -338,10 +323,10 @@ 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;
@@ -363,7 +348,7 @@ 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;
@@ -372,7 +357,7 @@ 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;
@@ -395,9 +380,9 @@ 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;
@@ -533,20 +518,20 @@ 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
@@ -582,9 +567,9 @@ 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. */
@@ -594,17 +579,17 @@ 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;
@@ -661,14 +646,14 @@ 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) {
@@ -699,7 +684,7 @@ int evsel__tpebs_open(struct evsel *evsel)
tpebs_stopping = false;
}
}
- mutex_unlock(tpebs_mtx_get());
+ mutex_unlock(&tpebs_mtx);
return ret;
}
@@ -719,7 +704,7 @@ 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
@@ -728,10 +713,10 @@ 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. */
@@ -770,7 +755,7 @@ 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;
@@ -795,7 +780,7 @@ 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);
@@ -804,5 +789,5 @@ void evsel__tpebs_close(struct evsel *evsel)
if (list_empty(&tpebs_results))
tpebs_stop();
}
- mutex_unlock(tpebs_mtx_get());
+ mutex_unlock(&tpebs_mtx);
}
--
2.56.0.455.g6c5a503b38-goog
next prev parent reply other threads:[~2026-11-07 4:41 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-11-07 4:40 [PATCH v11 00/20] tools/perf: Adopt kernel compiler-context-analysis.h annotations Ian Rogers
2026-11-07 4:40 ` [PATCH v11 01/20] compiler-context-analysis: Avoid unused parameter warning in _context_unsafe_alias() Ian Rogers
2026-11-07 4:40 ` [PATCH v11 02/20] tools headers compiler: Synchronize compiler_types.h with the kernel sources Ian Rogers
2026-11-07 4:40 ` [PATCH v11 03/20] tools headers: Synchronize linux/compiler-context-analysis.h " Ian Rogers
2026-11-07 4:40 ` [PATCH v11 04/20] perf mutex: Use kernel style compiler-context-analysis.h annotations Ian Rogers
2026-11-07 4:40 ` [PATCH v11 05/20] perf build: Enable additional Clang thread-safety flags Ian Rogers
2026-11-07 4:40 ` [PATCH v11 06/20] perf comm: Add __guarded_by annotations to struct comm_strs Ian Rogers
2026-11-07 4:40 ` [PATCH v11 07/20] perf vdso: Fix unlocked __dsos__add() and race in __machine__addnew_vdso() Ian Rogers
2026-11-07 4:40 ` [PATCH v11 08/20] perf dsos: Skip BPF and OOL DSOs in dsos__find_kernel_dso() Ian Rogers
2026-11-07 4:40 ` [PATCH v11 09/20] perf dsos: Ensure DSOs in auxtrace, machine, and symbol are in dsos Ian Rogers
2026-11-07 4:40 ` [PATCH v11 10/20] perf dso: Pass dso_data to close_data_fd() and dso__list_del() Ian Rogers
2026-11-07 4:40 ` [PATCH v11 11/20] perf dso: Use DEFINE_MUTEX for dso__data_open_lock Ian Rogers
2026-11-07 4:40 ` [PATCH v11 12/20] perf dsos: Use read lock fast path in dsos__findnew_id() Ian Rogers
2026-11-07 4:40 ` [PATCH v11 13/20] perf dso: Expand context analysis annotations Ian Rogers
2026-11-07 4:40 ` [PATCH v11 14/20] perf thread: Expand context analysis annotations to threads and namespaces_lock Ian Rogers
2026-11-07 4:40 ` [PATCH v11 15/20] perf intel-tpebs: Fix race in tpebs_stop() and tpebs_cmd.out fd handling Ian Rogers
2026-11-07 4:40 ` Ian Rogers [this message]
2026-11-07 4:40 ` [PATCH v11 17/20] perf config, intel-tpebs, env: Add __guarded_by and __must_hold annotations Ian Rogers
2026-11-07 4:40 ` [PATCH v11 18/20] perf maps: Fix lock inversion in maps__load_first() Ian Rogers
2026-11-07 4:41 ` [PATCH v11 19/20] perf maps: Fix map index lookup fallback and removal Ian Rogers
2026-11-07 4:41 ` [PATCH v11 20/20] perf maps: Add context analysis annotations Ian Rogers
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