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charset="UTF-8" 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 --- 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