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Date:   Fri, 26 Aug 2022 09:42:32 -0700
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Subject: [PATCH v4 08/18] perf sched: Update use of pthread mutex
From:   Ian Rogers <irogers@google.com>
To:     Peter Zijlstra <peterz@infradead.org>,
        Ingo Molnar <mingo@redhat.com>,
        Arnaldo Carvalho de Melo <acme@kernel.org>,
        Mark Rutland <mark.rutland@arm.com>,
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        Alexey Bayduraev <alexey.v.bayduraev@linux.intel.com>,
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        Masami Hiramatsu <mhiramat@kernel.org>,
        Zechuan Chen <chenzechuan1@huawei.com>,
        Jason Wang <wangborong@cdjrlc.com>,
        Christophe JAILLET <christophe.jaillet@wanadoo.fr>,
        Remi Bernon <rbernon@codeweavers.com>,
        linux-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org,
        bpf@vger.kernel.org, llvm@lists.linux.dev
Cc:     Ian Rogers <irogers@google.com>
Content-Type: text/plain; charset="UTF-8"
Precedence: bulk

Switch to the use of mutex wrappers that provide better error
checking. Update cmd_sched so that we always explicitly destroy the
mutexes.

Signed-off-by: Ian Rogers <irogers@google.com>
---
 tools/perf/builtin-sched.c | 67 ++++++++++++++++++--------------------
 1 file changed, 32 insertions(+), 35 deletions(-)

diff --git a/tools/perf/builtin-sched.c b/tools/perf/builtin-sched.c
index 2f6cd1b8b662..7e4006d6b8bc 100644
--- a/tools/perf/builtin-sched.c
+++ b/tools/perf/builtin-sched.c
@@ -7,6 +7,7 @@
 #include "util/evlist.h"
 #include "util/evsel.h"
 #include "util/evsel_fprintf.h"
+#include "util/mutex.h"
 #include "util/symbol.h"
 #include "util/thread.h"
 #include "util/header.h"
@@ -184,8 +185,8 @@ struct perf_sched {
 	struct task_desc **pid_to_task;
 	struct task_desc **tasks;
 	const struct trace_sched_handler *tp_handler;
-	pthread_mutex_t	 start_work_mutex;
-	pthread_mutex_t	 work_done_wait_mutex;
+	struct mutex	 start_work_mutex;
+	struct mutex	 work_done_wait_mutex;
 	int		 profile_cpu;
 /*
  * Track the current task - that way we can know whether there's any
@@ -635,10 +636,8 @@ static void *thread_func(void *ctx)
 again:
 	ret = sem_post(&this_task->ready_for_work);
 	BUG_ON(ret);
-	ret = pthread_mutex_lock(&sched->start_work_mutex);
-	BUG_ON(ret);
-	ret = pthread_mutex_unlock(&sched->start_work_mutex);
-	BUG_ON(ret);
+	mutex_lock(&sched->start_work_mutex);
+	mutex_unlock(&sched->start_work_mutex);
 
 	cpu_usage_0 = get_cpu_usage_nsec_self(fd);
 
@@ -652,10 +651,8 @@ static void *thread_func(void *ctx)
 	ret = sem_post(&this_task->work_done_sem);
 	BUG_ON(ret);
 
-	ret = pthread_mutex_lock(&sched->work_done_wait_mutex);
-	BUG_ON(ret);
-	ret = pthread_mutex_unlock(&sched->work_done_wait_mutex);
-	BUG_ON(ret);
+	mutex_lock(&sched->work_done_wait_mutex);
+	mutex_unlock(&sched->work_done_wait_mutex);
 
 	goto again;
 }
@@ -672,10 +669,8 @@ static void create_tasks(struct perf_sched *sched)
 	err = pthread_attr_setstacksize(&attr,
 			(size_t) max(16 * 1024, (int)PTHREAD_STACK_MIN));
 	BUG_ON(err);
-	err = pthread_mutex_lock(&sched->start_work_mutex);
-	BUG_ON(err);
-	err = pthread_mutex_lock(&sched->work_done_wait_mutex);
-	BUG_ON(err);
+	mutex_lock(&sched->start_work_mutex);
+	mutex_lock(&sched->work_done_wait_mutex);
 	for (i = 0; i < sched->nr_tasks; i++) {
 		struct sched_thread_parms *parms = malloc(sizeof(*parms));
 		BUG_ON(parms == NULL);
@@ -699,7 +694,7 @@ static void wait_for_tasks(struct perf_sched *sched)
 
 	sched->start_time = get_nsecs();
 	sched->cpu_usage = 0;
-	pthread_mutex_unlock(&sched->work_done_wait_mutex);
+	mutex_unlock(&sched->work_done_wait_mutex);
 
 	for (i = 0; i < sched->nr_tasks; i++) {
 		task = sched->tasks[i];
@@ -707,12 +702,11 @@ static void wait_for_tasks(struct perf_sched *sched)
 		BUG_ON(ret);
 		sem_init(&task->ready_for_work, 0, 0);
 	}
-	ret = pthread_mutex_lock(&sched->work_done_wait_mutex);
-	BUG_ON(ret);
+	mutex_lock(&sched->work_done_wait_mutex);
 
 	cpu_usage_0 = get_cpu_usage_nsec_parent();
 
-	pthread_mutex_unlock(&sched->start_work_mutex);
+	mutex_unlock(&sched->start_work_mutex);
 
 	for (i = 0; i < sched->nr_tasks; i++) {
 		task = sched->tasks[i];
@@ -734,8 +728,7 @@ static void wait_for_tasks(struct perf_sched *sched)
 	sched->runavg_parent_cpu_usage = (sched->runavg_parent_cpu_usage * (sched->replay_repeat - 1) +
 					 sched->parent_cpu_usage)/sched->replay_repeat;
 
-	ret = pthread_mutex_lock(&sched->start_work_mutex);
-	BUG_ON(ret);
+	mutex_lock(&sched->start_work_mutex);
 
 	for (i = 0; i < sched->nr_tasks; i++) {
 		task = sched->tasks[i];
@@ -3430,8 +3423,6 @@ int cmd_sched(int argc, const char **argv)
 		},
 		.cmp_pid	      = LIST_HEAD_INIT(sched.cmp_pid),
 		.sort_list	      = LIST_HEAD_INIT(sched.sort_list),
-		.start_work_mutex     = PTHREAD_MUTEX_INITIALIZER,
-		.work_done_wait_mutex = PTHREAD_MUTEX_INITIALIZER,
 		.sort_order	      = default_sort_order,
 		.replay_repeat	      = 10,
 		.profile_cpu	      = -1,
@@ -3545,8 +3536,10 @@ int cmd_sched(int argc, const char **argv)
 		.fork_event	    = replay_fork_event,
 	};
 	unsigned int i;
-	int ret;
+	int ret = 0;
 
+	mutex_init(&sched.start_work_mutex);
+	mutex_init(&sched.work_done_wait_mutex);
 	for (i = 0; i < ARRAY_SIZE(sched.curr_pid); i++)
 		sched.curr_pid[i] = -1;
 
@@ -3558,11 +3551,10 @@ int cmd_sched(int argc, const char **argv)
 	/*
 	 * Aliased to 'perf script' for now:
 	 */
-	if (!strcmp(argv[0], "script"))
-		return cmd_script(argc, argv);
-
-	if (strlen(argv[0]) > 2 && strstarts("record", argv[0])) {
-		return __cmd_record(argc, argv);
+	if (!strcmp(argv[0], "script")) {
+		ret = cmd_script(argc, argv);
+	} else if (strlen(argv[0]) > 2 && strstarts("record", argv[0])) {
+		ret = __cmd_record(argc, argv);
 	} else if (strlen(argv[0]) > 2 && strstarts("latency", argv[0])) {
 		sched.tp_handler = &lat_ops;
 		if (argc > 1) {
@@ -3571,7 +3563,7 @@ int cmd_sched(int argc, const char **argv)
 				usage_with_options(latency_usage, latency_options);
 		}
 		setup_sorting(&sched, latency_options, latency_usage);
-		return perf_sched__lat(&sched);
+		ret = perf_sched__lat(&sched);
 	} else if (!strcmp(argv[0], "map")) {
 		if (argc) {
 			argc = parse_options(argc, argv, map_options, map_usage, 0);
@@ -3580,7 +3572,7 @@ int cmd_sched(int argc, const char **argv)
 		}
 		sched.tp_handler = &map_ops;
 		setup_sorting(&sched, latency_options, latency_usage);
-		return perf_sched__map(&sched);
+		ret = perf_sched__map(&sched);
 	} else if (strlen(argv[0]) > 2 && strstarts("replay", argv[0])) {
 		sched.tp_handler = &replay_ops;
 		if (argc) {
@@ -3588,7 +3580,7 @@ int cmd_sched(int argc, const char **argv)
 			if (argc)
 				usage_with_options(replay_usage, replay_options);
 		}
-		return perf_sched__replay(&sched);
+		ret = perf_sched__replay(&sched);
 	} else if (!strcmp(argv[0], "timehist")) {
 		if (argc) {
 			argc = parse_options(argc, argv, timehist_options,
@@ -3604,16 +3596,21 @@ int cmd_sched(int argc, const char **argv)
 				parse_options_usage(NULL, timehist_options, "w", true);
 			if (sched.show_next)
 				parse_options_usage(NULL, timehist_options, "n", true);
-			return -EINVAL;
+			ret = -EINVAL;
+			goto out;
 		}
 		ret = symbol__validate_sym_arguments();
 		if (ret)
-			return ret;
+			goto out;
 
-		return perf_sched__timehist(&sched);
+		ret = perf_sched__timehist(&sched);
 	} else {
 		usage_with_options(sched_usage, sched_options);
 	}
 
-	return 0;
+out:
+	mutex_destroy(&sched.start_work_mutex);
+	mutex_destroy(&sched.work_done_wait_mutex);
+
+	return ret;
 }
-- 
2.37.2.672.g94769d06f0-goog