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Date:   Fri, 26 Aug 2022 09:42:31 -0700
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Subject: [PATCH v4 07/18] perf record: 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>,
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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
for synth_lock.

Signed-off-by: Ian Rogers <irogers@google.com>
---
 tools/perf/builtin-record.c | 13 +++++++++----
 1 file changed, 9 insertions(+), 4 deletions(-)

diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
index 4713f0f3a6cf..a7b7a317d81b 100644
--- a/tools/perf/builtin-record.c
+++ b/tools/perf/builtin-record.c
@@ -21,6 +21,7 @@
 #include "util/evsel.h"
 #include "util/debug.h"
 #include "util/mmap.h"
+#include "util/mutex.h"
 #include "util/target.h"
 #include "util/session.h"
 #include "util/tool.h"
@@ -608,17 +609,18 @@ static int process_synthesized_event(struct perf_tool *tool,
 	return record__write(rec, NULL, event, event->header.size);
 }
 
+static struct mutex synth_lock;
+
 static int process_locked_synthesized_event(struct perf_tool *tool,
 				     union perf_event *event,
 				     struct perf_sample *sample __maybe_unused,
 				     struct machine *machine __maybe_unused)
 {
-	static pthread_mutex_t synth_lock = PTHREAD_MUTEX_INITIALIZER;
 	int ret;
 
-	pthread_mutex_lock(&synth_lock);
+	mutex_lock(&synth_lock);
 	ret = process_synthesized_event(tool, event, sample, machine);
-	pthread_mutex_unlock(&synth_lock);
+	mutex_unlock(&synth_lock);
 	return ret;
 }
 
@@ -1917,6 +1919,7 @@ static int record__synthesize(struct record *rec, bool tail)
 	}
 
 	if (rec->opts.nr_threads_synthesize > 1) {
+		mutex_init(&synth_lock);
 		perf_set_multithreaded();
 		f = process_locked_synthesized_event;
 	}
@@ -1930,8 +1933,10 @@ static int record__synthesize(struct record *rec, bool tail)
 						    rec->opts.nr_threads_synthesize);
 	}
 
-	if (rec->opts.nr_threads_synthesize > 1)
+	if (rec->opts.nr_threads_synthesize > 1) {
 		perf_set_singlethreaded();
+		mutex_destroy(&synth_lock);
+	}
 
 out:
 	return err;
-- 
2.37.2.672.g94769d06f0-goog