[PATCH bpf-next 1/7] selftests/bpf: Add bench_force_done() for early benchmark completion

[Puranjay Mohan <puranjay@kernel.org>]

The bench framework waits for duration_sec to elapse before collecting
results.  Benchmarks that know exactly how many samples they need can
call bench_force_done() to signal completion early, avoiding wasted
wall-clock time.

Also refactor collect_measurements() to reuse bench_force_done()
instead of open-coding the same mutex/cond_signal sequence.

Signed-off-by: Puranjay Mohan <puranjay@kernel.org>
---
 tools/testing/selftests/bpf/bench.c | 14 +++++++++-----
 tools/testing/selftests/bpf/bench.h |  1 +
 2 files changed, 10 insertions(+), 5 deletions(-)

diff --git a/tools/testing/selftests/bpf/bench.c b/tools/testing/selftests/bpf/bench.c
index 029b3e21f438..47a4e72208d6 100644
--- a/tools/testing/selftests/bpf/bench.c
+++ b/tools/testing/selftests/bpf/bench.c
@@ -741,6 +741,13 @@ static void setup_benchmark(void)
 static pthread_mutex_t bench_done_mtx = PTHREAD_MUTEX_INITIALIZER;
 static pthread_cond_t bench_done = PTHREAD_COND_INITIALIZER;
 
+void bench_force_done(void)
+{
+	pthread_mutex_lock(&bench_done_mtx);
+	pthread_cond_signal(&bench_done);
+	pthread_mutex_unlock(&bench_done_mtx);
+}
+
 static void collect_measurements(long delta_ns) {
 	int iter = state.res_cnt++;
 	struct bench_res *res = &state.results[iter];
@@ -750,11 +757,8 @@ static void collect_measurements(long delta_ns) {
 	if (bench->report_progress)
 		bench->report_progress(iter, res, delta_ns);
 
-	if (iter == env.duration_sec + env.warmup_sec) {
-		pthread_mutex_lock(&bench_done_mtx);
-		pthread_cond_signal(&bench_done);
-		pthread_mutex_unlock(&bench_done_mtx);
-	}
+	if (iter == env.duration_sec + env.warmup_sec)
+		bench_force_done();
 }
 
 int main(int argc, char **argv)
diff --git a/tools/testing/selftests/bpf/bench.h b/tools/testing/selftests/bpf/bench.h
index 7cf21936e7ed..89a3fc72f70e 100644
--- a/tools/testing/selftests/bpf/bench.h
+++ b/tools/testing/selftests/bpf/bench.h
@@ -70,6 +70,7 @@ extern struct env env;
 extern const struct bench *bench;
 
 void setup_libbpf(void);
+void bench_force_done(void);
 void hits_drops_report_progress(int iter, struct bench_res *res, long delta_ns);
 void hits_drops_report_final(struct bench_res res[], int res_cnt);
 void false_hits_report_progress(int iter, struct bench_res *res, long delta_ns);
-- 
2.52.0