diff --git a/src/thread/bench.c b/src/thread/bench.c
new file mode 100644
index 0000000..10937aa
--- /dev/null
+++ b/src/thread/bench.c
@@ -0,0 +1,106 @@
+#define _XOPEN_SOURCE 700
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <pthread.h>
+#include <unistd.h>
+#include "test.h"
+
+void *emptyfunc(void *dummy) {
+	return 0;
+}
+
+void bench_pthread_createjoin_serial1(int N) {
+	int i;
+	pthread_t td;
+	void *dummy;
+
+	for (i=0; i<N; i++) {
+		pthread_create(&td, 0, emptyfunc, 0);
+		pthread_join(td, &dummy);
+	}
+}
+
+void bench_pthread_createjoin_serial2(int N) {
+	int i, j;
+	pthread_t td[50];
+	void *dummy;
+
+	for (j=0; j<N/(sizeof td/sizeof *td); j++) {
+		for (i=0; i<sizeof td/sizeof *td; i++)
+			pthread_create(td+i, 0, emptyfunc, 0);
+		for (i=0; i<sizeof td/sizeof *td; i++)
+			pthread_join(td[i], &dummy);
+	}
+}
+
+void bench_pthread_create_serial1(int N) {
+	int i,j;
+	pthread_attr_t attr;
+	pthread_t td[50];
+	void *dummy;
+
+	pthread_attr_init(&attr);
+	pthread_attr_setstacksize(&attr, 16384);
+	for (j=0; j<N/(sizeof td/sizeof *td); j++) {
+		for (i=0; i<sizeof td/sizeof *td; i++)
+			pthread_create(td+i, &attr, emptyfunc, 0);
+		stop_timer();
+		for (i=0; i<sizeof td/sizeof *td; i++)
+			pthread_join(td[i], &dummy);
+		start_timer();
+	}
+}
+
+static int lockN;
+void *lockunlock(void *mut)
+{
+	int i;
+	for (i=0; i<lockN; i++) {
+		pthread_mutex_lock(mut);
+		pthread_mutex_unlock(mut);
+	}
+	return 0;
+}
+
+void bench_pthread_uselesslock(int N) {
+	pthread_t td;
+	pthread_mutex_t mut = PTHREAD_MUTEX_INITIALIZER;
+	void *dummy;
+
+	lockN = N;
+	pthread_create(&td, 0, lockunlock, &mut);
+	pthread_join(td, &dummy);
+}
+
+void bench_pthread_createjoin_min1(int N) {
+	size_t i;
+	pthread_t td;
+	pthread_attr_t a;
+	void *dummy;
+
+	pthread_attr_init(&a);
+	pthread_attr_setstacksize(&a, sysconf(_SC_PAGESIZE));
+	pthread_attr_setguardsize(&a, 0);
+	for (i=0; i<N; i++) {
+		pthread_create(&td, &a, emptyfunc, 0);
+		pthread_join(td, &dummy);
+	}
+}
+
+void bench_pthread_createjoin_min2(int N) {
+	int i, j;
+	pthread_t td[50];
+	pthread_attr_t a;
+	void *dummy;
+
+	pthread_attr_init(&a);
+	pthread_attr_setstacksize(&a, sysconf(_SC_PAGESIZE));
+	pthread_attr_setguardsize(&a, 0);
+	for (j=0; j<N/(sizeof td/sizeof *td); j++) {
+		for (i=0; i<sizeof td/sizeof *td; i++)
+			pthread_create(td+i, &a, emptyfunc, 0);
+		for (i=0; i<sizeof td/sizeof *td; i++)
+			pthread_join(td[i], &dummy);
+	}
+}
diff --git a/src/thread/sem.c b/src/thread/sem.c
index 6840cd2..5bfcdfe 100644
--- a/src/thread/sem.c
+++ b/src/thread/sem.c
@@ -21,7 +21,6 @@
 void test_sem(void)
 {
 	int r;
-	void *res;
 	char buf[100];
 	struct timespec ts;
 	sem_t *sem, *sem2;