1 files changed, 43 insertions, 0 deletions
diff --git a/src/cmd/iostress/iostress.c b/src/cmd/iostress/iostress.c
new file mode 100644
index 0000000..ac555de
--- /dev/null
+++ b/src/cmd/iostress/iostress.c
@@ -0,0 +1,43 @@
+#include <camellia/syscalls.h>
+#include <errno.h>
+#include <stdio.h>
+#include <string.h>
+#include <x86intrin.h>
+
+int main(int argc, char **argv) {
+	long num_runs = 4;
+	long num_calls = 512;
+	long num_bytes = 1;
+	uint64_t *results;
+	char *inbuf;
+
+	if (argc > 1) num_runs  = strtol(argv[1], NULL, 0);
+	if (argc > 2) num_calls = strtol(argv[2], NULL, 0);
+	if (argc > 3) num_bytes = strtol(argv[3], NULL, 0);
+	if (argc > 4 || num_runs == 0 || num_calls == 0) {
+		fprintf(stderr, "usage: %s [num_runs] [num_calls] [num_bytes]\n", argv[0]);
+		return 1;
+	}
+
+	results = malloc(sizeof(*results) * num_runs);
+	inbuf = malloc(num_bytes);
+	memset(inbuf, '.', num_bytes);
+
+	for (long i = 0; i < num_runs; i++) {
+		uint64_t time = __rdtsc();
+		for (long j = 0; j < num_calls; j++)
+			_sys_write(1, inbuf, num_bytes, -1, 0);
+		results[i] = __rdtsc() - time;
+		_sys_write(1, "\n", 1, -1, 0);
+	}
+
+	uint64_t total = 0;
+	for (long i = 0; i < num_runs; i++) {
+		uint64_t scaled = results[i] / 3000;
+		total += scaled;
+		fprintf(stderr, "run %ld: %lu\n", i, scaled);
+	}
+	fprintf(stderr, "%lu calls, %lu bytes. avg %lu\n", num_calls, num_bytes, total / num_runs);
+
+	return 0;
+}