Add Paul Querna's io benchmarks

1 files changed, 107 insertions, 0 deletions

diff --git a/benchmark/io.c b/benchmark/io.c
new file mode 100644
index 0000000000..068d50ee1b
--- /dev/null
+++ b/benchmark/io.c
@@ -0,0 +1,107 @@
+/**
+ * gcc -o iotest io.c
+ */
+
+#include <unistd.h>
+#include <string.h>
+#include <fcntl.h>
+#include <time.h>
+#include <stdlib.h>
+#include <stdio.h>
+ 
+int tsize = 1000 * 1048576;
+const char *path = "/tmp/wt.dat";
+
+
+char* bufit(size_t l)
+{
+  char *p = malloc(l);
+  memset(p, '!', l);
+  return p;
+}
+
+void writetest(int size, size_t bsize)
+{
+  int i;
+  char *buf = bufit(bsize);
+  clock_t start, end;
+  double elapsed;
+  double mbps;
+
+  int fd = open(path, O_CREAT|O_WRONLY, 0644);
+  if (fd < 0) {
+    perror("open failed");
+    exit(254);
+  }
+
+  start = clock();
+  for (i = 0; i < size; i += bsize) {
+    int rv = write(fd, buf, bsize);
+    if (rv < 0) {
+      perror("write failed");
+      exit(254);
+    }
+  }
+#ifdef __linux__
+  fdatasync(fd);
+#else
+  fsync(fd);
+#endif
+  close(fd);
+  end = clock();
+  elapsed = ((double) (end - start)) / CLOCKS_PER_SEC;
+  mbps = ((tsize/elapsed)) / 1048576;
+  fprintf(stderr, "Wrote %d bytes in %03fs using %d byte buffers: %03fmB/s\n", size, elapsed, bsize, mbps);
+
+  free(buf);
+}
+
+void readtest(int size, size_t bsize)
+{
+  int i;
+  char *buf = bufit(bsize);
+  clock_t start, end;
+  double elapsed;
+  double mbps;
+
+  int fd = open(path, O_RDONLY, 0644);
+  if (fd < 0) {
+    perror("open failed");
+    exit(254);
+  }
+
+  start = clock();
+  for (i = 0; i < size; i += bsize) {
+    int rv = read(fd, buf, bsize);
+    if (rv < 0) {
+      perror("write failed");
+      exit(254);
+    }
+  }
+  close(fd);
+  end = clock();
+  elapsed = ((double) (end - start)) / CLOCKS_PER_SEC;
+  mbps = ((tsize/elapsed)) / 1048576;
+  fprintf(stderr, "Read %d bytes in %03fs using %d byte buffers: %03fmB/s\n", size, elapsed, bsize, mbps);
+
+  free(buf);
+}
+
+void cleanup() {
+  unlink(path);
+}
+
+int main()
+{
+  int i;
+  int bsizes[] = {1024, 4096, 8192, 16384, 32768, 65536, 0};
+
+  for (i = 0; bsizes[i] != 0; i++) {
+    writetest(tsize, bsizes[i]);
+  }
+  for (i = 0; bsizes[i] != 0; i++) {
+    readtest(tsize, bsizes[i]);
+  }
+  atexit(cleanup);
+  return 0;
+}