2005-07-12 Martin Hunt <hunt@redhat.com>

	* bench/run_bench (do_time): Use ttest instead of "time".
	Fix processor computation.

	* bench/ttest.c: Like "time.c" except takes an argument
	to adjust loop size. Also computes system time + user time
	instead of real time. Added a warmup loop to get
	consistent results from cpus which adjust speed based on load.

	* bench/time.c: Replaced by ttest.c

1 files changed, 82 insertions, 0 deletions

diff --git a/runtime/probes/bench/ttest.c b/runtime/probes/bench/ttest.c
new file mode 100644
index 00000000..eed641da
--- /dev/null
+++ b/runtime/probes/bench/ttest.c
@@ -0,0 +1,82 @@
+#include <stdio.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <sys/time.h>
+#include <stdlib.h>
+#include <sys/resource.h>
+#include <unistd.h>
+
+typedef unsigned long long uint64;
+struct rusage rstart;
+
+void start()
+{
+  getrusage (RUSAGE_SELF, &rstart);
+}
+
+uint64 usecs (struct timeval *tv)
+{
+  return tv->tv_sec * 1000000 + tv->tv_usec;
+}
+
+uint64 stop()
+{
+  struct rusage rend;
+  getrusage (RUSAGE_SELF, &rend);
+  uint64 utime = usecs(&rend.ru_utime) - usecs(&rstart.ru_utime);
+  uint64 stime = usecs(&rend.ru_stime) - usecs(&rstart.ru_stime);
+  return utime + stime;
+}
+
+void usage(char *name)
+{
+    printf ("Usage %s [time]\nWhere \"time\" is millions of times to loop.\n", name);
+    exit(1);
+}
+
+int main(int argc, char *argv[])
+{
+  int fd, i, n = 1;
+  char buf[1024];
+  uint64 nsecs;
+
+  if (argc > 2)
+    usage(argv[0]);
+
+  if (argc == 2) {
+    n = strtol(argv[1], NULL, 10);
+    if (n == 0)
+      usage(argv[0]);
+  }
+
+  fd = open ("foo", O_CREAT | O_RDWR);
+
+  /* large warmup time */
+  for (i = 0; i < n * 1000000; i++) {
+    if (write (fd, buf, 0) < 0)
+      perror("write");
+  }
+
+  start();
+  for (i = 0; i < n * 1000000; i++) {
+    if (read (fd, buf, 0) < 0)
+      perror("read");
+  }
+  nsecs = stop() / (n * 1000);
+
+  printf("%lld ", nsecs);
+
+  start();
+  for (i = 0; i < n * 1000000; i++) {
+    if (write (fd, buf, 0) < 0)
+      perror("write");
+  }
+  nsecs = stop() / (n * 1000);
+  close (fd);
+
+  printf("%lld\n", nsecs);
+  unlink("foo");
+
+  return 0;
+}