Fix a bug under time's "-l" option. The values reported for average

shared memory size, average unshared data size, and average unshared
stack size were too high by a factor of 128/100, because the program
used a hard-coded hz value of 100.  The correct value is the frequency
of the statistics clock, currently 128.  The program now uses sysctl
to get the stathz value from the kernel.

Discussed with:	bde@freebsd.org (Bruce Evans)

1 files changed, 24 insertions, 1 deletions

diff --git a/usr.bin/time/time.c b/usr.bin/time/time.c
index ebb4a4f..e911d8c 100644
--- a/usr.bin/time/time.c
+++ b/usr.bin/time/time.c
@@ -45,8 +45,13 @@ static char sccsid[] = "@(#)time.c	8.1 (Berkeley) 6/6/93";
 #include <sys/time.h>
 #include <sys/resource.h>
 #include <sys/signal.h>
+#include <sys/sysctl.h>
+
+#include <err.h>
 #include <stdio.h>
 
+static int getstathz __P((void));
+
 main(argc, argv)
 	int argc;
 	char **argv;
@@ -102,7 +107,7 @@ main(argc, argv)
 	fprintf(stderr, "%9ld.%02ld sys\n",
 	    ru.ru_stime.tv_sec, ru.ru_stime.tv_usec/10000);
 	if (lflag) {
-		int hz = 100;			/* XXX */
+		int hz = getstathz();
 		u_long ticks;
 
 		ticks = hz * (ru.ru_utime.tv_sec + ru.ru_stime.tv_sec) +
@@ -146,3 +151,21 @@ main(argc, argv)
 	}
 	exit (status>>8);
 }
+
+/*
+ * Return the frequency of the kernel's statistics clock.
+ */
+static int
+getstathz()
+{
+	struct clockinfo clockrate;
+	int mib[2];
+	size_t size;
+
+	mib[0] = CTL_KERN;
+	mib[1] = KERN_CLOCKRATE;
+	size = sizeof clockrate;
+	if (sysctl(mib, 2, &clockrate, &size, NULL, 0) == -1)
+		err(1, "sysctl kern.clockrate");
+	return clockrate.stathz;
+}