Reboot(8) normally waits 5 seconds after sending SIGTERMs to all

processes and then sends SIGKILLs. If a lot of processes are swapped
out, this delay may not be long enough, so processes such as an X
server may be killed before they have had time to clean up properly.

Make this delay more dynamic by waiting up to 60 seconds for swap
page-in activity to end. While I'm here, ANSIfy and remove a
`register' specifier.

1 files changed, 32 insertions, 10 deletions

diff --git a/sbin/reboot/reboot.c b/sbin/reboot/reboot.c
index be3c81b..9dae03d 100644
--- a/sbin/reboot/reboot.c
+++ b/sbin/reboot/reboot.c
@@ -47,6 +47,7 @@ static const char rcsid[] =
 
 #include <sys/reboot.h>
 #include <sys/types.h>
+#include <sys/sysctl.h>
 #include <signal.h>
 #include <err.h>
 #include <errno.h>
@@ -57,18 +58,17 @@ static const char rcsid[] =
 #include <string.h>
 #include <unistd.h>
 
-void usage __P((void));
+void usage(void);
+u_int get_pageins(void);
 
 int dohalt;
 
 int
-main(argc, argv)
-	int argc;
-	char *argv[];
+main(int argc, char *argv[])
 {
-	register int i;
 	struct passwd *pw;
-	int ch, howto, lflag, nflag, qflag, pflag, sverrno;
+	int ch, howto, i, lflag, nflag, qflag, pflag, sverrno;
+	u_int pageins;
 	char *p, *user;
 
 	if (strstr((p = rindex(*argv, '/')) ? p + 1 : *argv, "halt")) {
@@ -152,12 +152,19 @@ main(argc, argv)
 	/*
 	 * After the processes receive the signal, start the rest of the
 	 * buffers on their way.  Wait 5 seconds between the SIGTERM and
-	 * the SIGKILL to give everybody a chance.
+	 * the SIGKILL to give everybody a chance. If there is a lot of
+	 * paging activity then wait longer, up to a maximum of approx
+	 * 60 seconds.
 	 */
 	sleep(2);
-	if (!nflag)
-		sync();
-	sleep(3);
+	for (i = 0; i < 20; i++) {
+		pageins = get_pageins();
+		if (!nflag)
+			sync();
+		sleep(3);
+		if (get_pageins() == pageins)
+			break;
+	}
 
 	for (i = 1;; ++i) {
 		if (kill(-1, SIGKILL) == -1) {
@@ -190,3 +197,18 @@ usage()
 	    dohalt ? "halt" : "reboot");
 	exit(1);
 }
+
+u_int
+get_pageins()
+{
+	u_int pageins;
+	size_t len;
+
+	len = sizeof(pageins);
+	if (sysctlbyname("vm.stats.vm.v_swappgsin", &pageins, &len, NULL, 0)
+	    != 0) {
+		warnx("v_swappgsin");
+		return (0);
+	}
+	return pageins;
+}