From: Bill Joy <wnj@ucbvax.Berkeley.EDU>
Date: Mon, 12 Nov 1979 03:23:10 +0000 (-0800)
Subject: BSD 3 development
X-Git-Tag: BSD-3~748
X-Git-Url: https://git.subgeniuskitty.com/unix-history/.git/commitdiff_plain/1a51a8f3f93f18283d1f46cf379fd282cfdcea3e

BSD 3 development
Work on file usr/src/cmd/renice.c

Synthesized-from: 3bsd
---

diff --git a/usr/src/cmd/renice.c b/usr/src/cmd/renice.c
new file mode 100644
index 0000000000..afb1ac1413
--- /dev/null
+++ b/usr/src/cmd/renice.c
@@ -0,0 +1,73 @@
+#include <sys/param.h>
+#include <sys/proc.h>
+#include <stdio.h>
+
+struct	proc proc[NPROC];
+struct	{
+	char		name[8];
+	int		type;
+	unsigned	value;
+} nl[] = {
+	"_proc", 0, 0,
+	0, 0, 0, 0, 0, 0, 0, 0,	0, 0
+};
+
+/*
+ * Change the running priority (nice) of a process which is already
+ * running.
+ *
+ * Author: Kurt Shoens
+ */
+
+main(argc, argv)
+	char **argv;
+{
+	register struct proc *pp;
+	int pid, nice;
+	int addr, mem, a1, a2, coreaddr;
+
+	if (argc != 2 && argc != 3) {
+		fprintf(stderr, "usage: renice pid [ priority ]\n");
+		exit(1);
+	}
+	if (geteuid()) {
+		fprintf(stderr, "NOT super user\n");
+		exit(1);
+	}
+	pid = atoi(argv[1]);
+	nice = atoi(argc == 3 ? argv[2] : "19");
+	if (nice > 20)
+		nice = 20;
+	if (nice < -20)
+		nice = -20;
+	nice += NZERO;
+	mem = open("/dev/kmem", 2);
+	if (mem < 0) {
+		perror("/dev/kmem");
+		exit(1);
+	}
+	nlist("/vmunix", nl);
+	addr = nl[0].value;
+	if (addr == 0) {
+		fprintf(stderr, "/vmunix: _proc not in namelist");
+		exit(1);
+	}
+	lseek(mem, addr, 0);
+	read(mem, &proc[0], sizeof proc);
+	for (pp = &proc[0]; pp < &proc[NPROC]; pp++)
+		if (pp->p_pid == pid)
+			break;
+	if (pp >= &proc[NPROC]) {
+		fprintf(stderr, "%d: process not found\n", pid);
+		exit(1);
+	}
+	fprintf(stderr, "%d: old nice = %d, new nice = %d\n",
+			pid, 
+			pp->p_nice - NZERO,
+			nice - NZERO);
+	a1 = (int)&pp->p_nice;
+	a2 = (int)&proc[0];
+	coreaddr = a1-a2+addr;
+	lseek(mem, (long)coreaddr, 0);
+	write(mem, &nice, 1);
+}