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 (file)
index 0000000..afb1ac1
--- /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);
+}