Commit | Line | Data |
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1a51a8f3 BJ |
1 | #include <sys/param.h> |
2 | #include <sys/proc.h> | |
3 | #include <stdio.h> | |
4 | ||
5 | struct proc proc[NPROC]; | |
6 | struct { | |
7 | char name[8]; | |
8 | int type; | |
9 | unsigned value; | |
10 | } nl[] = { | |
11 | "_proc", 0, 0, | |
12 | 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 | |
13 | }; | |
14 | ||
15 | /* | |
16 | * Change the running priority (nice) of a process which is already | |
17 | * running. | |
18 | * | |
19 | * Author: Kurt Shoens | |
20 | */ | |
21 | ||
22 | main(argc, argv) | |
23 | char **argv; | |
24 | { | |
25 | register struct proc *pp; | |
26 | int pid, nice; | |
27 | int addr, mem, a1, a2, coreaddr; | |
28 | ||
29 | if (argc != 2 && argc != 3) { | |
30 | fprintf(stderr, "usage: renice pid [ priority ]\n"); | |
31 | exit(1); | |
32 | } | |
33 | if (geteuid()) { | |
34 | fprintf(stderr, "NOT super user\n"); | |
35 | exit(1); | |
36 | } | |
37 | pid = atoi(argv[1]); | |
38 | nice = atoi(argc == 3 ? argv[2] : "19"); | |
39 | if (nice > 20) | |
40 | nice = 20; | |
41 | if (nice < -20) | |
42 | nice = -20; | |
43 | nice += NZERO; | |
44 | mem = open("/dev/kmem", 2); | |
45 | if (mem < 0) { | |
46 | perror("/dev/kmem"); | |
47 | exit(1); | |
48 | } | |
49 | nlist("/vmunix", nl); | |
50 | addr = nl[0].value; | |
51 | if (addr == 0) { | |
52 | fprintf(stderr, "/vmunix: _proc not in namelist"); | |
53 | exit(1); | |
54 | } | |
55 | lseek(mem, addr, 0); | |
56 | read(mem, &proc[0], sizeof proc); | |
57 | for (pp = &proc[0]; pp < &proc[NPROC]; pp++) | |
58 | if (pp->p_pid == pid) | |
59 | break; | |
60 | if (pp >= &proc[NPROC]) { | |
61 | fprintf(stderr, "%d: process not found\n", pid); | |
62 | exit(1); | |
63 | } | |
64 | fprintf(stderr, "%d: old nice = %d, new nice = %d\n", | |
65 | pid, | |
66 | pp->p_nice - NZERO, | |
67 | nice - NZERO); | |
68 | a1 = (int)&pp->p_nice; | |
69 | a2 = (int)&proc[0]; | |
70 | coreaddr = a1-a2+addr; | |
71 | lseek(mem, (long)coreaddr, 0); | |
72 | write(mem, &nice, 1); | |
73 | } |