blob: bd300605fd3ef3c4d06a060a9b7310bcf55ca920
1 | /* vi: set sw=4 ts=4: */ |
2 | /* |
3 | * ionice implementation for busybox based on linux-utils-ng 2.14 |
4 | * |
5 | * Copyright (C) 2008 by <u173034@informatik.uni-oldenburg.de> |
6 | * |
7 | * Licensed under GPLv2 or later, see file LICENSE in this source tree. |
8 | */ |
9 | |
10 | //usage:#define ionice_trivial_usage |
11 | //usage: "[-c 1-3] [-n 0-7] [-p PID] [PROG]" |
12 | //usage:#define ionice_full_usage "\n\n" |
13 | //usage: "Change I/O priority and class\n" |
14 | //usage: "\n -c Class. 1:realtime 2:best-effort 3:idle" |
15 | //usage: "\n -n Priority" |
16 | |
17 | #include <sys/syscall.h> |
18 | #include <asm/unistd.h> |
19 | #include "libbb.h" |
20 | |
21 | static int ioprio_set(int which, int who, int ioprio) |
22 | { |
23 | return syscall(SYS_ioprio_set, which, who, ioprio); |
24 | } |
25 | |
26 | static int ioprio_get(int which, int who) |
27 | { |
28 | return syscall(SYS_ioprio_get, which, who); |
29 | } |
30 | |
31 | enum { |
32 | IOPRIO_WHO_PROCESS = 1, |
33 | IOPRIO_WHO_PGRP, |
34 | IOPRIO_WHO_USER |
35 | }; |
36 | |
37 | enum { |
38 | IOPRIO_CLASS_NONE, |
39 | IOPRIO_CLASS_RT, |
40 | IOPRIO_CLASS_BE, |
41 | IOPRIO_CLASS_IDLE |
42 | }; |
43 | |
44 | static const char to_prio[] = "none\0realtime\0best-effort\0idle"; |
45 | |
46 | #define IOPRIO_CLASS_SHIFT 13 |
47 | |
48 | int ionice_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE; |
49 | int ionice_main(int argc UNUSED_PARAM, char **argv) |
50 | { |
51 | /* Defaults */ |
52 | int ioclass = 0; |
53 | int pri = 0; |
54 | int pid = 0; /* affect own porcess */ |
55 | int opt; |
56 | enum { |
57 | OPT_n = 1, |
58 | OPT_c = 2, |
59 | OPT_p = 4, |
60 | }; |
61 | |
62 | /* Numeric params */ |
63 | opt_complementary = "n+:c+:p+"; |
64 | /* '+': stop at first non-option */ |
65 | opt = getopt32(argv, "+n:c:p:", &pri, &ioclass, &pid); |
66 | argv += optind; |
67 | |
68 | if (opt & OPT_c) { |
69 | if (ioclass > 3) |
70 | bb_error_msg_and_die("bad class %d", ioclass); |
71 | // Do we need this (compat?)? |
72 | // if (ioclass == IOPRIO_CLASS_NONE) |
73 | // ioclass = IOPRIO_CLASS_BE; |
74 | // if (ioclass == IOPRIO_CLASS_IDLE) { |
75 | // //if (opt & OPT_n) |
76 | // // bb_error_msg("ignoring priority for idle class"); |
77 | // pri = 7; |
78 | // } |
79 | } |
80 | |
81 | if (!(opt & (OPT_n|OPT_c))) { |
82 | if (!(opt & OPT_p) && *argv) |
83 | pid = xatoi_positive(*argv); |
84 | |
85 | pri = ioprio_get(IOPRIO_WHO_PROCESS, pid); |
86 | if (pri == -1) |
87 | bb_perror_msg_and_die("ioprio_%cet", 'g'); |
88 | |
89 | ioclass = (pri >> IOPRIO_CLASS_SHIFT) & 0x3; |
90 | pri &= 0xff; |
91 | printf((ioclass == IOPRIO_CLASS_IDLE) ? "%s\n" : "%s: prio %d\n", |
92 | nth_string(to_prio, ioclass), pri); |
93 | } else { |
94 | //printf("pri=%d class=%d val=%x\n", |
95 | //pri, ioclass, pri | (ioclass << IOPRIO_CLASS_SHIFT)); |
96 | pri |= (ioclass << IOPRIO_CLASS_SHIFT); |
97 | if (ioprio_set(IOPRIO_WHO_PROCESS, pid, pri) == -1) |
98 | bb_perror_msg_and_die("ioprio_%cet", 's'); |
99 | if (argv[0]) { |
100 | BB_EXECVP_or_die(argv); |
101 | } |
102 | } |
103 | |
104 | return EXIT_SUCCESS; |
105 | } |
106 |