Contents of /tags/mkinitrd-6_3_2/busybox/miscutils/chrt.c
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Tue Sep 14 20:33:28 2010 UTC (14 years ago) by niro
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File size: 3219 byte(s)
Tue Sep 14 20:33:28 2010 UTC (14 years ago) by niro
File MIME type: text/plain
File size: 3219 byte(s)
tagged 'mkinitrd-6_3_2'
1 | /* vi: set sw=4 ts=4: */ |
2 | /* |
3 | * chrt - manipulate real-time attributes of a process |
4 | * Copyright (c) 2006-2007 Bernhard Reutner-Fischer |
5 | * |
6 | * Licensed under GPLv2 or later, see file LICENSE in this tarball for details. |
7 | */ |
8 | #include <sched.h> |
9 | #include "libbb.h" |
10 | #ifndef _POSIX_PRIORITY_SCHEDULING |
11 | #warning your system may be foobared |
12 | #endif |
13 | |
14 | static const struct { |
15 | int policy; |
16 | char name[sizeof("SCHED_OTHER")]; |
17 | } policies[] = { |
18 | {SCHED_OTHER, "SCHED_OTHER"}, |
19 | {SCHED_FIFO, "SCHED_FIFO"}, |
20 | {SCHED_RR, "SCHED_RR"} |
21 | }; |
22 | |
23 | //TODO: add |
24 | // -b, SCHED_BATCH |
25 | // -i, SCHED_IDLE |
26 | |
27 | static void show_min_max(int pol) |
28 | { |
29 | const char *fmt = "%s min/max priority\t: %u/%u\n"; |
30 | int max, min; |
31 | |
32 | max = sched_get_priority_max(pol); |
33 | min = sched_get_priority_min(pol); |
34 | if ((max|min) < 0) |
35 | fmt = "%s not supported\n"; |
36 | printf(fmt, policies[pol].name, min, max); |
37 | } |
38 | |
39 | #define OPT_m (1<<0) |
40 | #define OPT_p (1<<1) |
41 | #define OPT_r (1<<2) |
42 | #define OPT_f (1<<3) |
43 | #define OPT_o (1<<4) |
44 | |
45 | int chrt_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE; |
46 | int chrt_main(int argc UNUSED_PARAM, char **argv) |
47 | { |
48 | pid_t pid = 0; |
49 | unsigned opt; |
50 | struct sched_param sp; |
51 | char *pid_str; |
52 | char *priority = priority; /* for compiler */ |
53 | const char *current_new; |
54 | int policy = SCHED_RR; |
55 | |
56 | /* at least 1 arg; only one policy accepted */ |
57 | opt_complementary = "-1:r--fo:f--ro:r--fo"; |
58 | opt = getopt32(argv, "+mprfo"); |
59 | if (opt & OPT_r) |
60 | policy = SCHED_RR; |
61 | if (opt & OPT_f) |
62 | policy = SCHED_FIFO; |
63 | if (opt & OPT_o) |
64 | policy = SCHED_OTHER; |
65 | if (opt & OPT_m) { /* print min/max */ |
66 | show_min_max(SCHED_FIFO); |
67 | show_min_max(SCHED_RR); |
68 | show_min_max(SCHED_OTHER); |
69 | fflush_stdout_and_exit(EXIT_SUCCESS); |
70 | } |
71 | |
72 | argv += optind; |
73 | if (opt & OPT_p) { |
74 | pid_str = *argv++; |
75 | if (*argv) { /* "-p <priority> <pid> [...]" */ |
76 | priority = pid_str; |
77 | pid_str = *argv; |
78 | } |
79 | /* else "-p <pid>", and *argv == NULL */ |
80 | pid = xatoul_range(pid_str, 1, ((unsigned)(pid_t)ULONG_MAX) >> 1); |
81 | } else { |
82 | priority = *argv++; |
83 | if (!*argv) |
84 | bb_show_usage(); |
85 | } |
86 | |
87 | current_new = "current\0new"; |
88 | if (opt & OPT_p) { |
89 | int pol; |
90 | print_rt_info: |
91 | pol = sched_getscheduler(pid); |
92 | if (pol < 0) |
93 | bb_perror_msg_and_die("can't %cet pid %d's policy", 'g', pid); |
94 | printf("pid %d's %s scheduling policy: %s\n", |
95 | pid, current_new, policies[pol].name); |
96 | if (sched_getparam(pid, &sp)) |
97 | bb_perror_msg_and_die("can't get pid %d's attributes", pid); |
98 | printf("pid %d's %s scheduling priority: %d\n", |
99 | pid, current_new, sp.sched_priority); |
100 | if (!*argv) { |
101 | /* Either it was just "-p <pid>", |
102 | * or it was "-p <priority> <pid>" and we came here |
103 | * for the second time (see goto below) */ |
104 | return EXIT_SUCCESS; |
105 | } |
106 | *argv = NULL; |
107 | current_new += 8; |
108 | } |
109 | |
110 | /* from the manpage of sched_getscheduler: |
111 | [...] sched_priority can have a value in the range 0 to 99. |
112 | [...] SCHED_OTHER or SCHED_BATCH must be assigned static priority 0. |
113 | [...] SCHED_FIFO or SCHED_RR can have static priority in 1..99 range. |
114 | */ |
115 | sp.sched_priority = xstrtou_range(priority, 0, policy != SCHED_OTHER ? 1 : 0, 99); |
116 | |
117 | if (sched_setscheduler(pid, policy, &sp) < 0) |
118 | bb_perror_msg_and_die("can't %cet pid %d's policy", 's', pid); |
119 | |
120 | if (!argv[0]) /* "-p <priority> <pid> [...]" */ |
121 | goto print_rt_info; |
122 | |
123 | BB_EXECVP_or_die(argv); |
124 | } |