Contents of /tags/mkinitrd-6_2_3/busybox/miscutils/chrt.c
Parent Directory | Revision Log
Revision 1054 -
(show annotations)
(download)
Mon May 31 20:54:44 2010 UTC (14 years, 3 months ago) by niro
File MIME type: text/plain
File size: 3243 byte(s)
Mon May 31 20:54:44 2010 UTC (14 years, 3 months ago) by niro
File MIME type: text/plain
File size: 3243 byte(s)
tagged 'mkinitrd-6_2_3'
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 | |
9 | #include <sched.h> |
10 | #include "libbb.h" |
11 | #ifndef _POSIX_PRIORITY_SCHEDULING |
12 | #warning your system may be foobared |
13 | #endif |
14 | static const struct { |
15 | int policy; |
16 | char name[12]; |
17 | } policies[] = { |
18 | {SCHED_OTHER, "SCHED_OTHER"}, |
19 | {SCHED_FIFO, "SCHED_FIFO"}, |
20 | {SCHED_RR, "SCHED_RR"} |
21 | }; |
22 | |
23 | static void show_min_max(int pol) |
24 | { |
25 | const char *fmt = "%s min/max priority\t: %d/%d\n\0%s not supported?\n"; |
26 | int max, min; |
27 | max = sched_get_priority_max(pol); |
28 | min = sched_get_priority_min(pol); |
29 | if (max >= 0 && min >= 0) |
30 | printf(fmt, policies[pol].name, min, max); |
31 | else { |
32 | fmt += 29; |
33 | printf(fmt, policies[pol].name); |
34 | } |
35 | } |
36 | |
37 | #define OPT_m (1<<0) |
38 | #define OPT_p (1<<1) |
39 | #define OPT_r (1<<2) |
40 | #define OPT_f (1<<3) |
41 | #define OPT_o (1<<4) |
42 | |
43 | int chrt_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE; |
44 | int chrt_main(int argc UNUSED_PARAM, char **argv) |
45 | { |
46 | pid_t pid = 0; |
47 | unsigned opt; |
48 | struct sched_param sp; |
49 | char *pid_str; |
50 | char *priority = priority; /* for compiler */ |
51 | const char *current_new; |
52 | int policy = SCHED_RR; |
53 | |
54 | /* at least 1 arg; only one policy accepted */ |
55 | opt_complementary = "-1:r--fo:f--ro:r--fo"; |
56 | opt = getopt32(argv, "+mprfo"); |
57 | if (opt & OPT_r) |
58 | policy = SCHED_RR; |
59 | if (opt & OPT_f) |
60 | policy = SCHED_FIFO; |
61 | if (opt & OPT_o) |
62 | policy = SCHED_OTHER; |
63 | if (opt & OPT_m) { /* print min/max */ |
64 | show_min_max(SCHED_FIFO); |
65 | show_min_max(SCHED_RR); |
66 | show_min_max(SCHED_OTHER); |
67 | fflush_stdout_and_exit(EXIT_SUCCESS); |
68 | } |
69 | |
70 | argv += optind; |
71 | if (opt & OPT_p) { |
72 | pid_str = *argv++; |
73 | if (*argv) { /* "-p <priority> <pid> [...]" */ |
74 | priority = pid_str; |
75 | pid_str = *argv; |
76 | } |
77 | /* else "-p <pid>", and *argv == NULL */ |
78 | pid = xatoul_range(pid_str, 1, ((unsigned)(pid_t)ULONG_MAX) >> 1); |
79 | } else { |
80 | priority = *argv++; |
81 | if (!*argv) |
82 | bb_show_usage(); |
83 | } |
84 | |
85 | current_new = "current\0new"; |
86 | if (opt & OPT_p) { |
87 | int pol; |
88 | print_rt_info: |
89 | pol = sched_getscheduler(pid); |
90 | if (pol < 0) |
91 | bb_perror_msg_and_die("can't %cet pid %d's policy", 'g', pid); |
92 | printf("pid %d's %s scheduling policy: %s\n", |
93 | pid, current_new, policies[pol].name); |
94 | if (sched_getparam(pid, &sp)) |
95 | bb_perror_msg_and_die("can't get pid %d's attributes", pid); |
96 | printf("pid %d's %s scheduling priority: %d\n", |
97 | pid, current_new, sp.sched_priority); |
98 | if (!*argv) { |
99 | /* Either it was just "-p <pid>", |
100 | * or it was "-p <priority> <pid>" and we came here |
101 | * for the second time (see goto below) */ |
102 | return EXIT_SUCCESS; |
103 | } |
104 | *argv = NULL; |
105 | current_new += 8; |
106 | } |
107 | |
108 | /* from the manpage of sched_getscheduler: |
109 | [...] sched_priority can have a value in the range 0 to 99. |
110 | [...] SCHED_OTHER or SCHED_BATCH must be assigned static priority 0. |
111 | [...] SCHED_FIFO or SCHED_RR can have static priority in 1..99 range. |
112 | */ |
113 | sp.sched_priority = xstrtou_range(priority, 0, policy != SCHED_OTHER ? 1 : 0, 99); |
114 | |
115 | if (sched_setscheduler(pid, policy, &sp) < 0) |
116 | bb_perror_msg_and_die("can't %cet pid %d's policy", 's', pid); |
117 | |
118 | if (!*argv) /* "-p <priority> <pid> [...]" */ |
119 | goto print_rt_info; |
120 | |
121 | BB_EXECVP(*argv, argv); |
122 | bb_simple_perror_msg_and_die(*argv); |
123 | } |