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    Annotation of /trunk/mkinitrd-magellan/busybox/miscutils/chrt.c

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    Revision 1123 - (hide annotations) (download)
    Wed Aug 18 21:56:57 2010 UTC (13 years, 10 months ago) by niro
    File MIME type: text/plain
    File size: 3219 byte(s) 
    -updated to busybox-1.17.1
    1 niro 816 /* 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 niro 1123
    14 niro 816 static const struct {
    15     int policy;
    16 niro 1123 char name[sizeof("SCHED_OTHER")];
    17 niro 816 } policies[] = {
    18     {SCHED_OTHER, "SCHED_OTHER"},
    19     {SCHED_FIFO, "SCHED_FIFO"},
    20     {SCHED_RR, "SCHED_RR"}
    21     };
    22    
    23 niro 1123 //TODO: add
    24     // -b, SCHED_BATCH
    25     // -i, SCHED_IDLE
    26    
    27 niro 816 static void show_min_max(int pol)
    28     {
    29 niro 1123 const char *fmt = "%s min/max priority\t: %u/%u\n";
    30 niro 816 int max, min;
    31 niro 1123
    32 niro 816 max = sched_get_priority_max(pol);
    33     min = sched_get_priority_min(pol);
    34 niro 1123 if ((max|min) < 0)
    35     fmt = "%s not supported\n";
    36     printf(fmt, policies[pol].name, min, max);
    37 niro 816 }
    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 niro 1123 if (!argv[0]) /* "-p <priority> <pid> [...]" */
    121 niro 816 goto print_rt_info;
    122    
    123 niro 1123 BB_EXECVP_or_die(argv);
    124 niro 816 }