diff options
Diffstat (limited to 'release/src/router/busybox/miscutils/chrt.c')
| -rw-r--r-- | release/src/router/busybox/miscutils/chrt.c | 123 |
1 files changed, 123 insertions, 0 deletions
diff --git a/release/src/router/busybox/miscutils/chrt.c b/release/src/router/busybox/miscutils/chrt.c new file mode 100644 index 00000000..cc5660be --- /dev/null +++ b/release/src/router/busybox/miscutils/chrt.c @@ -0,0 +1,123 @@ +/* vi: set sw=4 ts=4: */ +/* + * chrt - manipulate real-time attributes of a process + * Copyright (c) 2006-2007 Bernhard Reutner-Fischer + * + * Licensed under GPLv2 or later, see file LICENSE in this tarball for details. + */ + +#include <sched.h> +#include "libbb.h" +#ifndef _POSIX_PRIORITY_SCHEDULING +#warning your system may be foobared +#endif +static const struct { + int policy; + char name[12]; +} policies[] = { + {SCHED_OTHER, "SCHED_OTHER"}, + {SCHED_FIFO, "SCHED_FIFO"}, + {SCHED_RR, "SCHED_RR"} +}; + +static void show_min_max(int pol) +{ + const char *fmt = "%s min/max priority\t: %d/%d\n\0%s not supported?\n"; + int max, min; + max = sched_get_priority_max(pol); + min = sched_get_priority_min(pol); + if (max >= 0 && min >= 0) + printf(fmt, policies[pol].name, min, max); + else { + fmt += 29; + printf(fmt, policies[pol].name); + } +} + +#define OPT_m (1<<0) +#define OPT_p (1<<1) +#define OPT_r (1<<2) +#define OPT_f (1<<3) +#define OPT_o (1<<4) + +int chrt_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE; +int chrt_main(int argc UNUSED_PARAM, char **argv) +{ + pid_t pid = 0; + unsigned opt; + struct sched_param sp; + char *pid_str; + char *priority = priority; /* for compiler */ + const char *current_new; + int policy = SCHED_RR; + + /* at least 1 arg; only one policy accepted */ + opt_complementary = "-1:r--fo:f--ro:r--fo"; + opt = getopt32(argv, "+mprfo"); + if (opt & OPT_r) + policy = SCHED_RR; + if (opt & OPT_f) + policy = SCHED_FIFO; + if (opt & OPT_o) + policy = SCHED_OTHER; + if (opt & OPT_m) { /* print min/max */ + show_min_max(SCHED_FIFO); + show_min_max(SCHED_RR); + show_min_max(SCHED_OTHER); + fflush_stdout_and_exit(EXIT_SUCCESS); + } + + argv += optind; + if (opt & OPT_p) { + pid_str = *argv++; + if (*argv) { /* "-p <priority> <pid> [...]" */ + priority = pid_str; + pid_str = *argv; + } + /* else "-p <pid>", and *argv == NULL */ + pid = xatoul_range(pid_str, 1, ((unsigned)(pid_t)ULONG_MAX) >> 1); + } else { + priority = *argv++; + if (!*argv) + bb_show_usage(); + } + + current_new = "current\0new"; + if (opt & OPT_p) { + int pol; + print_rt_info: + pol = sched_getscheduler(pid); + if (pol < 0) + bb_perror_msg_and_die("can't %cet pid %d's policy", 'g', pid); + printf("pid %d's %s scheduling policy: %s\n", + pid, current_new, policies[pol].name); + if (sched_getparam(pid, &sp)) + bb_perror_msg_and_die("can't get pid %d's attributes", pid); + printf("pid %d's %s scheduling priority: %d\n", + pid, current_new, sp.sched_priority); + if (!*argv) { + /* Either it was just "-p <pid>", + * or it was "-p <priority> <pid>" and we came here + * for the second time (see goto below) */ + return EXIT_SUCCESS; + } + *argv = NULL; + current_new += 8; + } + + /* from the manpage of sched_getscheduler: + [...] sched_priority can have a value in the range 0 to 99. + [...] SCHED_OTHER or SCHED_BATCH must be assigned static priority 0. + [...] SCHED_FIFO or SCHED_RR can have static priority in 1..99 range. + */ + sp.sched_priority = xstrtou_range(priority, 0, policy != SCHED_OTHER ? 1 : 0, 99); + + if (sched_setscheduler(pid, policy, &sp) < 0) + bb_perror_msg_and_die("can't %cet pid %d's policy", 's', pid); + + if (!*argv) /* "-p <priority> <pid> [...]" */ + goto print_rt_info; + + BB_EXECVP(*argv, argv); + bb_simple_perror_msg_and_die(*argv); +} |