125 lines
3.1 KiB
C
125 lines
3.1 KiB
C
/* vi: set sw=4 ts=4: */
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/*
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* chrt - manipulate real-time attributes of a process
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* Copyright (c) 2006-2007 Bernhard Fischer
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*
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* Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
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*/
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#include <sched.h>
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#include <getopt.h> /* optind */
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#include "libbb.h"
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#ifndef _POSIX_PRIORITY_SCHEDULING
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#warning your system may be foobared
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#endif
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static const struct {
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const int policy;
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const char const name[12];
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} policies[] = {
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{SCHED_OTHER, "SCHED_OTHER"},
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{SCHED_FIFO, "SCHED_FIFO"},
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{SCHED_RR, "SCHED_RR"}
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};
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static void show_min_max(int pol)
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{
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const char *fmt = "%s min/max priority\t: %d/%d\n\0%s not supported?\n";
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int max, min;
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max = sched_get_priority_max(pol);
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min = sched_get_priority_min(pol);
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if (max >= 0 && min >= 0)
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printf(fmt, policies[pol].name, min, max);
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else {
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fmt += 29;
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printf(fmt, policies[pol].name);
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}
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}
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#define OPT_m (1<<0)
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#define OPT_p (1<<1)
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#define OPT_r (1<<2)
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#define OPT_f (1<<3)
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#define OPT_o (1<<4)
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int chrt_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
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int chrt_main(int argc, char **argv)
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{
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pid_t pid = 0;
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unsigned opt;
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struct sched_param sp;
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char *p_opt = NULL, *priority = NULL;
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const char *state = "current\0new";
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int prio = 0, policy = SCHED_RR;
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opt_complementary = "r--fo:f--ro:r--fo"; /* only one policy accepted */
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opt = getopt32(argv, "+mp:rfo", &p_opt);
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if (opt & OPT_r)
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policy = SCHED_RR;
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if (opt & OPT_f)
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policy = SCHED_FIFO;
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if (opt & OPT_o)
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policy = SCHED_OTHER;
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if (opt & OPT_m) { /* print min/max */
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show_min_max(SCHED_FIFO);
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show_min_max(SCHED_RR);
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show_min_max(SCHED_OTHER);
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fflush_stdout_and_exit(EXIT_SUCCESS);
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}
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if (opt & OPT_p) {
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if (argc == optind+1) { /* -p <priority> <pid> */
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priority = p_opt;
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p_opt = argv[optind];
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}
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argv += optind; /* me -p <arg> */
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pid = xatoul_range(p_opt, 1, ULONG_MAX); /* -p <pid> */
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} else {
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argv += optind; /* me -p <arg> */
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priority = *argv;
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}
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if (priority) {
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/* from the manpage of sched_getscheduler:
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[...] sched_priority can have a value
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in the range 0 to 99.
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[...] SCHED_OTHER or SCHED_BATCH must be assigned
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the static priority 0. [...] SCHED_FIFO or
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SCHED_RR can have a static priority in the range 1 to 99.
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*/
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prio = xstrtol_range(priority, 0, policy == SCHED_OTHER
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? 0 : 1, 99);
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}
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if (opt & OPT_p) {
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int pol = 0;
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print_rt_info:
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pol = sched_getscheduler(pid);
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if (pol < 0)
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bb_perror_msg_and_die("failed to %cet pid %d's policy", 'g', pid);
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printf("pid %d's %s scheduling policy: %s\n",
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pid, state, policies[pol].name);
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if (sched_getparam(pid, &sp))
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bb_perror_msg_and_die("failed to get pid %d's attributes", pid);
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printf("pid %d's %s scheduling priority: %d\n",
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pid, state, sp.sched_priority);
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if (!*argv) /* no new prio given or we did print already, done. */
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return EXIT_SUCCESS;
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}
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sp.sched_priority = prio;
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if (sched_setscheduler(pid, policy, &sp) < 0)
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bb_perror_msg_and_die("failed to %cet pid %d's policy", 's', pid);
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if (opt & OPT_p) {
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state += 8;
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++argv;
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goto print_rt_info;
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}
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++argv;
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BB_EXECVP(*argv, argv);
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bb_simple_perror_msg_and_die(*argv);
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}
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#undef OPT_p
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#undef OPT_r
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#undef OPT_f
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#undef OPT_o
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#undef OPT_m
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