diff options
Diffstat (limited to 'schedutils/chrt.c')
| -rw-r--r-- | schedutils/chrt.c | 255 |
1 files changed, 255 insertions, 0 deletions
diff --git a/schedutils/chrt.c b/schedutils/chrt.c new file mode 100644 index 0000000..7d6bb2d --- /dev/null +++ b/schedutils/chrt.c @@ -0,0 +1,255 @@ +/* + * chrt.c - chrt + * Command-line utility for manipulating a task's real-time attributes + * + * Robert Love <rml@tech9.net> + * 27-Apr-2002: initial version + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License, v2, as + * published by the Free Software Foundation + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. + * + * Copyright (C) 2004 Robert Love + */ + +#include <stdio.h> +#include <stdlib.h> +#include <sched.h> +#include <unistd.h> +#include <getopt.h> +#include <errno.h> +#include <err.h> + +#include "nls.h" + +/* the SCHED_BATCH is supported since Linux 2.6.16 + * -- temporary workaround for people with old glibc headers + */ +#if defined (__linux__) && !defined(SCHED_BATCH) +# define SCHED_BATCH 3 +#endif + +/* the SCHED_IDLE is supported since Linux 2.6.23 + * commit id 0e6aca43e08a62a48d6770e9a159dbec167bf4c6 + * -- temporary workaround for people with old glibc headers + */ +#if defined (__linux__) && !defined(SCHED_IDLE) +# define SCHED_IDLE 5 +#endif + +#ifndef ARRAY_SIZE +# define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0])) +#endif + +static void show_usage(int rc) +{ + fprintf(stdout, _( + "\nchrt - manipulate real-time attributes of a process.\n" + "\nSet policy:\n" + " chrt [options] <policy> <priority> {<pid> | <command> [<arg> ...]}\n" + "\nGet policy:\n" + " chrt [options] {<pid> | <command> [<arg> ...]}\n\n" + "\nScheduling policies:\n" + " -b | --batch set policy to SCHED_BATCH\n" + " -f | --fifo set policy to SCHED_FIFO\n" + " -i | --idle set policy to SCHED_IDLE\n" + " -o | --other set policy to SCHED_OTHER\n" + " -r | --rr set policy to SCHED_RR (default)\n" + "\nOptions:\n" + " -h | --help display this help\n" + " -p | --pid operate on existing given pid\n" + " -m | --max show min and max valid priorities\n" + " -v | --verbose display status information\n" + " -V | --version output version information\n\n")); + + exit(rc); +} + +static void show_rt_info(const char *what, pid_t pid) +{ + struct sched_param sp; + int policy; + + /* don't display "pid 0" as that is confusing */ + if (!pid) + pid = getpid(); + + policy = sched_getscheduler(pid); + if (policy == -1) + err(EXIT_FAILURE, _("failed to get pid %d's policy"), pid); + + printf(_("pid %d's %s scheduling policy: "), pid, what); + switch (policy) { + case SCHED_OTHER: + printf("SCHED_OTHER\n"); + break; + case SCHED_FIFO: + printf("SCHED_FIFO\n"); + break; +#ifdef SCHED_IDLE + case SCHED_IDLE: + printf("SCHED_IDLE\n"); + break; +#endif + case SCHED_RR: + printf("SCHED_RR\n"); + break; +#ifdef SCHED_BATCH + case SCHED_BATCH: + printf("SCHED_BATCH\n"); + break; +#endif + default: + printf(_("unknown\n")); + } + + if (sched_getparam(pid, &sp)) + err(EXIT_FAILURE, _("failed to get pid %d's attributes"), pid); + + printf(_("pid %d's %s scheduling priority: %d\n"), + pid, what, sp.sched_priority); +} + +static void show_min_max(void) +{ + int i; + int policies[] = { SCHED_OTHER, SCHED_FIFO, SCHED_RR, +#ifdef SCHED_BATCH + SCHED_BATCH, +#endif +#ifdef SCHED_IDLE + SCHED_IDLE, +#endif + }; + const char *names[] = { "OTHER", "FIFO", "RR", +#ifdef SCHED_BATCH + "BATCH", +#endif +#ifdef SCHED_IDLE + "IDLE", +#endif + }; + + for (i = 0; i < ARRAY_SIZE(policies); i++) { + int max = sched_get_priority_max(policies[i]); + int min = sched_get_priority_min(policies[i]); + + if (max >= 0 && min >= 0) + printf(_("SCHED_%s min/max priority\t: %d/%d\n"), + names[i], min, max); + else + printf(_("SCHED_%s not supported?\n"), names[i]); + } +} + +int main(int argc, char *argv[]) +{ + int i, policy = SCHED_RR, priority = 0, verbose = 0; + struct sched_param sp; + pid_t pid = -1; + + struct option longopts[] = { + { "batch", 0, NULL, 'b' }, + { "fifo", 0, NULL, 'f' }, + { "idle", 0, NULL, 'i' }, + { "pid", 0, NULL, 'p' }, + { "help", 0, NULL, 'h' }, + { "max", 0, NULL, 'm' }, + { "other", 0, NULL, 'o' }, + { "rr", 0, NULL, 'r' }, + { "verbose", 0, NULL, 'v' }, + { "version", 0, NULL, 'V' }, + { NULL, 0, NULL, 0 } + }; + + setlocale(LC_ALL, ""); + bindtextdomain(PACKAGE, LOCALEDIR); + textdomain(PACKAGE); + + while((i = getopt_long(argc, argv, "+bfiphmorvV", longopts, NULL)) != -1) + { + int ret = EXIT_FAILURE; + + switch (i) { + case 'b': +#ifdef SCHED_BATCH + policy = SCHED_BATCH; +#endif + break; + case 'f': + policy = SCHED_FIFO; + break; + case 'i': +#ifdef SCHED_IDLE + policy = SCHED_IDLE; +#endif + break; + case 'm': + show_min_max(); + return 0; + case 'o': + policy = SCHED_OTHER; + break; + case 'p': + errno = 0; + pid = strtol(argv[argc - 1], NULL, 10); + if (errno) + err(EXIT_FAILURE, _("failed to parse pid")); + break; + case 'r': + policy = SCHED_RR; + break; + case 'v': + verbose = 1; + break; + case 'V': + printf("chrt (%s)\n", PACKAGE_STRING); + return 0; + case 'h': + ret = EXIT_SUCCESS; + default: + show_usage(ret); + } + } + + if (((pid > -1) && argc - optind < 1) || ((pid == -1) && argc - optind < 2)) + show_usage(EXIT_FAILURE); + + if ((pid > -1) && (verbose || argc - optind == 1)) { + show_rt_info(_("current"), pid); + if (argc - optind == 1) + return EXIT_SUCCESS; + } + + errno = 0; + priority = strtol(argv[optind], NULL, 10); + if (errno) + err(EXIT_FAILURE, _("failed to parse priority")); + + if (pid == -1) + pid = 0; + sp.sched_priority = priority; + if (sched_setscheduler(pid, policy, &sp) == -1) + err(EXIT_FAILURE, _("failed to set pid %d's policy"), pid); + + if (verbose) + show_rt_info("new", pid); + + if (!pid) { + argv += optind + 1; + execvp(argv[0], argv); + perror("execvp"); + err(EXIT_FAILURE, _("failed to execute %s"), argv[0]); + } + + return EXIT_SUCCESS; +} |