* 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.
+ * Licensed under GPLv2 or later, see file LICENSE in this source tree.
*/
+//usage:#define chrt_trivial_usage
+//usage: "[-prfom] [PRIO] [PID | PROG ARGS]"
+//usage:#define chrt_full_usage "\n\n"
+//usage: "Change scheduling priority and class for a process\n"
+//usage: "\n -p Operate on PID"
+//usage: "\n -r Set SCHED_RR class"
+//usage: "\n -f Set SCHED_FIFO class"
+//usage: "\n -o Set SCHED_OTHER class"
+//usage: "\n -m Show min/max priorities"
+//usage:
+//usage:#define chrt_example_usage
+//usage: "$ chrt -r 4 sleep 900; x=$!\n"
+//usage: "$ chrt -f -p 3 $x\n"
+//usage: "You need CAP_SYS_NICE privileges to set scheduling attributes of a process"
+
#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];
+ char name[sizeof("SCHED_OTHER")];
} policies[] = {
{SCHED_OTHER, "SCHED_OTHER"},
{SCHED_FIFO, "SCHED_FIFO"},
{SCHED_RR, "SCHED_RR"}
};
+//TODO: add
+// -b, SCHED_BATCH
+// -i, SCHED_IDLE
+
static void show_min_max(int pol)
{
- const char *fmt = "%s min/max priority\t: %d/%d\n\0%s not supported?\n";
+ const char *fmt = "%s min/max priority\t: %u/%u\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);
- }
+ if ((max|min) < 0)
+ fmt = "%s not supported\n";
+ printf(fmt, policies[pol].name, min, max);
}
#define OPT_m (1<<0)
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";
+ /* only one policy accepted */
+ opt_complementary = "r--fo:f--ro:o--rf";
opt = getopt32(argv, "+mprfo");
+ if (opt & OPT_m) { /* print min/max and exit */
+ show_min_max(SCHED_FIFO);
+ show_min_max(SCHED_RR);
+ show_min_max(SCHED_OTHER);
+ fflush_stdout_and_exit(EXIT_SUCCESS);
+ }
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 (!argv[0])
+ bb_show_usage();
if (opt & OPT_p) {
pid_str = *argv++;
if (*argv) { /* "-p <priority> <pid> [...]" */
print_rt_info:
pol = sched_getscheduler(pid);
if (pol < 0)
- bb_perror_msg_and_die("can't %cet pid %d's policy", 'g', pid);
+ bb_perror_msg_and_die("can't %cet pid %d's policy", 'g', (int)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);
+ bb_perror_msg_and_die("can't get pid %d's attributes", (int)pid);
printf("pid %d's %s scheduling priority: %d\n",
- pid, current_new, sp.sched_priority);
+ (int)pid, current_new, sp.sched_priority);
if (!*argv) {
/* Either it was just "-p <pid>",
* or it was "-p <priority> <pid>" and we came here
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);
+ bb_perror_msg_and_die("can't %cet pid %d's policy", 's', (int)pid);
if (!argv[0]) /* "-p <priority> <pid> [...]" */
goto print_rt_info;
- BB_EXECVP(argv[0], argv);
- bb_perror_msg_and_die("can't execute '%s'", argv[0]);
+ BB_EXECVP_or_die(argv);
}