[thirdparty/util-linux.git] / schedutils / chrt.c

/*
 * chrt.c - manipulate a task's real-time attributes
 *
 * 27-Apr-2002: initial version - Robert Love <rml@tech9.net>
 * 04-May-2011: make it thread-aware - Davidlohr Bueso <dave@gnu.org>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License, version 2, 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.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 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 <sys/time.h>
#include <sys/resource.h>

#include "c.h"
#include "nls.h"
#include "closestream.h"
#include "strutils.h"
#include "procutils.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

/* flag by sched_getscheduler() */
#if defined(__linux__) && !defined(SCHED_RESET_ON_FORK)
# define SCHED_RESET_ON_FORK 0x40000000
#endif

/* flag by sched_getattr() */
#if defined(__linux__) && !defined(SCHED_FLAG_RESET_ON_FORK)
# define SCHED_FLAG_RESET_ON_FORK 0x01
#endif

#if defined (__linux__) && !defined(HAVE_SCHED_SETATTR)
# include <sys/syscall.h>
#endif

/* usable kernel-headers, but old glibc-headers */
#if defined (__linux__) && !defined(SYS_sched_setattr) && defined(__NR_sched_setattr)
# define SYS_sched_setattr __NR_sched_setattr
#endif

#if defined (__linux__) && !defined(SYS_sched_getattr) && defined(__NR_sched_getattr)
# define SYS_sched_getattr __NR_sched_getattr
#endif

#if defined (__linux__) && !defined(HAVE_SCHED_SETATTR) && defined(SYS_sched_setattr)
# define HAVE_SCHED_SETATTR

struct sched_attr {
	uint32_t size;
	uint32_t sched_policy;
	uint64_t sched_flags;

	/* SCHED_NORMAL, SCHED_BATCH */
	int32_t sched_nice;

	/* SCHED_FIFO, SCHED_RR */
	uint32_t sched_priority;

	/* SCHED_DEADLINE (nsec) */
	uint64_t sched_runtime;
	uint64_t sched_deadline;
	uint64_t sched_period;
};

static int sched_setattr(pid_t pid, const struct sched_attr *attr, unsigned int flags)
{
	return syscall(SYS_sched_setattr, pid, attr, flags);
}

static int sched_getattr(pid_t pid, struct sched_attr *attr, unsigned int size, unsigned int flags)
{
	return syscall(SYS_sched_getattr, pid, attr, size, flags);
}
#endif

/* the SCHED_DEADLINE is supported since Linux 3.14
 * commit id aab03e05e8f7e26f51dee792beddcb5cca9215a5
 * -- sched_setattr() is required for this policy!
 */
#if defined (__linux__) && !defined(SCHED_DEADLINE) && defined(HAVE_SCHED_SETATTR)
# define SCHED_DEADLINE 6
#endif

/* control struct */
struct chrt_ctl {
	pid_t	pid;
	int	policy;				/* SCHED_* */
	int	priority;

	uint64_t runtime;			/* --sched-* options */
	uint64_t deadline;
	uint64_t period;

	unsigned int all_tasks : 1,		/* all threads of the PID */
		     reset_on_fork : 1,		/* SCHED_RESET_ON_FORK */
		     altered : 1,		/* sched_set**() used */
		     verbose : 1;		/* verbose output */
};

static void __attribute__((__noreturn__)) usage(void)
{
	FILE *out = stdout;

	fputs(_("Show or change the real-time scheduling attributes of a process.\n"), out);
	fputs(USAGE_SEPARATOR, out);
	fputs(_("Set policy:\n"
	" chrt [options] <priority> <command> [<arg>...]\n"
	" chrt [options] --pid <priority> <pid>\n"), out);
	fputs(USAGE_SEPARATOR, out);
	fputs(_("Get policy:\n"
	" chrt [options] -p <pid>\n"), out);

	fputs(USAGE_SEPARATOR, out);
	fputs(_("Policy options:\n"), out);
	fputs(_(" -b, --batch          set policy to SCHED_BATCH\n"), out);
	fputs(_(" -d, --deadline       set policy to SCHED_DEADLINE\n"), out);
	fputs(_(" -f, --fifo           set policy to SCHED_FIFO\n"), out);
	fputs(_(" -i, --idle           set policy to SCHED_IDLE\n"), out);
	fputs(_(" -o, --other          set policy to SCHED_OTHER\n"), out);
	fputs(_(" -r, --rr             set policy to SCHED_RR (default)\n"), out);

	fputs(USAGE_SEPARATOR, out);
	fputs(_("Scheduling options:\n"), out);
	fputs(_(" -R, --reset-on-fork       set SCHED_RESET_ON_FORK for FIFO or RR\n"), out);
	fputs(_(" -T, --sched-runtime <ns>  runtime parameter for DEADLINE\n"), out);
	fputs(_(" -P, --sched-period <ns>   period parameter for DEADLINE\n"), out);
	fputs(_(" -D, --sched-deadline <ns> deadline parameter for DEADLINE\n"), out);

	fputs(USAGE_SEPARATOR, out);
	fputs(_("Other options:\n"), out);
	fputs(_(" -a, --all-tasks      operate on all the tasks (threads) for a given pid\n"), out);
	fputs(_(" -m, --max            show min and max valid priorities\n"), out);
	fputs(_(" -p, --pid            operate on existing given pid\n"), out);
	fputs(_(" -v, --verbose        display status information\n"), out);

	fputs(USAGE_SEPARATOR, out);
	printf(USAGE_HELP_OPTIONS(22));

	printf(USAGE_MAN_TAIL("chrt(1)"));
	exit(EXIT_SUCCESS);
}

static const char *get_policy_name(int policy)
{
	switch (policy) {
	case SCHED_OTHER:
		return "SCHED_OTHER";
	case SCHED_FIFO:
#ifdef SCHED_RESET_ON_FORK
	case SCHED_FIFO | SCHED_RESET_ON_FORK:
#endif
		return "SCHED_FIFO";
#ifdef SCHED_IDLE
	case SCHED_IDLE:
		return "SCHED_IDLE";
#endif
	case SCHED_RR:
#ifdef SCHED_RESET_ON_FORK
	case SCHED_RR | SCHED_RESET_ON_FORK:
#endif
		return "SCHED_RR";
#ifdef SCHED_BATCH
	case SCHED_BATCH:
		return "SCHED_BATCH";
#endif
#ifdef SCHED_DEADLINE
	case SCHED_DEADLINE:
		return "SCHED_DEADLINE";
#endif
	default:
		break;
	}

	return _("unknown");
}

static void show_sched_pid_info(struct chrt_ctl *ctl, pid_t pid)
{
	int policy = -1, reset_on_fork = 0, prio = 0;
#ifdef SCHED_DEADLINE
	uint64_t deadline = 0, runtime = 0, period = 0;
#endif

	/* don't display "pid 0" as that is confusing */
	if (!pid)
		pid = getpid();

	errno = 0;

	/*
	 * New way
	 */
#ifdef HAVE_SCHED_SETATTR
	{
		struct sched_attr sa;

		if (sched_getattr(pid, &sa, sizeof(sa), 0) != 0) {
			if (errno == ENOSYS)
				goto fallback;
			err(EXIT_FAILURE, _("failed to get pid %d's policy"), pid);
		}

		policy = sa.sched_policy;
		prio = sa.sched_priority;
		reset_on_fork = sa.sched_flags & SCHED_FLAG_RESET_ON_FORK;
		deadline = sa.sched_deadline;
		runtime = sa.sched_runtime;
		period = sa.sched_period;
	}

	/*
	 * Old way
	 */
fallback:
	if (errno == ENOSYS)
#endif
	{
		struct sched_param sp;

		policy = sched_getscheduler(pid);
		if (policy == -1)
			err(EXIT_FAILURE, _("failed to get pid %d's policy"), pid);

		if (sched_getparam(pid, &sp) != 0)
			err(EXIT_FAILURE, _("failed to get pid %d's attributes"), pid);
		else
			prio = sp.sched_priority;
# ifdef SCHED_RESET_ON_FORK
		if (policy == (SCHED_FIFO|SCHED_RESET_ON_FORK) || policy == (SCHED_BATCH|SCHED_RESET_ON_FORK))
			reset_on_fork = 1;
# endif
	}

	if (ctl->altered)
		printf(_("pid %d's new scheduling policy: %s"), pid, get_policy_name(policy));
	else
		printf(_("pid %d's current scheduling policy: %s"), pid, get_policy_name(policy));

	if (reset_on_fork)
		printf("|SCHED_RESET_ON_FORK");
	putchar('\n');

	if (ctl->altered)
		printf(_("pid %d's new scheduling priority: %d\n"), pid, prio);
	else
		printf(_("pid %d's current scheduling priority: %d\n"), pid, prio);

#ifdef SCHED_DEADLINE
	if (policy == SCHED_DEADLINE) {
		if (ctl->altered)
			printf(_("pid %d's new runtime/deadline/period parameters: %ju/%ju/%ju\n"),
					pid, runtime, deadline, period);
		else
			printf(_("pid %d's current runtime/deadline/period parameters: %ju/%ju/%ju\n"),
					pid, runtime, deadline, period);
	}
#endif
}


static void show_sched_info(struct chrt_ctl *ctl)
{
	if (ctl->all_tasks) {
		pid_t tid;
		struct proc_tasks *ts = proc_open_tasks(ctl->pid);

		if (!ts)
			err(EXIT_FAILURE, _("cannot obtain the list of tasks"));

		while (!proc_next_tid(ts, &tid))
			show_sched_pid_info(ctl, tid);

		proc_close_tasks(ts);
	} else
		show_sched_pid_info(ctl, ctl->pid);
}

static void show_min_max(void)
{
	unsigned long i;
	int policies[] = {
		SCHED_OTHER,
		SCHED_FIFO,
		SCHED_RR,
#ifdef SCHED_BATCH
		SCHED_BATCH,
#endif
#ifdef SCHED_IDLE
		SCHED_IDLE,
#endif
#ifdef SCHED_DEADLINE
		SCHED_DEADLINE,
#endif
	};

	for (i = 0; i < ARRAY_SIZE(policies); i++) {
		int plc = policies[i];
		int max = sched_get_priority_max(plc);
		int min = sched_get_priority_min(plc);

		if (max >= 0 && min >= 0)
			printf(_("%s min/max priority\t: %d/%d\n"),
					get_policy_name(plc), min, max);
		else
			printf(_("%s not supported?\n"), get_policy_name(plc));
	}
}

static int set_sched_one_by_setscheduler(struct chrt_ctl *ctl, pid_t pid)
{
	struct sched_param sp = { .sched_priority = ctl->priority };
	int policy = ctl->policy;

	errno = 0;
# ifdef SCHED_RESET_ON_FORK
	if (ctl->reset_on_fork)
		policy |= SCHED_RESET_ON_FORK;
# endif
	return sched_setscheduler(pid, policy, &sp);
}


#ifndef HAVE_SCHED_SETATTR
static int set_sched_one(struct chrt_ctl *ctl, pid_t pid)
{
	return set_sched_one_by_setscheduler(ctl, pid);
}

#else /* !HAVE_SCHED_SETATTR */
static int set_sched_one(struct chrt_ctl *ctl, pid_t pid)
{
	struct sched_attr sa = { .size = sizeof(struct sched_attr) };

	/* old API is good enough for non-deadline */
	if (ctl->policy != SCHED_DEADLINE)
		return set_sched_one_by_setscheduler(ctl, pid);

	/* no changeed by chrt, follow the current setting */
	sa.sched_nice = getpriority(PRIO_PROCESS, pid);

	/* use main() to check if the setting makes sense */
	sa.sched_policy	  = ctl->policy;
	sa.sched_priority = ctl->priority;
	sa.sched_runtime  = ctl->runtime;
	sa.sched_period   = ctl->period;
	sa.sched_deadline = ctl->deadline;

# ifdef SCHED_RESET_ON_FORK
	if (ctl->reset_on_fork)
		sa.sched_flags |= SCHED_RESET_ON_FORK;
# endif
	errno = 0;
	return sched_setattr(pid, &sa, 0);
}
#endif /* HAVE_SCHED_SETATTR */

static void set_sched(struct chrt_ctl *ctl)
{
	if (ctl->all_tasks) {
		pid_t tid;
		struct proc_tasks *ts = proc_open_tasks(ctl->pid);

		if (!ts)
			err(EXIT_FAILURE, _("cannot obtain the list of tasks"));

		while (!proc_next_tid(ts, &tid))
			if (set_sched_one(ctl, tid) == -1)
				err(EXIT_FAILURE, _("failed to set tid %d's policy"), tid);

		proc_close_tasks(ts);

	} else if (set_sched_one(ctl, ctl->pid) == -1)
		err(EXIT_FAILURE, _("failed to set pid %d's policy"), ctl->pid);

	ctl->altered = 1;
}

int main(int argc, char **argv)
{
	struct chrt_ctl _ctl = { .pid = -1, .policy = SCHED_RR }, *ctl = &_ctl;
	int c;

	static const struct option longopts[] = {
		{ "all-tasks",  no_argument, NULL, 'a' },
		{ "batch",	no_argument, NULL, 'b' },
		{ "deadline",   no_argument, NULL, 'd' },
		{ "fifo",	no_argument, NULL, 'f' },
		{ "idle",	no_argument, NULL, 'i' },
		{ "pid",	no_argument, NULL, 'p' },
		{ "help",	no_argument, NULL, 'h' },
		{ "max",        no_argument, NULL, 'm' },
		{ "other",	no_argument, NULL, 'o' },
		{ "rr",		no_argument, NULL, 'r' },
		{ "sched-runtime",  required_argument, NULL, 'T' },
		{ "sched-period",   required_argument, NULL, 'P' },
		{ "sched-deadline", required_argument, NULL, 'D' },
		{ "reset-on-fork",  no_argument,       NULL, 'R' },
		{ "verbose",	no_argument, NULL, 'v' },
		{ "version",	no_argument, NULL, 'V' },
		{ NULL,		no_argument, NULL, 0 }
	};

	setlocale(LC_ALL, "");
	bindtextdomain(PACKAGE, LOCALEDIR);
	textdomain(PACKAGE);
	close_stdout_atexit();

	while((c = getopt_long(argc, argv, "+abdD:fiphmoP:T:rRvV", longopts, NULL)) != -1)
	{
		switch (c) {
		case 'a':
			ctl->all_tasks = 1;
			break;
		case 'b':
#ifdef SCHED_BATCH
			ctl->policy = SCHED_BATCH;
#endif
			break;

		case 'd':
#ifdef SCHED_DEADLINE
			ctl->policy = SCHED_DEADLINE;
#endif
			break;
		case 'f':
			ctl->policy = SCHED_FIFO;
			break;
		case 'R':
			ctl->reset_on_fork = 1;
			break;
		case 'i':
#ifdef SCHED_IDLE
			ctl->policy = SCHED_IDLE;
#endif
			break;
		case 'm':
			show_min_max();
			return EXIT_SUCCESS;
		case 'o':
			ctl->policy = SCHED_OTHER;
			break;
		case 'p':
			errno = 0;
			ctl->pid = strtos32_or_err(argv[argc - 1], _("invalid PID argument"));
			break;
		case 'r':
			ctl->policy = SCHED_RR;
			break;
		case 'v':
			ctl->verbose = 1;
			break;
		case 'T':
			ctl->runtime = strtou64_or_err(optarg, _("invalid runtime argument"));
			break;
		case 'P':
			ctl->period = strtou64_or_err(optarg, _("invalid period argument"));
			break;
		case 'D':
			ctl->deadline = strtou64_or_err(optarg, _("invalid deadline argument"));
			break;

		case 'V':
			print_version(EXIT_SUCCESS);
		case 'h':
			usage();
		default:
			errtryhelp(EXIT_FAILURE);
		}
	}

	if (((ctl->pid > -1) && argc - optind < 1) ||
	    ((ctl->pid == -1) && argc - optind < 2)) {
		warnx(_("bad usage"));
		errtryhelp(EXIT_FAILURE);
}

	if ((ctl->pid > -1) && (ctl->verbose || argc - optind == 1)) {
		show_sched_info(ctl);
		if (argc - optind == 1)
			return EXIT_SUCCESS;
	}

	errno = 0;
	ctl->priority = strtos32_or_err(argv[optind], _("invalid priority argument"));

#ifdef SCHED_RESET_ON_FORK
	if (ctl->reset_on_fork && ctl->policy != SCHED_FIFO && ctl->policy != SCHED_RR)
		errx(EXIT_FAILURE, _("--reset-on-fork option is supported for "
				     "SCHED_FIFO and SCHED_RR policies only"));
#endif
#ifdef SCHED_DEADLINE
	if ((ctl->runtime || ctl->deadline || ctl->period) && ctl->policy != SCHED_DEADLINE)
		errx(EXIT_FAILURE, _("--sched-{runtime,deadline,period} options "
				     "are supported for SCHED_DEADLINE only"));
	if (ctl->policy == SCHED_DEADLINE) {
		/* The basic rule is runtime <= deadline <= period, so we can
		 * make deadline and runtime optional on command line. Note we
		 * don't check any values or set any defaults, it's kernel
		 * responsibility.
		 */
		if (ctl->deadline == 0)
			ctl->deadline = ctl->period;
		if (ctl->runtime == 0)
			ctl->runtime = ctl->deadline;
	}
#else
	if (ctl->runtime || ctl->deadline || ctl->period)
		errx(EXIT_FAILURE, _("SCHED_DEADLINE is unsupported"));
#endif
	if (ctl->pid == -1)
		ctl->pid = 0;
	if (ctl->priority < sched_get_priority_min(ctl->policy) ||
	    sched_get_priority_max(ctl->policy) < ctl->priority)
		errx(EXIT_FAILURE,
		     _("unsupported priority value for the policy: %d: see --max for valid range"),
		     ctl->priority);
	set_sched(ctl);

	if (ctl->verbose)
		show_sched_info(ctl);

	if (!ctl->pid) {
		argv += optind + 1;
		execvp(argv[0], argv);
		errexec(argv[0]);
	}

	return EXIT_SUCCESS;
}
Commit	Line	Data
48d7b13a	1	/*
a7560c06	2	* chrt.c - manipulate a task's real-time attributes
48d7b13a	3	*
a7560c06 BS	4	* 27-Apr-2002: initial version - Robert Love <rml@tech9.net>
a7560c06 BS	5	* 04-May-2011: make it thread-aware - Davidlohr Bueso <dave@gnu.org>
48d7b13a KZ	6	*
48d7b13a KZ	7	* This program is free software; you can redistribute it and/or modify
a7560c06	8	* it under the terms of the GNU General Public License, version 2, as
48d7b13a KZ	9	* published by the Free Software Foundation
	10	*
	11	* This program is distributed in the hope that it will be useful,
	12	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	13	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	14	* GNU General Public License for more details.
	15	*
7cebf0bb SK	16	* You should have received a copy of the GNU General Public License along
	17	* with this program; if not, write to the Free Software Foundation, Inc.,
	18	* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
48d7b13a KZ	19	*
	20	* Copyright (C) 2004 Robert Love
	21	*/
	22
48d7b13a KZ	23	#include <stdio.h>
	24	#include <stdlib.h>
	25	#include <sched.h>
	26	#include <unistd.h>
	27	#include <getopt.h>
	28	#include <errno.h>
88b60f0b KZ	29	#include <sys/time.h>
88b60f0b KZ	30	#include <sys/resource.h>
bd9d9f05	31
b6534e4f	32	#include "c.h"
bd9d9f05	33	#include "nls.h"
ed8ec2a6	34	#include "closestream.h"
8abcf290	35	#include "strutils.h"
78904e76	36	#include "procutils.h"
24295096	37
09dd84ca KZ	38	/* the SCHED_BATCH is supported since Linux 2.6.16
	39	* -- temporary workaround for people with old glibc headers
	40	*/
b64279da	41	#if defined (__linux__) && !defined(SCHED_BATCH)
09dd84ca KZ	42	# define SCHED_BATCH 3
	43	#endif
	44
c779d6e9 MS	45	/* the SCHED_IDLE is supported since Linux 2.6.23
	46	* commit id 0e6aca43e08a62a48d6770e9a159dbec167bf4c6
	47	* -- temporary workaround for people with old glibc headers
	48	*/
b64279da	49	#if defined (__linux__) && !defined(SCHED_IDLE)
c779d6e9 MS	50	# define SCHED_IDLE 5
	51	#endif
	52
acde3a05	53	/* flag by sched_getscheduler() */
0fefbedc	54	#if defined(__linux__) && !defined(SCHED_RESET_ON_FORK)
acde3a05 KZ	55	# define SCHED_RESET_ON_FORK 0x40000000
	56	#endif
	57
	58	/* flag by sched_getattr() */
	59	#if defined(__linux__) && !defined(SCHED_FLAG_RESET_ON_FORK)
	60	# define SCHED_FLAG_RESET_ON_FORK 0x01
0fefbedc AK	61	#endif
0fefbedc AK	62
15167589 KZ	63	#if defined (__linux__) && !defined(HAVE_SCHED_SETATTR)
	64	# include <sys/syscall.h>
	65	#endif
	66
6f27e449 KZ	67	/* usable kernel-headers, but old glibc-headers */
	68	#if defined (__linux__) && !defined(SYS_sched_setattr) && defined(__NR_sched_setattr)
	69	# define SYS_sched_setattr __NR_sched_setattr
	70	#endif
	71
	72	#if defined (__linux__) && !defined(SYS_sched_getattr) && defined(__NR_sched_getattr)
	73	# define SYS_sched_getattr __NR_sched_getattr
	74	#endif
	75
15167589 KZ	76	#if defined (__linux__) && !defined(HAVE_SCHED_SETATTR) && defined(SYS_sched_setattr)
	77	# define HAVE_SCHED_SETATTR
	78
	79	struct sched_attr {
	80	uint32_t size;
	81	uint32_t sched_policy;
	82	uint64_t sched_flags;
	83
	84	/* SCHED_NORMAL, SCHED_BATCH */
	85	int32_t sched_nice;
	86
	87	/* SCHED_FIFO, SCHED_RR */
	88	uint32_t sched_priority;
	89
	90	/* SCHED_DEADLINE (nsec) */
	91	uint64_t sched_runtime;
	92	uint64_t sched_deadline;
	93	uint64_t sched_period;
	94	};
	95
	96	static int sched_setattr(pid_t pid, const struct sched_attr *attr, unsigned int flags)
	97	{
	98	return syscall(SYS_sched_setattr, pid, attr, flags);
	99	}
	100
	101	static int sched_getattr(pid_t pid, struct sched_attr *attr, unsigned int size, unsigned int flags)
	102	{
	103	return syscall(SYS_sched_getattr, pid, attr, size, flags);
	104	}
1a7e6395 KZ	105	#endif
	106
	107	/* the SCHED_DEADLINE is supported since Linux 3.14
	108	* commit id aab03e05e8f7e26f51dee792beddcb5cca9215a5
	109	* -- sched_setattr() is required for this policy!
	110	*/
	111	#if defined (__linux__) && !defined(SCHED_DEADLINE) && defined(HAVE_SCHED_SETATTR)
	112	# define SCHED_DEADLINE 6
	113	#endif
15167589	114
7a4ea566 KZ	115	/* control struct */
	116	struct chrt_ctl {
	117	pid_t pid;
	118	int policy; /* SCHED_* */
	119	int priority;
	120
1a7e6395 KZ	121	uint64_t runtime; /* --sched-* options */
	122	uint64_t deadline;
	123	uint64_t period;
	124
7a4ea566 KZ	125	unsigned int all_tasks : 1, /* all threads of the PID */
7a4ea566 KZ	126	reset_on_fork : 1, /* SCHED_RESET_ON_FORK */
a30cf650	127	altered : 1, /* sched_set*() used /
7a4ea566 KZ	128	verbose : 1; /* verbose output */
7a4ea566 KZ	129	};
0fefbedc	130
5118d1be	131	static void __attribute__((__noreturn__)) usage(void)
48d7b13a	132	{
5118d1be	133	FILE *out = stdout;
aaf6349f	134
451dbcfa	135	fputs(_("Show or change the real-time scheduling attributes of a process.\n"), out);
9acbe2aa BS	136	fputs(USAGE_SEPARATOR, out);
	137	fputs(_("Set policy:\n"
	138	" chrt [options] <priority> <command> [<arg>...]\n"
a6fec537	139	" chrt [options] --pid <priority> <pid>\n"), out);
9acbe2aa BS	140	fputs(USAGE_SEPARATOR, out);
	141	fputs(_("Get policy:\n"
	142	" chrt [options] -p <pid>\n"), out);
aaf6349f	143
9acbe2aa BS	144	fputs(USAGE_SEPARATOR, out);
	145	fputs(_("Policy options:\n"), out);
	146	fputs(_(" -b, --batch set policy to SCHED_BATCH\n"), out);
1a7e6395	147	fputs(_(" -d, --deadline set policy to SCHED_DEADLINE\n"), out);
9acbe2aa BS	148	fputs(_(" -f, --fifo set policy to SCHED_FIFO\n"), out);
	149	fputs(_(" -i, --idle set policy to SCHED_IDLE\n"), out);
	150	fputs(_(" -o, --other set policy to SCHED_OTHER\n"), out);
	151	fputs(_(" -r, --rr set policy to SCHED_RR (default)\n"), out);
aaf6349f	152
9acbe2aa	153	fputs(USAGE_SEPARATOR, out);
1a7e6395 KZ	154	fputs(_("Scheduling options:\n"), out);
	155	fputs(_(" -R, --reset-on-fork set SCHED_RESET_ON_FORK for FIFO or RR\n"), out);
	156	fputs(_(" -T, --sched-runtime <ns> runtime parameter for DEADLINE\n"), out);
	157	fputs(_(" -P, --sched-period <ns> period parameter for DEADLINE\n"), out);
	158	fputs(_(" -D, --sched-deadline <ns> deadline parameter for DEADLINE\n"), out);
	159
9acbe2aa BS	160	fputs(USAGE_SEPARATOR, out);
	161	fputs(_("Other options:\n"), out);
	162	fputs(_(" -a, --all-tasks operate on all the tasks (threads) for a given pid\n"), out);
	163	fputs(_(" -m, --max show min and max valid priorities\n"), out);
	164	fputs(_(" -p, --pid operate on existing given pid\n"), out);
	165	fputs(_(" -v, --verbose display status information\n"), out);
	166
	167	fputs(USAGE_SEPARATOR, out);
f45f3ec3	168	printf(USAGE_HELP_OPTIONS(22));
bd9d9f05	169
f45f3ec3	170	printf(USAGE_MAN_TAIL("chrt(1)"));
5118d1be	171	exit(EXIT_SUCCESS);
48d7b13a KZ	172	}
48d7b13a KZ	173
acde3a05	174	static const char *get_policy_name(int policy)
48d7b13a	175	{
48d7b13a KZ	176	switch (policy) {
48d7b13a KZ	177	case SCHED_OTHER:
acde3a05	178	return "SCHED_OTHER";
48d7b13a	179	case SCHED_FIFO:
a03eac52	180	#ifdef SCHED_RESET_ON_FORK
110d680a	181	case SCHED_FIFO \| SCHED_RESET_ON_FORK:
a03eac52	182	#endif
acde3a05	183	return "SCHED_FIFO";
b64279da	184	#ifdef SCHED_IDLE
c779d6e9	185	case SCHED_IDLE:
acde3a05	186	return "SCHED_IDLE";
b64279da	187	#endif
48d7b13a	188	case SCHED_RR:
a03eac52	189	#ifdef SCHED_RESET_ON_FORK
59e4a382	190	case SCHED_RR \| SCHED_RESET_ON_FORK:
a03eac52	191	#endif
acde3a05	192	return "SCHED_RR";
b64279da	193	#ifdef SCHED_BATCH
df3773fb	194	case SCHED_BATCH:
acde3a05	195	return "SCHED_BATCH";
1a7e6395 KZ	196	#endif
	197	#ifdef SCHED_DEADLINE
	198	case SCHED_DEADLINE:
acde3a05	199	return "SCHED_DEADLINE";
b64279da	200	#endif
48d7b13a	201	default:
acde3a05	202	break;
48d7b13a KZ	203	}
48d7b13a KZ	204
acde3a05 KZ	205	return _("unknown");
	206	}
	207
	208	static void show_sched_pid_info(struct chrt_ctl *ctl, pid_t pid)
	209	{
685f5449	210	int policy = -1, reset_on_fork = 0, prio = 0;
acde3a05 KZ	211	#ifdef SCHED_DEADLINE
	212	uint64_t deadline = 0, runtime = 0, period = 0;
	213	#endif
	214
	215	/* don't display "pid 0" as that is confusing */
	216	if (!pid)
	217	pid = getpid();
	218
6f27e449 KZ	219	errno = 0;
	220
	221	/*
	222	* New way
	223	*/
acde3a05 KZ	224	#ifdef HAVE_SCHED_SETATTR
	225	{
	226	struct sched_attr sa;
	227
6f27e449 KZ	228	if (sched_getattr(pid, &sa, sizeof(sa), 0) != 0) {
	229	if (errno == ENOSYS)
	230	goto fallback;
acde3a05	231	err(EXIT_FAILURE, _("failed to get pid %d's policy"), pid);
6f27e449	232	}
acde3a05 KZ	233
	234	policy = sa.sched_policy;
	235	prio = sa.sched_priority;
	236	reset_on_fork = sa.sched_flags & SCHED_FLAG_RESET_ON_FORK;
	237	deadline = sa.sched_deadline;
	238	runtime = sa.sched_runtime;
	239	period = sa.sched_period;
	240	}
6f27e449 KZ	241
	242	/*
	243	* Old way
	244	*/
	245	fallback:
fded05ac RM	246	if (errno == ENOSYS)
	247	#endif
	248	{
acde3a05 KZ	249	struct sched_param sp;
	250
	251	policy = sched_getscheduler(pid);
	252	if (policy == -1)
	253	err(EXIT_FAILURE, _("failed to get pid %d's policy"), pid);
	254
	255	if (sched_getparam(pid, &sp) != 0)
	256	err(EXIT_FAILURE, _("failed to get pid %d's attributes"), pid);
	257	else
	258	prio = sp.sched_priority;
	259	# ifdef SCHED_RESET_ON_FORK
	260	if (policy == (SCHED_FIFO\|SCHED_RESET_ON_FORK) \|\| policy == (SCHED_BATCH\|SCHED_RESET_ON_FORK))
	261	reset_on_fork = 1;
	262	# endif
	263	}
48d7b13a	264
a30cf650	265	if (ctl->altered)
acde3a05	266	printf(_("pid %d's new scheduling policy: %s"), pid, get_policy_name(policy));
a9a3e5f2	267	else
acde3a05 KZ	268	printf(_("pid %d's current scheduling policy: %s"), pid, get_policy_name(policy));
	269
	270	if (reset_on_fork)
	271	printf("\|SCHED_RESET_ON_FORK");
	272	putchar('\n');
	273
	274	if (ctl->altered)
	275	printf(_("pid %d's new scheduling priority: %d\n"), pid, prio);
	276	else
	277	printf(_("pid %d's current scheduling priority: %d\n"), pid, prio);
	278
	279	#ifdef SCHED_DEADLINE
	280	if (policy == SCHED_DEADLINE) {
	281	if (ctl->altered)
	282	printf(_("pid %d's new runtime/deadline/period parameters: %ju/%ju/%ju\n"),
	283	pid, runtime, deadline, period);
	284	else
	285	printf(_("pid %d's current runtime/deadline/period parameters: %ju/%ju/%ju\n"),
	286	pid, runtime, deadline, period);
	287	}
	288	#endif
48d7b13a KZ	289	}
48d7b13a KZ	290
a30cf650 KZ	291
	292	static void show_sched_info(struct chrt_ctl *ctl)
	293	{
	294	if (ctl->all_tasks) {
	295	pid_t tid;
	296	struct proc_tasks *ts = proc_open_tasks(ctl->pid);
	297
	298	if (!ts)
	299	err(EXIT_FAILURE, _("cannot obtain the list of tasks"));
	300
	301	while (!proc_next_tid(ts, &tid))
	302	show_sched_pid_info(ctl, tid);
	303
	304	proc_close_tasks(ts);
	305	} else
	306	show_sched_pid_info(ctl, ctl->pid);
	307	}
	308
48d7b13a KZ	309	static void show_min_max(void)
48d7b13a KZ	310	{
90b7d261	311	unsigned long i;
110d680a SK	312	int policies[] = {
	313	SCHED_OTHER,
	314	SCHED_FIFO,
	315	SCHED_RR,
b64279da	316	#ifdef SCHED_BATCH
110d680a	317	SCHED_BATCH,
b64279da AJ	318	#endif
b64279da AJ	319	#ifdef SCHED_IDLE
110d680a	320	SCHED_IDLE,
1a7e6395 KZ	321	#endif
	322	#ifdef SCHED_DEADLINE
	323	SCHED_DEADLINE,
b64279da	324	#endif
110d680a	325	};
bd9d9f05 KZ	326
bd9d9f05 KZ	327	for (i = 0; i < ARRAY_SIZE(policies); i++) {
acde3a05 KZ	328	int plc = policies[i];
	329	int max = sched_get_priority_max(plc);
	330	int min = sched_get_priority_min(plc);
bd9d9f05 KZ	331
bd9d9f05 KZ	332	if (max >= 0 && min >= 0)
078720a7	333	printf(_("%s min/max priority\t: %d/%d\n"),
acde3a05	334	get_policy_name(plc), min, max);
bd9d9f05	335	else
078720a7	336	printf(_("%s not supported?\n"), get_policy_name(plc));
bd9d9f05	337	}
48d7b13a KZ	338	}
48d7b13a KZ	339
6f27e449	340	static int set_sched_one_by_setscheduler(struct chrt_ctl *ctl, pid_t pid)
4820a737 KZ	341	{
4820a737 KZ	342	struct sched_param sp = { .sched_priority = ctl->priority };
15167589	343	int policy = ctl->policy;
4820a737	344
88b60f0b	345	errno = 0;
15167589 KZ	346	# ifdef SCHED_RESET_ON_FORK
	347	if (ctl->reset_on_fork)
	348	policy \|= SCHED_RESET_ON_FORK;
	349	# endif
	350	return sched_setscheduler(pid, policy, &sp);
	351	}
	352
6f27e449 KZ	353
	354	#ifndef HAVE_SCHED_SETATTR
	355	static int set_sched_one(struct chrt_ctl *ctl, pid_t pid)
	356	{
	357	return set_sched_one_by_setscheduler(ctl, pid);
	358	}
	359
15167589 KZ	360	#else /* !HAVE_SCHED_SETATTR */
	361	static int set_sched_one(struct chrt_ctl *ctl, pid_t pid)
	362	{
88b60f0b KZ	363	struct sched_attr sa = { .size = sizeof(struct sched_attr) };
	364
	365	/* old API is good enough for non-deadline */
	366	if (ctl->policy != SCHED_DEADLINE)
	367	return set_sched_one_by_setscheduler(ctl, pid);
	368
	369	/* no changeed by chrt, follow the current setting */
	370	sa.sched_nice = getpriority(PRIO_PROCESS, pid);
	371
1a7e6395	372	/* use main() to check if the setting makes sense */
88b60f0b KZ	373	sa.sched_policy = ctl->policy;
	374	sa.sched_priority = ctl->priority;
	375	sa.sched_runtime = ctl->runtime;
	376	sa.sched_period = ctl->period;
	377	sa.sched_deadline = ctl->deadline;
6f27e449	378
15167589 KZ	379	# ifdef SCHED_RESET_ON_FORK
	380	if (ctl->reset_on_fork)
	381	sa.sched_flags \|= SCHED_RESET_ON_FORK;
	382	# endif
6f27e449	383	errno = 0;
88b60f0b	384	return sched_setattr(pid, &sa, 0);
15167589 KZ	385	}
	386	#endif /* HAVE_SCHED_SETATTR */
	387
	388	static void set_sched(struct chrt_ctl *ctl)
	389	{
4820a737 KZ	390	if (ctl->all_tasks) {
	391	pid_t tid;
	392	struct proc_tasks *ts = proc_open_tasks(ctl->pid);
	393
	394	if (!ts)
	395	err(EXIT_FAILURE, _("cannot obtain the list of tasks"));
	396
	397	while (!proc_next_tid(ts, &tid))
15167589	398	if (set_sched_one(ctl, tid) == -1)
4820a737 KZ	399	err(EXIT_FAILURE, _("failed to set tid %d's policy"), tid);
	400
	401	proc_close_tasks(ts);
	402
15167589	403	} else if (set_sched_one(ctl, ctl->pid) == -1)
4820a737 KZ	404	err(EXIT_FAILURE, _("failed to set pid %d's policy"), ctl->pid);
	405
	406	ctl->altered = 1;
	407	}
	408
110d680a	409	int main(int argc, char **argv)
48d7b13a	410	{
c7adc2f2	411	struct chrt_ctl _ctl = { .pid = -1, .policy = SCHED_RR }, *ctl = &_ctl;
4820a737	412	int c;
48d7b13a	413
6c7d5ae9	414	static const struct option longopts[] = {
1a7e6395 KZ	415	{ "all-tasks", no_argument, NULL, 'a' },
	416	{ "batch", no_argument, NULL, 'b' },
	417	{ "deadline", no_argument, NULL, 'd' },
	418	{ "fifo", no_argument, NULL, 'f' },
	419	{ "idle", no_argument, NULL, 'i' },
	420	{ "pid", no_argument, NULL, 'p' },
	421	{ "help", no_argument, NULL, 'h' },
	422	{ "max", no_argument, NULL, 'm' },
	423	{ "other", no_argument, NULL, 'o' },
	424	{ "rr", no_argument, NULL, 'r' },
	425	{ "sched-runtime", required_argument, NULL, 'T' },
	426	{ "sched-period", required_argument, NULL, 'P' },
	427	{ "sched-deadline", required_argument, NULL, 'D' },
	428	{ "reset-on-fork", no_argument, NULL, 'R' },
	429	{ "verbose", no_argument, NULL, 'v' },
	430	{ "version", no_argument, NULL, 'V' },
	431	{ NULL, no_argument, NULL, 0 }
48d7b13a KZ	432	};
48d7b13a KZ	433
bd9d9f05 KZ	434	setlocale(LC_ALL, "");
	435	bindtextdomain(PACKAGE, LOCALEDIR);
	436	textdomain(PACKAGE);
2c308875	437	close_stdout_atexit();
bd9d9f05	438
b3a50671	439	while((c = getopt_long(argc, argv, "+abdD:fiphmoP:T:rRvV", longopts, NULL)) != -1)
48d7b13a	440	{
4820a737	441	switch (c) {
78904e76	442	case 'a':
7a4ea566	443	ctl->all_tasks = 1;
78904e76	444	break;
df3773fb	445	case 'b':
b64279da	446	#ifdef SCHED_BATCH
7a4ea566	447	ctl->policy = SCHED_BATCH;
1a7e6395 KZ	448	#endif
	449	break;
	450
	451	case 'd':
	452	#ifdef SCHED_DEADLINE
	453	ctl->policy = SCHED_DEADLINE;
b64279da	454	#endif
df3773fb	455	break;
48d7b13a	456	case 'f':
7a4ea566	457	ctl->policy = SCHED_FIFO;
48d7b13a	458	break;
cdfb1e88	459	case 'R':
7a4ea566	460	ctl->reset_on_fork = 1;
c150589f	461	break;
c779d6e9	462	case 'i':
b64279da	463	#ifdef SCHED_IDLE
7a4ea566	464	ctl->policy = SCHED_IDLE;
b64279da	465	#endif
c779d6e9	466	break;
48d7b13a KZ	467	case 'm':
48d7b13a KZ	468	show_min_max();
110d680a	469	return EXIT_SUCCESS;
48d7b13a	470	case 'o':
7a4ea566	471	ctl->policy = SCHED_OTHER;
48d7b13a KZ	472	break;
	473	case 'p':
	474	errno = 0;
7a4ea566	475	ctl->pid = strtos32_or_err(argv[argc - 1], _("invalid PID argument"));
48d7b13a KZ	476	break;
48d7b13a KZ	477	case 'r':
7a4ea566	478	ctl->policy = SCHED_RR;
48d7b13a KZ	479	break;
48d7b13a KZ	480	case 'v':
7a4ea566	481	ctl->verbose = 1;
48d7b13a	482	break;
1a7e6395 KZ	483	case 'T':
	484	ctl->runtime = strtou64_or_err(optarg, _("invalid runtime argument"));
	485	break;
	486	case 'P':
	487	ctl->period = strtou64_or_err(optarg, _("invalid period argument"));
	488	break;
	489	case 'D':
	490	ctl->deadline = strtou64_or_err(optarg, _("invalid deadline argument"));
	491	break;
2c308875	492
48d7b13a	493	case 'V':
2c308875	494	print_version(EXIT_SUCCESS);
48d7b13a	495	case 'h':
5118d1be	496	usage();
48d7b13a	497	default:
677ec86c	498	errtryhelp(EXIT_FAILURE);
48d7b13a	499	}
48d7b13a KZ	500	}
48d7b13a KZ	501
7a4ea566	502	if (((ctl->pid > -1) && argc - optind < 1) \|\|
5118d1be RM	503	((ctl->pid == -1) && argc - optind < 2)) {
	504	warnx(_("bad usage"));
	505	errtryhelp(EXIT_FAILURE);
	506	}
48d7b13a	507
7a4ea566	508	if ((ctl->pid > -1) && (ctl->verbose \|\| argc - optind == 1)) {
a30cf650	509	show_sched_info(ctl);
48d7b13a	510	if (argc - optind == 1)
bd9d9f05	511	return EXIT_SUCCESS;
48d7b13a KZ	512	}
	513
	514	errno = 0;
7a4ea566	515	ctl->priority = strtos32_or_err(argv[optind], _("invalid priority argument"));
48d7b13a	516
4951f9b3	517	#ifdef SCHED_RESET_ON_FORK
1a7e6395 KZ	518	if (ctl->reset_on_fork && ctl->policy != SCHED_FIFO && ctl->policy != SCHED_RR)
	519	errx(EXIT_FAILURE, _("--reset-on-fork option is supported for "
	520	"SCHED_FIFO and SCHED_RR policies only"));
	521	#endif
	522	#ifdef SCHED_DEADLINE
	523	if ((ctl->runtime \|\| ctl->deadline \|\| ctl->period) && ctl->policy != SCHED_DEADLINE)
	524	errx(EXIT_FAILURE, _("--sched-{runtime,deadline,period} options "
	525	"are supported for SCHED_DEADLINE only"));
	526	if (ctl->policy == SCHED_DEADLINE) {
	527	/* The basic rule is runtime <= deadline <= period, so we can
	528	* make deadline and runtime optional on command line. Note we
	529	* don't check any values or set any defaults, it's kernel
	530	* responsibility.
	531	*/
	532	if (ctl->deadline == 0)
	533	ctl->deadline = ctl->period;
	534	if (ctl->runtime == 0)
	535	ctl->runtime = ctl->deadline;
	536	}
	537	#else
	538	if (ctl->runtime \|\| ctl->deadline \|\| ctl->period)
	539	errx(EXIT_FAILURE, _("SCHED_DEADLINE is unsupported"));
4951f9b3	540	#endif
7a4ea566 KZ	541	if (ctl->pid == -1)
7a4ea566 KZ	542	ctl->pid = 0;
2e31d1c3 SK	543	if (ctl->priority < sched_get_priority_min(ctl->policy) \|\|
	544	sched_get_priority_max(ctl->policy) < ctl->priority)
	545	errx(EXIT_FAILURE,
	546	_("unsupported priority value for the policy: %d: see --max for valid range"),
	547	ctl->priority);
4820a737	548	set_sched(ctl);
a30cf650	549
7a4ea566	550	if (ctl->verbose)
a30cf650	551	show_sched_info(ctl);
48d7b13a	552
7a4ea566	553	if (!ctl->pid) {
48d7b13a KZ	554	argv += optind + 1;
48d7b13a KZ	555	execvp(argv[0], argv);
61b62222	556	errexec(argv[0]);
48d7b13a KZ	557	}
48d7b13a KZ	558
bd9d9f05	559	return EXIT_SUCCESS;
48d7b13a	560	}