From cfe5e3905201349e9cf3f95d52ff4bd100bde37d Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Sun, 14 Apr 2024 21:10:49 +0200 Subject: Adding upstream version 2.39.3. Signed-off-by: Daniel Baumann --- schedutils/chrt.c | 493 ++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 493 insertions(+) create mode 100644 schedutils/chrt.c (limited to 'schedutils/chrt.c') diff --git a/schedutils/chrt.c b/schedutils/chrt.c new file mode 100644 index 0000000..250d878 --- /dev/null +++ b/schedutils/chrt.c @@ -0,0 +1,493 @@ +/* + * chrt.c - manipulate a task's real-time attributes + * + * 27-Apr-2002: initial version - Robert Love + * 04-May-2011: make it thread-aware - Davidlohr Bueso + * + * 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 +#include +#include +#include +#include +#include +#include +#include + +#include "c.h" +#include "nls.h" +#include "closestream.h" +#include "strutils.h" +#include "procfs.h" +#include "sched_attr.h" + + +/* 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 or SCHED_FLAG_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] [...]\n" + " chrt [options] --pid \n"), out); + fputs(USAGE_SEPARATOR, out); + fputs(_("Get policy:\n" + " chrt [options] -p \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 reset-on-fork flag\n"), out); + fputs(_(" -T, --sched-runtime runtime parameter for DEADLINE\n"), out); + fputs(_(" -P, --sched-period period parameter for DEADLINE\n"), out); + fputs(_(" -D, --sched-deadline 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) +{ +#ifdef SCHED_RESET_ON_FORK + policy &= ~SCHED_RESET_ON_FORK; +#endif + switch (policy) { + case SCHED_OTHER: + return "SCHED_OTHER"; + case SCHED_FIFO: + return "SCHED_FIFO"; +#ifdef SCHED_IDLE + case SCHED_IDLE: + return "SCHED_IDLE"; +#endif + case SCHED_RR: + 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_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) { +#ifdef __linux__ + DIR *sub = NULL; + pid_t tid; + struct path_cxt *pc = ul_new_procfs_path(ctl->pid, NULL); + + while (pc && procfs_process_next_tid(pc, &sub, &tid) == 0) + show_sched_pid_info(ctl, tid); + + ul_unref_path(pc); +#else + err(EXIT_FAILURE, _("cannot obtain the list of tasks")); +#endif + } 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 + +#if defined (__linux__) && defined(SYS_sched_setscheduler) + /* musl libc returns ENOSYS for its sched_setscheduler library + * function, because the sched_setscheduler Linux kernel system call + * does not conform to Posix; so we use the system call directly + */ + return syscall(SYS_sched_setscheduler, pid, policy, &sp); +#else + return sched_setscheduler(pid, policy, &sp); +#endif +} + + +#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_FLAG_RESET_ON_FORK + /* Don't use SCHED_RESET_ON_FORK for sched_setattr()! */ + if (ctl->reset_on_fork) + sa.sched_flags |= SCHED_FLAG_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) { +#ifdef __linux__ + DIR *sub = NULL; + pid_t tid; + struct path_cxt *pc = ul_new_procfs_path(ctl->pid, NULL); + + if (!pc) + err(EXIT_FAILURE, _("cannot obtain the list of tasks")); + + while (procfs_process_next_tid(pc, &sub, &tid) == 0) { + if (set_sched_one(ctl, tid) == -1) + err(EXIT_FAILURE, _("failed to set tid %d's policy"), tid); + } + ul_unref_path(pc); +#else + err(EXIT_FAILURE, _("cannot obtain the list of tasks")); +#endif + } 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_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; +} -- cgit v1.2.3