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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 14:30:35 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 14:30:35 +0000 |
commit | 378c18e5f024ac5a8aef4cb40d7c9aa9633d144c (patch) | |
tree | 44dfb6ca500d32cabd450649b322a42e70a30683 /schedutils/taskset.c | |
parent | Initial commit. (diff) | |
download | util-linux-378c18e5f024ac5a8aef4cb40d7c9aa9633d144c.tar.xz util-linux-378c18e5f024ac5a8aef4cb40d7c9aa9633d144c.zip |
Adding upstream version 2.38.1.upstream/2.38.1upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'schedutils/taskset.c')
-rw-r--r-- | schedutils/taskset.c | 254 |
1 files changed, 254 insertions, 0 deletions
diff --git a/schedutils/taskset.c b/schedutils/taskset.c new file mode 100644 index 0000000..0ab7d12 --- /dev/null +++ b/schedutils/taskset.c @@ -0,0 +1,254 @@ +/* + * taskset.c - set or retrieve a task's CPU affinity + * + * 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 + * Copyright (C) 2010 Karel Zak <kzak@redhat.com> + */ + +#include <stdio.h> +#include <stdlib.h> +#include <unistd.h> +#include <getopt.h> +#include <errno.h> +#include <sched.h> +#include <stddef.h> +#include <string.h> + +#include "cpuset.h" +#include "nls.h" +#include "strutils.h" +#include "xalloc.h" +#include "procfs.h" +#include "c.h" +#include "closestream.h" + +struct taskset { + pid_t pid; /* task PID */ + cpu_set_t *set; /* task CPU mask */ + size_t setsize; + char *buf; /* buffer for conversion from mask to string */ + size_t buflen; + unsigned int use_list:1, /* use list rather than masks */ + get_only:1; /* print the mask, but not modify */ +}; + +static void __attribute__((__noreturn__)) usage(void) +{ + FILE *out = stdout; + fprintf(out, + _("Usage: %s [options] [mask | cpu-list] [pid|cmd [args...]]\n\n"), + program_invocation_short_name); + + fputs(USAGE_SEPARATOR, out); + fputs(_("Show or change the CPU affinity of a process.\n"), out); + fputs(USAGE_SEPARATOR, out); + + fprintf(out, _( + "Options:\n" + " -a, --all-tasks operate on all the tasks (threads) for a given pid\n" + " -p, --pid operate on existing given pid\n" + " -c, --cpu-list display and specify cpus in list format\n" + )); + printf(USAGE_HELP_OPTIONS(25)); + + fputs(USAGE_SEPARATOR, out); + fprintf(out, _( + "The default behavior is to run a new command:\n" + " %1$s 03 sshd -b 1024\n" + "You can retrieve the mask of an existing task:\n" + " %1$s -p 700\n" + "Or set it:\n" + " %1$s -p 03 700\n" + "List format uses a comma-separated list instead of a mask:\n" + " %1$s -pc 0,3,7-11 700\n" + "Ranges in list format can take a stride argument:\n" + " e.g. 0-31:2 is equivalent to mask 0x55555555\n"), + program_invocation_short_name); + + printf(USAGE_MAN_TAIL("taskset(1)")); + exit(EXIT_SUCCESS); +} + +static void print_affinity(struct taskset *ts, int isnew) +{ + char *str, *msg; + + if (ts->use_list) { + str = cpulist_create(ts->buf, ts->buflen, ts->set, ts->setsize); + msg = isnew ? _("pid %d's new affinity list: %s\n") : + _("pid %d's current affinity list: %s\n"); + } else { + str = cpumask_create(ts->buf, ts->buflen, ts->set, ts->setsize); + msg = isnew ? _("pid %d's new affinity mask: %s\n") : + _("pid %d's current affinity mask: %s\n"); + } + + if (!str) + errx(EXIT_FAILURE, _("internal error: conversion from cpuset to string failed")); + + printf(msg, ts->pid ? ts->pid : getpid(), str); +} + +static void __attribute__((__noreturn__)) err_affinity(pid_t pid, int set) +{ + char *msg; + + msg = set ? _("failed to set pid %d's affinity") : + _("failed to get pid %d's affinity"); + + err(EXIT_FAILURE, msg, pid ? pid : getpid()); +} + +static void do_taskset(struct taskset *ts, size_t setsize, cpu_set_t *set) +{ + /* read the current mask */ + if (ts->pid) { + if (sched_getaffinity(ts->pid, ts->setsize, ts->set) < 0) + err_affinity(ts->pid, 0); + print_affinity(ts, FALSE); + } + + if (ts->get_only) + return; + + /* set new mask */ + if (sched_setaffinity(ts->pid, setsize, set) < 0) + err_affinity(ts->pid, 1); + + /* re-read the current mask */ + if (ts->pid) { + if (sched_getaffinity(ts->pid, ts->setsize, ts->set) < 0) + err_affinity(ts->pid, 0); + print_affinity(ts, TRUE); + } +} + +int main(int argc, char **argv) +{ + cpu_set_t *new_set; + pid_t pid = 0; + int c, all_tasks = 0; + int ncpus; + size_t new_setsize, nbits; + struct taskset ts; + + static const struct option longopts[] = { + { "all-tasks", 0, NULL, 'a' }, + { "pid", 0, NULL, 'p' }, + { "cpu-list", 0, NULL, 'c' }, + { "help", 0, NULL, 'h' }, + { "version", 0, NULL, 'V' }, + { NULL, 0, NULL, 0 } + }; + + setlocale(LC_ALL, ""); + bindtextdomain(PACKAGE, LOCALEDIR); + textdomain(PACKAGE); + close_stdout_atexit(); + + memset(&ts, 0, sizeof(ts)); + + while ((c = getopt_long(argc, argv, "+apchV", longopts, NULL)) != -1) { + switch (c) { + case 'a': + all_tasks = 1; + break; + case 'p': + pid = strtos32_or_err(argv[argc - 1], + _("invalid PID argument")); + break; + case 'c': + ts.use_list = 1; + break; + + case 'V': + print_version(EXIT_SUCCESS); + case 'h': + usage(); + default: + errtryhelp(EXIT_FAILURE); + } + } + + if ((!pid && argc - optind < 2) + || (pid && (argc - optind < 1 || argc - optind > 2))) { + warnx(_("bad usage")); + errtryhelp(EXIT_FAILURE); + } + + ncpus = get_max_number_of_cpus(); + if (ncpus <= 0) + errx(EXIT_FAILURE, _("cannot determine NR_CPUS; aborting")); + + /* + * the ts->set is always used for the sched_getaffinity call + * On the sched_getaffinity the kernel demands a user mask of + * at least the size of its own cpumask_t. + */ + ts.set = cpuset_alloc(ncpus, &ts.setsize, &nbits); + if (!ts.set) + err(EXIT_FAILURE, _("cpuset_alloc failed")); + + /* buffer for conversion from mask to string */ + ts.buflen = 7 * nbits; + ts.buf = xmalloc(ts.buflen); + + /* + * new_set is always used for the sched_setaffinity call + * On the sched_setaffinity the kernel will zero-fill its + * cpumask_t if the user's mask is shorter. + */ + new_set = cpuset_alloc(ncpus, &new_setsize, NULL); + if (!new_set) + err(EXIT_FAILURE, _("cpuset_alloc failed")); + + if (argc - optind == 1) + ts.get_only = 1; + + else if (ts.use_list) { + if (cpulist_parse(argv[optind], new_set, new_setsize, 0)) + errx(EXIT_FAILURE, _("failed to parse CPU list: %s"), + argv[optind]); + } else if (cpumask_parse(argv[optind], new_set, new_setsize)) { + errx(EXIT_FAILURE, _("failed to parse CPU mask: %s"), + argv[optind]); + } + + if (all_tasks && pid) { + DIR *sub = NULL; + struct path_cxt *pc = ul_new_procfs_path(pid, NULL); + + while (pc && procfs_process_next_tid(pc, &sub, &ts.pid) == 0) + do_taskset(&ts, new_setsize, new_set); + + ul_unref_path(pc); + } else { + ts.pid = pid; + do_taskset(&ts, new_setsize, new_set); + } + + free(ts.buf); + cpuset_free(ts.set); + cpuset_free(new_set); + + if (!pid) { + argv += optind + 1; + execvp(argv[0], argv); + errexec(argv[0]); + } + + return EXIT_SUCCESS; +} |