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-rw-r--r--schedutils/taskset.c273
1 files changed, 273 insertions, 0 deletions
diff --git a/schedutils/taskset.c b/schedutils/taskset.c
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--- /dev/null
+++ b/schedutils/taskset.c
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+/*
+ * 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"
+
+#ifndef PF_NO_SETAFFINITY
+# define PF_NO_SETAFFINITY 0x04000000
+#endif
+
+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) {
+ uintmax_t flags = 0;
+ struct path_cxt *pc;
+ int errsv = errno;
+
+ if (errno != EPERM
+ && (pc = ul_new_procfs_path(ts->pid, NULL))
+ && procfs_process_get_stat_nth(pc, 9, &flags) == 0
+ && (flags & PF_NO_SETAFFINITY)) {
+ warnx(_("affinity cannot be set due to PF_NO_SETAFFINITY flag set"));
+ errno = EINVAL;
+ } else
+ errno = errsv;
+
+ 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;
+}
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