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-rw-r--r--schedutils/taskset.c334
1 files changed, 334 insertions, 0 deletions
diff --git a/schedutils/taskset.c b/schedutils/taskset.c
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+++ b/schedutils/taskset.c
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+/*
+ * taskset.c - taskset
+ * Command-line utility for setting and retrieving a task's CPU affinity
+ *
+ * Robert Love <rml@tech9.net> 25 April 2002
+ *
+ * Linux kernels as of 2.5.8 provide the needed syscalls for
+ * working with a task's cpu affinity. Currently 2.4 does not
+ * support these syscalls, but patches are available at:
+ *
+ * http://www.kernel.org/pub/linux/kernel/people/rml/cpu-affinity/
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License, v2, 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., 675 Mass Ave, Cambridge, MA 02139, USA.
+ *
+ * Copyright (C) 2004 Robert Love
+ */
+
+#define _GNU_SOURCE
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <getopt.h>
+#include <sched.h>
+#include <errno.h>
+#include <string.h>
+#include <ctype.h>
+
+static void show_usage(const char *cmd)
+{
+ fprintf(stderr, "taskset version " VERSION "\n");
+ fprintf(stderr, "usage: %s [options] [mask | cpu-list] [pid |"\
+ " cmd [args...]]\n", cmd);
+ fprintf(stderr, "set or get the affinity of a process\n\n");
+ fprintf(stderr, " -p, --pid "
+ "operate on existing given pid\n");
+ fprintf(stderr, " -c, --cpu-list "\
+ "display and specify cpus in list format\n");
+ fprintf(stderr, " -h, --help display this help\n");
+ fprintf(stderr, " -v, --version "\
+ "output version information\n\n");
+ fprintf(stderr, "The default behavior is to run a new command:\n");
+ fprintf(stderr, " %s 03 sshd -b 1024\n", cmd);
+ fprintf(stderr, "You can retrieve the mask of an existing task:\n");
+ fprintf(stderr, " %s -p 700\n", cmd);
+ fprintf(stderr, "Or set it:\n");
+ fprintf(stderr, " %s -p 03 700\n", cmd);
+ fprintf(stderr, "List format uses a comma-separated list instead"\
+ " of a mask:\n");
+ fprintf(stderr, " %s -pc 0,3,7-11 700\n", cmd);
+ fprintf(stderr, "Ranges in list format can take a stride argument:\n");
+ fprintf(stderr, " e.g. 0-31:2 is equivalent to mask 0x55555555\n\n");
+}
+
+static inline int val_to_char(int v)
+{
+ if (v >= 0 && v < 10)
+ return '0' + v;
+ else if (v >= 10 && v < 16)
+ return ('a' - 10) + v;
+ else
+ return -1;
+}
+
+static char * cpuset_to_str(cpu_set_t *mask, char *str)
+{
+ int base;
+ char *ptr = str;
+ char *ret = 0;
+
+ for (base = CPU_SETSIZE - 4; base >= 0; base -= 4) {
+ char val = 0;
+ if (CPU_ISSET(base, mask))
+ val |= 1;
+ if (CPU_ISSET(base + 1, mask))
+ val |= 2;
+ if (CPU_ISSET(base + 2, mask))
+ val |= 4;
+ if (CPU_ISSET(base + 3, mask))
+ val |= 8;
+ if (!ret && val)
+ ret = ptr;
+ *ptr++ = val_to_char(val);
+ }
+ *ptr = 0;
+ return ret ? ret : ptr - 1;
+}
+
+static char * cpuset_to_cstr(cpu_set_t *mask, char *str)
+{
+ int i;
+ char *ptr = str;
+ int entry_made = 0;
+
+ for (i = 0; i < CPU_SETSIZE; i++) {
+ if (CPU_ISSET(i, mask)) {
+ int j;
+ int run = 0;
+ entry_made = 1;
+ for (j = i + 1; j < CPU_SETSIZE; j++) {
+ if (CPU_ISSET(j, mask))
+ run++;
+ else
+ break;
+ }
+ if (!run)
+ sprintf(ptr, "%d,", i);
+ else if (run == 1) {
+ sprintf(ptr, "%d,%d,", i, i + 1);
+ i++;
+ } else {
+ sprintf(ptr, "%d-%d,", i, i + run);
+ i += run;
+ }
+ while (*ptr != 0)
+ ptr++;
+ }
+ }
+ ptr -= entry_made;
+ *ptr = 0;
+
+ return str;
+}
+
+static inline int char_to_val(int c)
+{
+ int cl;
+
+ cl = tolower(c);
+ if (c >= '0' && c <= '9')
+ return c - '0';
+ else if (cl >= 'a' && cl <= 'f')
+ return cl + (10 - 'a');
+ else
+ return -1;
+}
+
+static int str_to_cpuset(cpu_set_t *mask, const char* str)
+{
+ int len = strlen(str);
+ const char *ptr = str + len - 1;
+ int base = 0;
+
+ /* skip 0x, it's all hex anyway */
+ if (len > 1 && !memcmp(str, "0x", 2L))
+ str += 2;
+
+ CPU_ZERO(mask);
+ while (ptr >= str) {
+ char val = char_to_val(*ptr);
+ if (val == (char) -1)
+ return -1;
+ if (val & 1)
+ CPU_SET(base, mask);
+ if (val & 2)
+ CPU_SET(base + 1, mask);
+ if (val & 4)
+ CPU_SET(base + 2, mask);
+ if (val & 8)
+ CPU_SET(base + 3, mask);
+ len--;
+ ptr--;
+ base += 4;
+ }
+
+ return 0;
+}
+
+static const char *nexttoken(const char *q, int sep)
+{
+ if (q)
+ q = strchr(q, sep);
+ if (q)
+ q++;
+ return q;
+}
+
+static int cstr_to_cpuset(cpu_set_t *mask, const char* str)
+{
+ const char *p, *q;
+ q = str;
+ CPU_ZERO(mask);
+
+ while (p = q, q = nexttoken(q, ','), p) {
+ unsigned int a; /* beginning of range */
+ unsigned int b; /* end of range */
+ unsigned int s; /* stride */
+ const char *c1, *c2;
+
+ if (sscanf(p, "%u", &a) < 1)
+ return 1;
+ b = a;
+ s = 1;
+
+ c1 = nexttoken(p, '-');
+ c2 = nexttoken(p, ',');
+ if (c1 != NULL && (c2 == NULL || c1 < c2)) {
+ if (sscanf(c1, "%u", &b) < 1)
+ return 1;
+ c1 = nexttoken(c1, ':');
+ if (c1 != NULL && (c2 == NULL || c1 < c2))
+ if (sscanf(c1, "%u", &s) < 1) {
+ return 1;
+ }
+ }
+
+ if (!(a <= b))
+ return 1;
+ while (a <= b) {
+ CPU_SET(a, mask);
+ a += s;
+ }
+ }
+
+ return 0;
+}
+
+int main(int argc, char *argv[])
+{
+ cpu_set_t new_mask, cur_mask;
+ pid_t pid = 0;
+ int opt, err;
+ char mstr[1 + CPU_SETSIZE / 4];
+ char cstr[7 * CPU_SETSIZE];
+ int c_opt = 0;
+
+ struct option longopts[] = {
+ { "pid", 0, NULL, 'p' },
+ { "cpu-list", 0, NULL, 'c' },
+ { "help", 0, NULL, 'h' },
+ { "version", 0, NULL, 'V' },
+ { NULL, 0, NULL, 0 }
+ };
+
+ while ((opt = getopt_long(argc, argv, "+pchV", longopts, NULL)) != -1) {
+ int ret = 1;
+
+ switch (opt) {
+ case 'p':
+ pid = atoi(argv[argc - 1]);
+ break;
+ case 'c':
+ c_opt = 1;
+ break;
+ case 'V':
+ printf("taskset version " VERSION "\n");
+ return 0;
+ case 'h':
+ ret = 0;
+ default:
+ show_usage(argv[0]);
+ return ret;
+ }
+ }
+
+ if ((!pid && argc - optind < 2)
+ || (pid && (argc - optind < 1 || argc - optind > 2))) {
+ show_usage(argv[0]);
+ return 1;
+ }
+
+ if (pid) {
+ if (sched_getaffinity(pid, sizeof (cur_mask), &cur_mask) < 0) {
+ perror("sched_getaffinity");
+ fprintf(stderr, "failed to get pid %d's affinity\n",
+ pid);
+ return 1;
+ }
+ if (c_opt)
+ printf("pid %d's current affinity list: %s\n", pid,
+ cpuset_to_cstr(&cur_mask, cstr));
+ else
+ printf("pid %d's current affinity mask: %s\n", pid,
+ cpuset_to_str(&cur_mask, mstr));
+
+ if (argc - optind == 1)
+ return 0;
+ }
+
+ if (c_opt)
+ err = cstr_to_cpuset(&new_mask, argv[optind]);
+ else
+ err = str_to_cpuset(&new_mask, argv[optind]);
+
+ if (err) {
+ if (c_opt)
+ fprintf(stderr, "failed to parse CPU list %s\n",
+ argv[optind]);
+ else
+ fprintf(stderr, "failed to parse CPU mask %s\n",
+ argv[optind]);
+ return 1;
+ }
+
+ if (sched_setaffinity(pid, sizeof (new_mask), &new_mask)) {
+ perror("sched_setaffinity");
+ fprintf(stderr, "failed to set pid %d's affinity.\n", pid);
+ return 1;
+ }
+
+ if (sched_getaffinity(pid, sizeof (cur_mask), &cur_mask) < 0) {
+ perror("sched_getaffinity");
+ fprintf(stderr, "failed to get pid %d's affinity.\n", pid);
+ return 1;
+ }
+
+ if (pid) {
+ if (c_opt)
+ printf("pid %d's new affinity list: %s\n", pid,
+ cpuset_to_cstr(&cur_mask, cstr));
+ else
+ printf("pid %d's new affinity mask: %s\n", pid,
+ cpuset_to_str(&cur_mask, mstr));
+ } else {
+ argv += optind + 1;
+ execvp(argv[0], argv);
+ perror("execvp");
+ fprintf(stderr, "failed to execute %s\n", argv[0]);
+ return 1;
+ }
+
+ return 0;
+}
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