/* vi: set sw=4 ts=4: */
/*
- * taskset - retrieve or set a processes's CPU affinity
- * Copyright (c) 2006 Bernhard Fischer
+ * taskset - retrieve or set a processes' CPU affinity
+ * Copyright (c) 2006 Bernhard Reutner-Fischer
*
* Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
*/
-#include "busybox.h"
#include <sched.h>
-#include <unistd.h>
-#include <getopt.h> /* optind */
+#include "libbb.h"
-int taskset_main(int argc, char** argv)
+#if ENABLE_FEATURE_TASKSET_FANCY
+#define TASKSET_PRINTF_MASK "%s"
+/* craft a string from the mask */
+static char *from_cpuset(cpu_set_t *mask)
{
- cpu_set_t mask, new_mask;
+ int i;
+ char *ret = NULL;
+ char *str = xzalloc((CPU_SETSIZE / 4) + 1); /* we will leak it */
+
+ for (i = CPU_SETSIZE - 4; i >= 0; i -= 4) {
+ int val = 0;
+ int off;
+ for (off = 0; off <= 3; ++off)
+ if (CPU_ISSET(i + off, mask))
+ val |= 1 << off;
+ if (!ret && val)
+ ret = str;
+ *str++ = bb_hexdigits_upcase[val] | 0x20;
+ }
+ return ret;
+}
+#else
+#define TASKSET_PRINTF_MASK "%llx"
+static unsigned long long from_cpuset(cpu_set_t *mask)
+{
+ struct BUG_CPU_SETSIZE_is_too_small {
+ char BUG_CPU_SETSIZE_is_too_small[
+ CPU_SETSIZE < sizeof(int) ? -1 : 1];
+ };
+ char *p = (void*)mask;
+
+ /* Take the least significant bits. Careful!
+ * Consider both CPU_SETSIZE=4 and CPU_SETSIZE=1024 cases
+ */
+#if BB_BIG_ENDIAN
+ /* For big endian, it means LAST bits */
+ if (CPU_SETSIZE < sizeof(long))
+ p += CPU_SETSIZE - sizeof(int);
+ else if (CPU_SETSIZE < sizeof(long long))
+ p += CPU_SETSIZE - sizeof(long);
+ else
+ p += CPU_SETSIZE - sizeof(long long);
+#endif
+ if (CPU_SETSIZE < sizeof(long))
+ return *(unsigned*)p;
+ if (CPU_SETSIZE < sizeof(long long))
+ return *(unsigned long*)p;
+ return *(unsigned long long*)p;
+}
+#endif
+
+
+int taskset_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
+int taskset_main(int argc UNUSED_PARAM, char **argv)
+{
+ cpu_set_t mask;
pid_t pid = 0;
- unsigned long ul;
- const char *state = "current\0new";
- char *p_opt = NULL, *aff = NULL;
+ unsigned opt_p;
+ const char *current_new;
+ char *pid_str;
+ char *aff = aff; /* for compiler */
- ul = bb_getopt_ulflags(argc, argv, "+p:", &p_opt);
-#define TASKSET_OPT_p (1)
+ /* NB: we mimic util-linux's taskset: -p does not take
+ * an argument, i.e., "-pN" is NOT valid, only "-p N"!
+ * Indeed, util-linux-2.13-pre7 uses:
+ * getopt_long(argc, argv, "+pchV", ...), not "...p:..." */
- if (ul & TASKSET_OPT_p) {
- if (argc == optind+1) { /* -p <aff> <pid> */
- aff = p_opt;
- p_opt = argv[optind];
- }
- argv += optind; /* me -p <arg> */
- pid = bb_xgetularg10_bnd(p_opt, 1, ULONG_MAX); /* -p <pid> */
- } else
- aff = *++argv; /* <aff> <cmd...> */
- if (aff) {
-/* to_cpuset(bb_xgetularg_bnd(aff, 16, 1, ULONG_MAX), &new_mask); */
- unsigned i = 0;
- unsigned long l = bb_xgetularg_bnd(aff, 16, 1, ULONG_MAX);
+ opt_complementary = "-1"; /* at least 1 arg */
+ opt_p = getopt32(argv, "+p");
+ argv += optind;
- CPU_ZERO(&new_mask);
- while (i < CPU_SETSIZE && l >= (1<<i)) {
- if ((1<<i) & l)
- CPU_SET(i, &new_mask);
- ++i;
+ if (opt_p) {
+ pid_str = *argv++;
+ if (*argv) { /* "-p <aff> <pid> ...rest.is.ignored..." */
+ aff = pid_str;
+ pid_str = *argv; /* NB: *argv != NULL in this case */
}
+ /* else it was just "-p <pid>", and *argv == NULL */
+ pid = xatoul_range(pid_str, 1, ((unsigned)(pid_t)ULONG_MAX) >> 1);
+ } else {
+ aff = *argv++; /* <aff> <cmd...> */
+ if (!*argv)
+ bb_show_usage();
}
- if (ul & TASKSET_OPT_p) {
-print_aff:
- if (sched_getaffinity(pid, sizeof (mask), &mask) < 0)
- bb_perror_msg_and_die("Failed to %cet pid %d's affinity", 'g', pid);
- bb_printf("pid %d's %s affinity mask: %x\n", /* %x .. perhaps _FANCY */
- pid, state, mask);
- if (!*argv) /* no new affinity given or we did print already, done. */
+ current_new = "current\0new";
+ if (opt_p) {
+ print_aff:
+ if (sched_getaffinity(pid, sizeof(mask), &mask) < 0)
+ bb_perror_msg_and_die("can't %cet pid %d's affinity", 'g', pid);
+ printf("pid %d's %s affinity mask: "TASKSET_PRINTF_MASK"\n",
+ pid, current_new, from_cpuset(&mask));
+ if (!*argv) {
+ /* Either it was just "-p <pid>",
+ * or it was "-p <aff> <pid>" and we came here
+ * for the second time (see goto below) */
return EXIT_SUCCESS;
+ }
+ *argv = NULL;
+ current_new += 8; /* "new" */
}
- if (sched_setaffinity(pid, sizeof (new_mask), &new_mask))
- bb_perror_msg_and_die("Failed to %cet pid %d's affinity", 's', pid);
- if (ul & TASKSET_OPT_p) {
- state += 8;
- ++argv;
- goto print_aff;
+ { /* Affinity was specified, translate it into cpu_set_t */
+ unsigned i;
+ /* Do not allow zero mask: */
+ unsigned long long m = xstrtoull_range(aff, 0, 1, ULLONG_MAX);
+ enum { CNT_BIT = CPU_SETSIZE < sizeof(m)*8 ? CPU_SETSIZE : sizeof(m)*8 };
+
+ CPU_ZERO(&mask);
+ for (i = 0; i < CNT_BIT; i++) {
+ unsigned long long bit = (1ULL << i);
+ if (bit & m)
+ CPU_SET(i, &mask);
+ }
}
- ++argv;
- execvp(*argv, argv);
- bb_perror_msg_and_die("%s", *argv);
+
+ /* Set pid's or our own (pid==0) affinity */
+ if (sched_setaffinity(pid, sizeof(mask), &mask))
+ bb_perror_msg_and_die("can't %cet pid %d's affinity", 's', pid);
+
+ if (!*argv) /* "-p <aff> <pid> [...ignored...]" */
+ goto print_aff; /* print new affinity and exit */
+
+ BB_EXECVP(*argv, argv);
+ bb_simple_perror_msg_and_die(*argv);
}