/* vi: set sw=4 ts=4: */
/*
* taskset - retrieve or set a processes' CPU affinity
- * Copyright (c) 2006 Bernhard Fischer
+ * Copyright (c) 2006 Bernhard Reutner-Fischer
*
- * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
+ * Licensed under GPLv2 or later, see file LICENSE in this source tree.
+ */
+
+//config:config TASKSET
+//config: bool "taskset"
+//config: default n # doesn't build on some non-x86 targets (m68k)
+//config: help
+//config: Retrieve or set a processes's CPU affinity.
+//config: This requires sched_{g,s}etaffinity support in your libc.
+//config:
+//config:config FEATURE_TASKSET_FANCY
+//config: bool "Fancy output"
+//config: default y
+//config: depends on TASKSET
+//config: help
+//config: Add code for fancy output. This merely silences a compiler-warning
+//config: and adds about 135 Bytes. May be needed for machines with alot
+//config: of CPUs.
+
+//applet:IF_TASKSET(APPLET(taskset, BB_DIR_USR_BIN, BB_SUID_DROP))
+//kbuild:lib-$(CONFIG_TASKSET) += taskset.o
+
+//usage:#define taskset_trivial_usage
+//usage: "[-p] [MASK] [PID | PROG ARGS]"
+//usage:#define taskset_full_usage "\n\n"
+//usage: "Set or get CPU affinity\n"
+//usage: "\n -p Operate on an existing PID"
+//usage:
+//usage:#define taskset_example_usage
+//usage: "$ taskset 0x7 ./dgemm_test&\n"
+//usage: "$ taskset -p 0x1 $!\n"
+//usage: "pid 4790's current affinity mask: 7\n"
+//usage: "pid 4790's new affinity mask: 1\n"
+//usage: "$ taskset 0x7 /bin/sh -c './taskset -p 0x1 $$'\n"
+//usage: "pid 6671's current affinity mask: 1\n"
+//usage: "pid 6671's new affinity mask: 1\n"
+//usage: "$ taskset -p 1\n"
+//usage: "pid 1's current affinity mask: 3\n"
+/*
+ Not yet implemented:
+ * -a/--all-tasks (affect all threads)
+ * -c/--cpu-list (specify CPUs via "1,3,5-7")
*/
#include <sched.h>
-#include <getopt.h> /* optind */
#include "libbb.h"
#if ENABLE_FEATURE_TASKSET_FANCY
#define TASKSET_PRINTF_MASK "%s"
-#define from_cpuset(x) __from_cpuset(&x)
/* craft a string from the mask */
-static char *__from_cpuset(cpu_set_t *mask)
+static char *from_cpuset(cpu_set_t *mask)
{
int i;
- char *ret = 0, *str = xzalloc(9);
+ char *ret = NULL;
+ char *str = xzalloc((CPU_SETSIZE / 4) + 1); /* we will leak it */
for (i = CPU_SETSIZE - 4; i >= 0; i -= 4) {
- char val = 0;
+ int val = 0;
int off;
for (off = 0; off <= 3; ++off)
- if (CPU_ISSET(i+off, mask))
- val |= 1<<off;
-
+ if (CPU_ISSET(i + off, mask))
+ val |= 1 << off;
if (!ret && val)
ret = str;
- *str++ = (val-'0'<=9) ? (val+48) : (val+87);
+ *str++ = bb_hexdigits_upcase[val] | 0x20;
}
return ret;
}
#else
-#define TASKSET_PRINTF_MASK "%x"
-/* (void*) cast is for battling gcc: */
-/* "dereferencing type-punned pointer will break strict-aliasing rules" */
-#define from_cpuset(mask) (*(unsigned*)(void*)&(mask))
+#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
-#define OPT_p 1
-int taskset_main(int argc, char** argv);
-int taskset_main(int argc, char** argv)
+int taskset_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
+int taskset_main(int argc UNUSED_PARAM, char **argv)
{
- cpu_set_t mask, new_mask;
+ cpu_set_t mask;
pid_t pid = 0;
- unsigned opt;
- 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 */
- opt = getopt32(argv, "+p:", &p_opt);
+ /* 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 (opt & OPT_p) {
- if (argc == optind+1) { /* -p <aff> <pid> */
- aff = p_opt;
- p_opt = argv[optind];
- }
- argv += optind; /* me -p <arg> */
- pid = xatoul_range(p_opt, 1, ULONG_MAX); /* -p <pid> */
- } else
- aff = *++argv; /* <aff> <cmd...> */
- if (aff) {
- unsigned i = 0;
- unsigned long l = xstrtol_range(aff, 0, 1, LONG_MAX);
-
- CPU_ZERO(&new_mask);
- while (i < CPU_SETSIZE && l >= (1<<i)) {
- if ((1<<i) & l)
- CPU_SET(i, &new_mask);
- ++i;
+ opt_complementary = "-1"; /* at least 1 arg */
+ opt_p = getopt32(argv, "+p");
+ argv += optind;
+
+ 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 (opt & OPT_p) {
+ current_new = "current\0new";
+ if (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_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, state, from_cpuset(mask));
- if (!*argv) /* no new affinity given or we did print already, done. */
+ 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 (opt & OPT_p) {
- state += 8;
- ++argv;
- goto print_aff;
+ /* Affinity was specified, translate it into cpu_set_t */
+ CPU_ZERO(&mask);
+ if (!ENABLE_FEATURE_TASKSET_FANCY) {
+ unsigned i;
+ unsigned long long m;
+
+ /* Do not allow zero mask: */
+ m = xstrtoull_range(aff, 0, 1, ULLONG_MAX);
+ i = 0;
+ do {
+ if (m & 1)
+ CPU_SET(i, &mask);
+ i++;
+ m >>= 1;
+ } while (m != 0);
+ } else {
+ unsigned i;
+ char *last_byte;
+ char *bin;
+ uint8_t bit_in_byte;
+
+ /* Cheap way to get "long enough" buffer */
+ bin = xstrdup(aff);
+
+ if (aff[0] != '0' || (aff[1]|0x20) != 'x') {
+/* TODO: decimal/octal masks are still limited to 2^64 */
+ unsigned long long m = xstrtoull_range(aff, 0, 1, ULLONG_MAX);
+ bin += strlen(bin);
+ last_byte = bin - 1;
+ while (m) {
+ *--bin = m & 0xff;
+ m >>= 8;
+ }
+ } else {
+ /* aff is "0x.....", we accept very long masks in this form */
+ last_byte = hex2bin(bin, aff + 2, INT_MAX);
+ if (!last_byte) {
+ bad_aff:
+ bb_error_msg_and_die("bad affinity '%s'", aff);
+ }
+ last_byte--; /* now points to the last byte */
+ }
+
+ i = 0;
+ bit_in_byte = 1;
+ while (last_byte >= bin) {
+ if (bit_in_byte & *last_byte) {
+ if (i >= CPU_SETSIZE)
+ goto bad_aff;
+ CPU_SET(i, &mask);
+ //bb_error_msg("bit %d set", i);
+ }
+ i++;
+ /* bit_in_byte is uint8_t! & 0xff is implied */
+ bit_in_byte = (bit_in_byte << 1);
+ if (!bit_in_byte) {
+ bit_in_byte = 1;
+ last_byte--;
+ }
+ }
}
- ++argv;
- BB_EXECVP(*argv, argv);
- bb_simple_perror_msg_and_die(*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[0]) /* "-p <aff> <pid> [...ignored...]" */
+ goto print_aff; /* print new affinity and exit */
+
+ BB_EXECVP_or_die(argv);
}
-#undef OPT_p
-#undef TASKSET_PRINTF_MASK
-#undef from_cpuset
projects / oweals / busybox.git / blobdiff