/* 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)
+{
+ char *p = (void*)mask;
+
+ BUILD_BUG_ON(CPU_SETSIZE < sizeof(int));
+
+ /* 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 ATTRIBUTE_UNUSED, char **argv)
+int taskset_main(int argc UNUSED_PARAM, char **argv)
{
cpu_set_t mask;
pid_t pid = 0;
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));
+ pid, current_new, from_cpuset(&mask));
if (!*argv) {
/* Either it was just "-p <pid>",
* or it was "-p <aff> <pid>" and we came here
current_new += 8; /* "new" */
}
- { /* Affinity was specified, translate it into cpu_set_t */
+ /* 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: */
- unsigned long long m = xstrtoull_range(aff, 0, 1, ULLONG_MAX);
- CPU_ZERO(&mask);
- for (i = 0; i < CPU_SETSIZE; i++) {
- unsigned long long bit = (1ULL << i);
- if (bit & m)
+ 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--;
+ }
}
}
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...]" */
+ if (!
argv[0]) /* "-p <aff> <pid> [...ignored...]" */
goto print_aff; /* print new affinity and exit */
- BB_EXECVP(*argv, argv);
- bb_simple_perror_msg_and_die(*argv);
+ BB_EXECVP_or_die(argv);
}
projects / oweals / busybox.git / blobdiff