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authorGravatar Denys Vlasenko <vda.linux@googlemail.com>2014-08-17 19:36:22 +0200
committerGravatar Denys Vlasenko <vda.linux@googlemail.com>2014-08-17 19:36:22 +0200
commit962c4e822012a6d4c83b869eb47506881b4abc57 (patch)
tree6f23eaa2b896bcb65d081014682b564ffc0dd6fe /miscutils/taskset.c
parentfb8d1ef2d00db013eae3cc675fc8b34fd0a7a987 (diff)
downloadbusybox-962c4e822012a6d4c83b869eb47506881b4abc57.tar.gz
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taskset: support CPU masks for more than 64 CPUs
function old new delta taskset_main 522 631 +109 Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
Diffstat (limited to 'miscutils/taskset.c')
-rw-r--r--miscutils/taskset.c86
1 files changed, 79 insertions, 7 deletions
diff --git a/miscutils/taskset.c b/miscutils/taskset.c
index 4a9e3230d..8bd32ed61 100644
--- a/miscutils/taskset.c
+++ b/miscutils/taskset.c
@@ -6,6 +6,25 @@
* 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-$(CONFIG_TASKSET) += taskset.o
+
//usage:#define taskset_trivial_usage
//usage: "[-p] [MASK] [PID | PROG ARGS]"
//usage:#define taskset_full_usage "\n\n"
@@ -22,6 +41,11 @@
//usage: "pid 6671's new affinity mask: 1\n"
//usage: "$ 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 "libbb.h"
@@ -128,17 +152,65 @@ int taskset_main(int argc UNUSED_PARAM, char **argv)
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);
- enum { CNT_BIT = CPU_SETSIZE < sizeof(m)*8 ? CPU_SETSIZE : sizeof(m)*8 };
+ 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 */
+ }
- CPU_ZERO(&mask);
- for (i = 0; i < CNT_BIT; i++) {
- unsigned long long bit = (1ULL << i);
- if (bit & m)
+ 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--;
+ }
}
}