emo/busybox
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

taskset: support CPU masks for more than 64 CPUs

Browse Source 
function                                             old     new   delta
taskset_main                                         522     631    +109

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
This commit is contained in:
Denys Vlasenko 2014-08-17 19:36:22 +02:00
parent fb8d1ef2d0
commit 962c4e8220
4 changed files with 80 additions and 26 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

1
include/applets.src.h
View File

@ -342,7 +342,6 @@ IF_BB_SYSCTL(APPLET(sysctl, BB_DIR_SBIN, BB_SUID_DROP))
IF_SYSLOGD(APPLET(syslogd, BB_DIR_SBIN, BB_SUID_DROP))
IF_TAC(APPLET_NOEXEC(tac, tac, BB_DIR_USR_BIN, BB_SUID_DROP, tac))
IF_TAIL(APPLET(tail, BB_DIR_USR_BIN, BB_SUID_DROP))
IF_TASKSET(APPLET(taskset, BB_DIR_USR_BIN, BB_SUID_DROP))
/* IF_TC(APPLET(tc, BB_DIR_SBIN, BB_SUID_DROP)) */
IF_TCPSVD(APPLET_ODDNAME(tcpsvd, tcpudpsvd, BB_DIR_USR_BIN, BB_SUID_DROP, tcpsvd))
IF_TEE(APPLET(tee, BB_DIR_USR_BIN, BB_SUID_DROP))

16
miscutils/Config.src
View File

@ -499,22 +499,6 @@ config STRINGS
strings prints the printable character sequences for each file
specified.
config TASKSET
bool "taskset"
default n # doesn't build on some non-x86 targets (m68k)
help
Retrieve or set a processes's CPU affinity.
This requires sched_{g,s}etaffinity support in your libc.
config FEATURE_TASKSET_FANCY
bool "Fancy output"
default y
depends on TASKSET
help
Add code for fancy output. This merely silences a compiler-warning
and adds about 135 Bytes. May be needed for machines with alot
of CPUs.
config TIME
bool "time"
default y

1
miscutils/Kbuild.src
View File

@ -39,7 +39,6 @@ lib-$(CONFIG_RUNLEVEL) += runlevel.o
lib-$(CONFIG_RX) += rx.o
lib-$(CONFIG_SETSID) += setsid.o
lib-$(CONFIG_STRINGS) += strings.o
lib-$(CONFIG_TASKSET) += taskset.o
lib-$(CONFIG_TIME) += time.o
lib-$(CONFIG_TIMEOUT) += timeout.o
lib-$(CONFIG_TTYSIZE) += ttysize.o

90
miscutils/taskset.c
View File

@ -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 */
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 };
/* Affinity was specified, translate it into cpu_set_t */
CPU_ZERO(&mask);
for (i = 0; i < CNT_BIT; i++) {
unsigned long long bit = (1ULL << i);
if (bit & m)
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--;
}
}
}