.\" man2/sched_setaffinity.2 - sched_setaffinity and sched_getaffinity man page
.\"
.\" Copyright (C) 2002 Robert Love
.\" and Copyright (C) 2006 Michael Kerrisk
.\"
.\" This is free documentation; you can redistribute it and/or
.\" modify it under the terms of the GNU General Public License as
.\" published by the Free Software Foundation; either version 2 of
.\" the License, or (at your option) any later version.
.\"
.\" The GNU General Public License's references to "object code"
.\" and "executables" are to be interpreted as the output of any
.\" document formatting or typesetting system, including
.\" intermediate and printed output.
.\"
.\" This manual is distributed in the hope that it will be useful,
.\" but WITHOUT ANY WARRANTY; without even the implied warranty of
.\" MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
.\" GNU General Public License for more details.
.\"
.\" You should have received a copy of the GNU General Public
.\" License along with this manual; if not, write to the Free
.\" Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111,
.\" USA.
.\"
.\" 2002-11-19 Robert Love <rml@tech9.net> - initial version
.\" 2004-04-20 mtk - fixed description of return value
.\" 2004-04-22 aeb - added glibc prototype history
.\" 2005-05-03 mtk - noted that sched_setaffinity may cause thread
.\"	migration and that CPU affinity is a per-thread attribute.
.\" 2006-02-03 mtk -- Major rewrite
.\" 2008-11-12, mtk, removed CPU_*() macro descriptions to a
.\" separate CPU_SET(3) page.
.\"
.\" Japanese Version Copyright (c) 2003, 2005 Yuichi SATO
.\"         all rights reserved.
.\" Translated 2003-01-23, Yuichi SATO <ysato444@yahoo.co.jp>
.\" Updated & Modified 2003-09-23, Yuichi SATO
.\" Updated & Modified 2005-01-03, Yuichi SATO
.\" Updated & Modified 2005-09-13, Akihiro MOTOKI <amotoki@dd.iij4u.or.jp>
.\" Updated & Modified 2006-07-14, Akihiro MOTOKI, LDP v2.34
.\" Updated & Modified 2008-12-24, Akihiro MOTOKI, LDP v3.14
.\"
.\"WORD:	affinity		
.\"WORD:	most significant bit	Ǿ̥ӥå
.\"WORD:	least significant bit	Dz̥ӥå
.\"WORD:	capability		
.\"
.TH SCHED_SETAFFINITY 2 2008-11-14 "Linux" "Linux Programmer's Manual"
.SH ̾
sched_setaffinity, sched_getaffinity \- \
ץ CPU affinity ޥꡦ
.SH 
.nf
.B #define _GNU_SOURCE
.B #include <sched.h>
.sp
.BI "int sched_setaffinity(pid_t " pid ", size_t " cpusetsize ,
.BI "                      cpu_set_t *" mask );
.sp
.BI "int sched_getaffinity(pid_t " pid ", size_t " cpusetsize ,
.BI "                      cpu_set_t *" mask );
.fi
.SH 
ץ CPU affinity () ޥϡΥץ
¹ԤĤƤ CPU νꤹ롣
ޥץåƥǤϡCPU affinity ޥꤹ뤳Ȥ
ǽΥåȤǽ롣
㤨СΥץĤ CPU ˳դ
(ʤΥץ affinity ޥĤ CPU ꤷ)
¾ƤΥץ affinity ޥ餽 CPU 뤳Ȥǡ
μ¤ˤΥץμ¹®٤ˤ뤳ȤǤ롣
ޤץμ¹ԤĤ CPU ˸ꤹ뤳Ȥǡ
Ĥ CPU Ǥμ¹ԤߤƤ̤ CPU Ǽ¹ԤƳȤȯ
å̵ (cache invalidation) ˤǽ̤򤱤뤳ȤǤ롣

CPU affinity ޥϡCPU νפɽ
.I cpu_set_t
¤Τɽ졢
.I cpu_set_t
ؤΥݥ
.I mask
ǻꤵ롣
CPU 뤿ΥޥˤĤƤ
.BR CPU_SET (3)
ǵܤƤ롣

.BR sched_setaffinity ()
ϡץID 
.I pid
Υץ CPU affinity ޥ
.I mask
ǻꤵ줿ͤꤹ롣
.I pid
 0 ξ硢ƤӽФץȤ롣
.I cpusetsize
ˤ
.I mask
ؤǡĹ (Хñ) Ǥ롣
̾ϡΰˤ
.I "sizeof(cpu_set_t)"
ꤹФ褤

.I pid
ǻꤵ줿ץ
.I mask
ǻꤵ줿 CPU Τ줫Ǹ߼¹ԤƤʤ硢
Υץ
.I mask
ǻꤵ줿 CPU Τ줫˰ư롣

.BR sched_getaffinity ()
ϡ
ץID 
.I pid
Υץ affinity ޥ
.I mask
ؤ
.I cpu_set_t
¤Τ˽񤭹ࡣ
.I cpusetsize
ˤ
.I mask
 (Хñ̤) 礭ꤹ롣

ؿ
.BR sched_getaffinity ()
Ĺ
.I len
Υݥ
.I mask
˥ץ
.I pid
 affinity ޥ񤭹ࡣ
.I pid
 0 ξ硢ƤӽФΥץΥޥ֤롣
.SH ֤
硢
.BR sched_setaffinity ()

.BR sched_getaffinity ()
 0 ֤
顼ξ \-1 ֤
.I errno
Ŭڤꤹ롣
.SH 顼
.TP
.B EFAULT
ꤵ줿ϤǤ롣
.TP
.B EINVAL
ƥ˸߼ºݤ¸ߤ
"cpuset" ݤ¤ˤƤΥץФƵĤƤ
ץå
affinity ӥåȥޥ
.I mask
˴ޤޤƤʤ
"cpuset" ˤĤƤ
.BR cpuset (7)
򻲾ȡ
.TP
.B EINVAL
.RB ( sched_getaffinity ()
ȡͥ 2.6.9 
.BR sched_setaffinity ())
.I cpusetsize
ͥǻȤƤ affinity ޥΥ꾮
.TP
.B EPERM
.RB ( sched_setaffinity ())
ƤӽФΥץŬڤøʤä
ƤӽФϡ¸桼 ID 
.I pid
Ǽ̤ץΥ桼 ID ޤϼ¸桼 ID ƱǤ뤫
.B CAP_SYS_NICE
ѥӥƥ (capability) ʤФʤʤ
.TP
.B ESRCH
ץ ID \fIpid\fP ΥץĤʤä
.SH С
CPU affinity ƥॳ Linux kernel 2.5.8 Ƴ줿
ΥƥॳΥåѡؿ glibc 2.3 Ƴ줿
ǽϡglibc Υ󥿥եˤ
.I "unsigned int"

.I cpusetsize
äƤ
glibc 2.3.3 Ǥ
.I cpusetsize
줿glibc 2.3.4 
.I size_t
褷
.SH 
Υƥॳ Linux ͭǤ롣
.SH 
.BR sched_setaffinity ()
ƤӽФϡץºݤ˼¹Ԥ CPU νϡ
.I mask
ǻꤵ줿ȡƥ˼ºݤ¸ߤ CPU ν
̽ (AND) Ȥʤ롣
"cpuset" ѤƤˤϡץư CPU 
ФƥƥϤ¤ä뤫⤷ʤ
("cpuset" ˤĤƤ
.BR cpuset (7)
򻲾)
ץưºݤ CPU Ф¤ϥͥˤ
ۤΤŬѤ롣

.BR sched_setscheduler (2)
ˤ Linux ˤ륹塼󥰵ˤĤƤ롣
.PP
ºݤˤ affinity ޥϥåñ̤°ǡåɥ롼פ
ƥåñ̤ΩĴ뤳ȤǤ롣
.BR gettid (2)
뤫֤ͤ򤳤Υ
.I pid
ȤϤȤǤ롣
.I pid
 0 ꤹȸƤӽФΥåɤ°ꤵ졢
.BR getpid (2)
뤫֤ͤ
.I pid
˻ꤹȥåɥ롼פΥᥤ󥹥åɤ°ꤵ
(POSIX å API ѤƤ硢
.BR sched_setaffinity ()

.BR pthread_setaffinity_np (3)
Ѥ뤳)

.BR fork (2)
ͳ줿ҥץϿƥץ CPU affinity ޥѾ롣
affinity ޥ
.BR execve (2)
¸롣

Υޥ˥奢ڡǤ CPU affinity  glibc 󥿥ե
Ƥ롣ºݤΥƥॳ롦󥿥եϾäƤꡢ
ºݤμǤ CPU ϴñʥӥåȥޥǤȤ¾ȿǤ
.I mask
η
.IR "unsigned long *"
ȤʤäƤ롣
ˤϡ
.BR sched_getaffinity ()
ƥॳ뼫Ȥ
.I cpumask_t
ǡ (Хñ̤) 礭֤
.I cpumask_t
ϥͥ CPU ΥӥåȥޥɽΤ
ȤƤǡǤ롣
.SH Ϣ
.BR clone (2),
.BR getcpu (2),
.BR getpriority (2),
.BR gettid (2),
.BR nice (2),
.BR sched_get_priority_max (2),
.BR sched_get_priority_min (2),
.BR sched_getscheduler (2),
.BR sched_setscheduler (2),
.BR setpriority (2),
.BR pthread_setaffinity_np (3),
.BR CPU_SET (3),
.BR sched_getcpu (3),
.BR capabilities (7),
.BR cpuset (7)