.\" This is _*_ nroff _*_ source. Emacs, gimme all those colors :)
.\"
.\" Copyright (c) International Business Machines orp., 2006
.\"
.\" This program is free software; 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.
.\"
.\" This program 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 program; if not, write to the Free Software
.\" Foundation, Inc., 59 Temple Place, Suite 330, Boston,
.\" MA 02111-1307 USA
.\"
.\" HISTORY:
.\" 2006-04-27, created by Eduardo M. Fleury <efleury@br.ibm.com>
.\" with various additions by Michael Kerrisk <mtk.manpages@gmail.com>
.\"
.\" Japanese Version Copyright (c) 2007 Akihiro MOTOKI
.\"         all rights reserved.
.\" Translated 2007-01-09, Akihiro MOTOKI <amotoki@dd.iij4u.or.jp>, LDP v2.43
.\"
.TH IOPRIO_SET 2 2007-06-01 "Linux" "Linux Programmer's Manual"
.SH ̾
ioprio_get, ioprio_set \- I/O 塼󥰥饹ͥ٤/
.SH 
.nf
.BI "int ioprio_get(int " which ", int " who );
.BI "int ioprio_set(int " which ", int " who ", int " ioprio );
.fi
.SH 
ƥॳ
.BR ioprio_get ()
/
.BR ioprio_set ()
ϡ(1İʾ) ץ I/O 塼󥰥饹
ͥ٤μ/Ԥ

.I which

.I who
ǥƥॳоݤȤʤץؼ롣
.I which
ϡ
.I who
ɤΤ褦˲᤹뤫ΤǡʲΤ줫Ĥꤹ롣
.TP
.B IOPRIO_WHO_PROCESS
.I who
ϥץID Ǥꡢꤵ줿 1 ץоݤȤʤ롣
.TP
.B IOPRIO_WHO_PGRP
.I who
ϥץ롼ID Ǥꡢץ롼פФоݤȤʤ롣
.TP
.B IOPRIO_WHO_USER
.I who
ϥ桼ID Ǥꡢ UID ˰פץоݤȤʤ롣
.PP
.BR ioprio_get ()
θƤӽФ
.I which

.B IOPRIO_WHO_PGRP

.B IOPRIO_WHO_USER
ꤵ졢
.I who
˰פץʣä硢
פץΤǺǤ⤤ͥ٤֤롣
ͥ٤⤤Ȥϡ⤤ͥ٥饹°Ƥ
.RB ( IOPRIO_CLASS_RT
Ǥ⤤ͥ٥饹ǡ
.B IOPRIO_CLASS_IDLE
Ǥ㤤)⤷
Ʊͥ٥饹°Ƥ뤬ͥ٥٥뤬⤤
(ֹͥ椬ͥ٥٥뤬⤤Ȥ̣)
ȤȤǤ롣

.BR ioprio_set ()
Ϥ
.I ioprio
ϡоݤȤʤץ˳Ƥ륹塼󥰥饹
ͥ٤ξꤹӥåȥޥǤ롣
.I ioprio
ͤȤΩƤ᤹ΤˡʲΥޥѤǤ롣
.TP
.BI IOPRIO_PRIO_VALUE( class ", " data )
塼󥰥饹
.I class
ͥ
.RI ( data )
ͿȡΥޥ 2ĤͤȤ߹碌ơ
.I ioprio
ͤޥη̤Ȥ֤
.TP
.BI IOPRIO_PRIO_CLASS( mask )
.I mask
.RI ( ioprio
) ͿȡΥޥ I/O 饹ǡĤޤ
.BR IOPRIO_CLASS_RT ,
.BR IOPRIO_CLASS_BE ,
.B IOPRIO_CLASS_IDLE
Τ줫Ĥ֤ͤ
.TP
.BI IOPRIO_PRIO_DATA( mask )
.I mask
.RI ( ioprio
) ͿȡΥޥͥ
.RI ( data )
Ǥ֤
.PP
塼󥰥饹ͥ٤˴ؤܤϡ
͡פ򻲾ȤΤȡ

I/O ͥ٤ɤ߽ФƱ񤭹
.RB ( O_DIRECT ,
.BR O_SYNC )
бƤ롣
I/O ͥ٤Ʊ񤭹ߤˤбƤʤʤʤ顢
Ʊ񤭹ߤϥ񤭴Ԥץư (context) Ȥ
طʤȯԤ졢Τץñ̤ͥ٤ŬѤʤ
Ǥ롣
.SH ֤
ȡ
.BR ioprio_get ()
ϡ
.I which

.I who
ǻꤵ줿˹פץǺǤ⤤ I/O ͥ٤ĥץ
.I ioprio
֤ͤ
顼ξ硢\-1 ֤
.I errno
˥顼򼨤ͤꤹ롣
.PP
ȡ
.BR ioprio_set ()
 0 ֤
顼ξ硢\-1 ֤
.I errno
˥顼򼨤ͤꤹ롣
.SH 顼
.TP
.B EINVAL
.I which

.I ioprio
ͤǤ롣
.I ioprio
Ѥ˻ǽʥ塼饯饹ͥ٥٥ˤĤƤ
͡פ򻲾ȤΤȡ
.TP
.B EPERM
ƤӽФץꤵ줿ץ
.I ioprio
ƤΤɬפʸ¤äƤʤ
.BR ioprio_set ()
ɬפʸ¤ˤĤƤξܤϡ͡פ򻲾ȤΤȡ
.TP
.B ESRCH
.I which

.I who
ǻꤵ줿˹פץĤʤä
.SH С
Υƥॳϥͥ 2.6.13 ʹߤ Linux ѲǽǤ롣
.SH 
Υƥॳ Linux ȼǤ롣
.SH 
glibc ϤΥƥॳФåѡؿ󶡤Ƥʤ
.BR syscall (2)
ȤäƸƤӽФȡ

ΥƥॳϡI/O ͥ٤б I/O 塼
Ȥ߹碌ƻѤ줿ˤΤ߸̤ġ
ͥ 2.6.17 Ǥϡξ塼
Completely Fair Queuing (CFQ) I/O 塼Ǥ롣
.SS I/O 塼
I/O 塼ϥǥХñ̤˹Ԥ졢
ڥե
.I /sys/block/<device>/queue/scheduler
ͳǹԤ롣

ߤ I/O 塼
.I /sys
ե륷ƥͳǻȤǤ롣㤨СʲΥޥɤ¹Ԥȡ
ߥͥǥɤƤ륹塼ꥹȤɽ롣
.sp
.RS
.nf
$ cat /sys/block/hda/queue/scheduler
noop anticipatory deadline [cfq]
.fi
.RE
.sp
̤ǰϤޤ줿塼餬ΥǥХ (Ǥ
.IR hda )
ˤĤƼºݤ˻ѤƤ륹塼Ǥ롣
̤Υ塼ꤹˤϡΥե˿塼̾
񤭹Ф褤㤨СʲΥޥɤ¹ԤȡǥХ
.I hda
Υ塼Ȥ
.I cfq
ꤵ롣
.sp
.RS
.nf
$ su
Password:
# echo cfq > /sys/block/hda/queue/scheduler
.fi
.RE
.SS "Completely Fair Queuing (CFQ) I/O 塼"
С 3 (̾ CFQ Time Sliced) ʹߡ
CPU 塼󥰤Ʊͤ I/O nice ٥뤬 CFQ ˼Ƥ롣
 nice ٥ 3ĤΥ塼󥰥饹ʬǤ
ƥ塼󥰥饹ˤĤ 1İʾͥ٥٥뤬Ƥ롣
.TP
.BR IOPRIO_CLASS_RT " (1)"
ϥꥢ륿 I/O 饹Ǥ롣
Υ塼󥰥饹ˤ¾Υ饹⤤ͥ٤Ϳ롣
Υ饹Υץˤϡ˥ǥؤΥͥ褷
Ƥ롣Τᡢ I/O 饹Ȥݤˤϡ
äĤ ꥢ륿 I/O 饹Υץˤ
ƥΤΥǥǤʤʤäƤޤȤ
Ȥˡդʧɬפ롣
Υ饹ˤϡ8 ʳ class data (ͥ٥٥) 롣
ͤϡΥץ 1Υǥˤɤ
֤ɬפΤ˷뤿ΤΤǤ롣
ǹΥꥢ륿ͥ٥٥ 0 ǡ 7 Ǥ롣
Ūˤϡͥ٥٥ϡ˾ǡ졼ȤϤʤɡ
ľŪǽȿǤǤ褦ѹ뤫⤷ʤ
.TP
.BR IOPRIO_CLASS_BE " (2)"
 ٥ȥեȡ塼󥰥饹Ǥ롣
Υ饹ϡ I/O ͥ٤ꤷƤʤץ
ǥեͤǤ롣
class data (ͥ٥٥) ˤꡢΥץɤ٤
I/O Ӱ뤫ꤵ롣
٥ȥեȡͥ٥٥ϡCPU  nice 
.RB ( getpriority (2)
) ƱͤΤΤǤ롣
ͥ٥٥ϡ٥ȥեȡ塼󥰥饹
¾ΥץȤŪͥ٤ꤹ롣
ͥ٥٥ͤϰϤ 0 (ǹ)  7 () Ǥ롣
.TP
.BR IOPRIO_CLASS_IDLE " (3)"
 idle 塼󥰥饹Ǥ롣
Υ٥ưץ¾˥ǥ򤷤褦Ȥ
ץʤˤΤ I/O ֤롣
idle 饹ˤ class data (ͥ) ѰդƤʤ
ץˤͥ٤ƤݤˤդɬפǤ롣
ʤʤ顢ͥ٤ι⤤ץ˥ǥ˥Ƥˤ
ǥ˥Ǥʤʤǽ뤫
.PP
CFQ I/O 塼ιʤȥץץˤĤƤ
.I Documentation/block/ioprio.txt
򻲾ȤΤȡ
.SS "I/O ͥ٤ɬפʵ"
ץͥ٤ѹĤ뤫ɤ
ʲ 2Ĥξ˴𤤤Ʒꤵ롣
.TP
.B "ץνͭ"
øץϡץμ UID ƤӽФץμ UID ⤷
¸ UID Ȱפץ I/O ͥ٤ΤߤǤ롣
.B CAP_SYS_NICE
ѥӥƥĥץϡɤΥץͥ٤ǤѹǤ롣
.TP
.B "ɤͥ٤ꤷ褦ȤƤ뤫"
˹⤤ͥ
.RB ( IOPRIO_CLASS_RT )
㤤ͥ
.RB ( IOPRIO_CLASS_IDLE )
ꤷ褦Ȥ硢
.B CAP_SYS_ADMIN
ѥӥƥɬפǤ롣
.PP
.BR ioprio_set ()
ϤξΥ롼˽ʤ硢顼
.B EPERM
ǼԤ롣
.SH Х
.\" 6 May 07: Bug report raised:
.\" http://sources.redhat.com/bugzilla/show_bug.cgi?id=4464
.\" Ulriich Drepper replied that he wasn't going to add these
.\" to glibc.
glibc ϡΥڡ˵ܤ줿ؿץȥפޥ
Ŭڤʥإåեޤ󶡤Ƥʤ
ɬפˤĤƤ
.I linux/ioprio.h
򸫤Ф褤
.SH Ϣ
.BR getpriority (2),
.BR open (2),
.BR capabilities (7)
.sp
ͥ롦 Documentation/block/ioprio.txt