[linuxjm/LDP_man-pages.git] / release / man2 / posix_fadvise.2

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.\" Copyright 2003 Abhijit Menon-Sen <ams@wiw.org>
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.\" 2005-04-08 mtk, noted kernel version and added BUGS
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.\" Japanese Version Copyright (c) 2004-2007 Yuichi SATO
.\"         all rights reserved.
.\" Translated Sun Jun 20 16:23:17 JST 2004
.\"         by Yuichi SATO <ysato444@yahoo.co.jp>, LDP v1.66
.\" Updated & Modified Fri Apr 22 03:05:51 JST 2005 by Yuichi SATO, LDP v2.02
.\" Updated & Modified Thu Jan  4 23:55:18 JST 2007 by Yuichi SATO, LDP v2.43
.\"
.TH POSIX_FADVISE 2 2003-02-14 "Linux" "Linux Programmer's Manual"
.SH ̾Á°
posix_fadvise \- ¥Õ¥¡¥¤¥ë¥Ç¡¼¥¿¤Î¥¢¥¯¥»¥¹¥Ñ¥¿¡¼¥ó¤ò¤¢¤é¤«¤¸¤áÀë¸À¤¹¤ë
.SH ½ñ¼°
.nf
.B #define _XOPEN_SOURCE 600
.B #include <fcntl.h>
.sp
.BI "int posix_fadvise(int " fd ", off_t " offset ", off_t " len \
", int " advice ");"
.fi
.SH ÀâÌÀ
¥×¥í¥°¥é¥à¤Ï¡¢¾­ÍèÆÃÄê¤Î¥Ñ¥¿¡¼¥ó¤Ç¥Õ¥¡¥¤¥ë¥Ç¡¼¥¿¤Ë
¥¢¥¯¥»¥¹¤¹¤ë°Õ»×¤òÅÁ¤¨¤ë¤¿¤á¤Ë
.BR posix_fadvise ()
¤ò»È¤¦¤³¤È¤¬¤Ç¤­¤ë¡£
¤³¤ì¤Ë¤è¤ê¡¢¥«¡¼¥Í¥ë¤¬Å¬ÀڤʺÇŬ²½¤ò¼Â¹Ô¤¹¤ë¤³¤È¤¬²Äǽ¤Ë¤Ê¤ë¡£

\fIadvice\fP ¤Ï  \fIfd\fP ¤¬»²¾È¤·¤Æ¤¤¤ë¥Õ¥¡¥¤¥ë¤Î
\fIoffset\fP ¤«¤é»Ï¤Þ¤ë \fIlen\fP ¥Ð¥¤¥È¤ÎÈÏ°ÏÆâ
(\fIlen\fP ¤¬ 0 ¤Î¾ì¹ç¤Ï¥Õ¥¡¥¤¥ë¤Î½ª¤ê¤Þ¤Ç) ¤Î
(ɬ¤º¤·¤â¸ºß¤·¤Ê¤¤) Îΰè¤ËŬÍѤµ¤ì¤ë¡£
¥¢¥É¥Ð¥¤¥¹¤ÏµÁ̳¤Å¤±¤Ç¤Ï¤Ê¤¤¡£
¥¢¥É¥Ð¥¤¥¹¤Ïñ¤Ë¥¢¥×¥ê¥±¡¼¥·¥ç¥ó¤Î¤¿¤á¤Ë²ÄǽÀ­¤ò¹½À®¤¹¤ë¤À¤±¤Ç¤¢¤ë¡£

\fIadvice\fP ¤Ëµö¤µ¤ì¤ëÃͤˤϡ¢°Ê²¼¤Î¤â¤Î¤¬´Þ¤Þ¤ì¤ë:
.TP
.B POSIX_FADV_NORMAL
»ØÄꤵ¤ì¤¿¥Ç¡¼¥¿¤Î¥¢¥¯¥»¥¹¥Ñ¥¿¡¼¥ó¤ò»Ø¼¨¤¹¤ë¥¢¥É¥Ð¥¤¥¹¤ò
¥¢¥×¥ê¥±¡¼¥·¥ç¥ó¤¬²¿¤â»ý¤Ã¤Æ¤¤¤Ê¤¤¤³¤È¤ò¼¨¤¹¡£
¥ª¡¼¥×¥ó¤µ¤ì¤¿¥Õ¥¡¥¤¥ë¤Ë¥¢¥É¥Ð¥¤¥¹¤¬»ØÄꤵ¤ì¤Ê¤¤¾ì¹ç¡¢
¤³¤ì¤¬¥Ç¥Õ¥©¥ë¥È¤Ç²¾Äꤵ¤ì¤ë¡£
.TP
.B POSIX_FADV_SEQUENTIAL
¥¢¥×¥ê¥±¡¼¥·¥ç¥ó¤Ï»ØÄꤵ¤ì¤¿¥Ç¡¼¥¿¤¬¥·¡¼¥±¥ó¥·¥ã¥ë¤Ë
(Â礭¤Ê¥ª¥Õ¥»¥Ã¥È¤ÎÁ°¤Ë¾®¤µ¤Ê¥ª¥Õ¥»¥Ã¥È¤Î¥Ç¡¼¥¿¤òÆɤà¤è¤¦¤Ë)
¥¢¥¯¥»¥¹¤µ¤ì¤ë¤³¤È¤ò´üÂÔ¤¹¤ë¡£
.TP
.B POSIX_FADV_RANDOM
»ØÄꤵ¤ì¤¿¥Ç¡¼¥¿¤¬¥é¥ó¥À¥à¤Ê½çÈ֤ǥ¢¥¯¥»¥¹¤µ¤ì¤ë¡£
.TP
.B POSIX_FADV_NOREUSE
»ØÄꤵ¤ì¤¿¥Ç¡¼¥¿¤Ï 1 ÅÙ¤·¤«¥¢¥¯¥»¥¹¤µ¤ì¤Ê¤¤¡£
.TP
.B POSIX_FADV_WILLNEED
»ØÄꤵ¤ì¤¿¥Ç¡¼¥¿¤Ï¶á¤¤¾­Í襢¥¯¥»¥¹¤µ¤ì¤ë¡£
.TP
.B POSIX_FADV_DONTNEED
»ØÄꤵ¤ì¤¿¥Ç¡¼¥¿¤Ï¶á¤¤¾­Í襢¥¯¥»¥¹¤µ¤ì¤Ê¤¤¡£
.SH ÊÖ¤êÃÍ
À®¸ù¤·¤¿¾ì¹ç¤Ï 0 ¤¬ÊÖ¤µ¤ì¤ë¡£
¼ºÇÔ¤·¤¿¾ì¹ç¤Ï¥¨¥é¡¼Èֹ椬ÊÖ¤µ¤ì¤ë¡£
.SH ¥¨¥é¡¼
.TP
.B EBADF
\fIfd\fP °ú¤­¿ô¤¬Í­¸ú¤Ê¥Õ¥¡¥¤¥ë¥Ç¥£¥¹¥¯¥ê¥×¥¿¤Ç¤Ê¤¤¡£
.TP
.B EINVAL
̵¸ú¤ÊÃͤ¬ \fIadvice\fP ¤Ë»ØÄꤵ¤ì¤¿¡£
.TP
.B ESPIPE
»ØÄꤵ¤ì¤¿¥Õ¥¡¥¤¥ë¥Ç¥£¥¹¥¯¥ê¥×¥¿¤¬¥Ñ¥¤¥×¤Þ¤¿¤Ï FIFO ¤ò»²¾È¤·¤Æ¤¤¤ë
(¤³¤Î¾ì¹ç¡¢Linux ¤Ï¼ÂºÝ¤Ë¤Ï
.B EINVAL
¤òÊÖ¤¹)¡£
.SH ¥Ð¡¼¥¸¥ç¥ó
.BR posix_fadvise ()
¤Ï¥«¡¼¥Í¥ë 2.5.60 ¤ÇÅо줷¤¿¡£
.\" ¼ÂºÝ¤Ë¤Ï fadvise64() ¤È¤·¤ÆÅо줷¤¿¡£-- MTK
glibc ¤Ç¤Î¥µ¥Ý¡¼¥È¤Ï glibc ¥Ð¡¼¥¸¥ç¥ó 2.2 °Ê¹ß¤Ç¹Ô¤ï¤ì¤Æ¤¤¤ë¡£
.SH ½àµò
POSIX.1-2001.
.I len
°ú¤­¿ô¤Î·¿¤¬ POSIX.1-2003 TC1 ¤Ë¤ª¤¤¤Æ
.I size_t
¤«¤é
.I off_t
¤ËÊѹ¹¤µ¤ì¤¿ÅÀ¤ËÃí°Õ¤¹¤ë¤³¤È¡£
.SH Ãí°Õ
Linux ¤Ç¤Ï¡¢\fBPOSIX_FADV_NORMAL\fP ¤Ï¥Ð¥Ã¥­¥ó¥°¥Ç¥Ð¥¤¥¹¤Î
¥Ç¥Õ¥©¥ë¥È¥µ¥¤¥º¤ËÀèÆÉ¤ß (readahead) ¥¦¥¤¥ó¥É¥¦¤òÀßÄꤹ¤ë¡£
\fBPOSIX_FADV_SEQUENTIAL\fP ¤Ï¤³¤Î¥µ¥¤¥º¤ò 2 Çܤ·¡¢
\fBPOSIX_FADV_RANDOM\fP ¤ÏÀèÆɤߤòÁ´¤¯Ìµ¸ú¤Ë¤¹¤ë¡£
¤³¤ì¤é¤ÎÊѹ¹¤Ï¥Õ¥¡¥¤¥ëÁ´ÂΤ˱ƶÁ¤·¡¢»ØÄꤵ¤ì¤¿Îΰè¤Î¤ß¤Ë±Æ¶Á¤¹¤ë¤ï¤±¤Ç¤Ï¤Ê¤¤
(¤·¤«¤·Æ±¤¸¥Õ¥¡¥¤¥ë¤ËÂФ¹¤ë¾¤Î¥ª¡¼¥×¥ó¥Õ¥¡¥¤¥ë¥Ï¥ó¥É¥ë¤Ï±Æ¶Á¤ò¼õ¤±¤Ê¤¤)¡£

\fBPOSIX_FADV_WILLNEED\fP ¤Ï¡¢
¥Ú¡¼¥¸¥­¥ã¥Ã¥·¥å¤Ë»ØÄêÎΰè¤Î¥Ö¥í¥Ã¥¯¤µ¤ì¤Ê¤¤Æɤ߹þ¤ß¤ò³«»Ï¤¹¤ë¡£
Æɤ߹þ¤Þ¤ì¤ë¥Ç¡¼¥¿¤ÎÁíÎ̤ϡ¢
²¾ÁÛ¥á¥â¥ê¤ÎÉé²Ù¤Ë°Í¤Ã¤Æ¥«¡¼¥Í¥ë¤¬¸º¤é¤¹¤«¤â¤·¤ì¤Ê¤¤
(¿ô¥á¥¬¥Ð¥¤¥È¤Ç¤¢¤ì¤ÐÄ̾ï¤ÏÁ´¤¯½½Ê¬¤Ç¤¢¤ê¡¢
¤½¤ì¤è¤ê¿¤¯¤Æ¤â¤á¤Ã¤¿¤ËÌò¤ËΩ¤¿¤Ê¤¤)¡£

2.6.18 ¤è¤êÁ°¤Î¥«¡¼¥Í¥ë¤Ç¤Ï¡¢\fBPOSIX_FADV_NOREUSE\fP ¤Ï
\fBPOSIX_FADV_WILLNEED\fP ¤ÈƱ¤¸°ÕÌ£¤Ç¤¢¤Ã¤¿¡£
¤³¤ì¤Ï¿ʬ¥Ð¥°¤Ç¤¢¤Ã¤¿¡£
¥«¡¼¥Í¥ë 2.6.18 °Ê¹ß¤Ç¤Ï¡¢¤³¤Î¥Õ¥é¥°¤Ï²¿¤â¹Ô¤ï¤Ê¤¤¡£

\fBPOSIX_FADV_DONTNEED\fP ¤Ï»ØÄꤵ¤ì¤¿Îΰè¤Ë´ØÏ¢ÉÕ¤±¤é¤ì¤¿
¥­¥ã¥Ã¥·¥å¥Ú¡¼¥¸¤ò²òÊü¤·¤è¤¦¤È¤¹¤ë¡£
Î㤨¤Ð¡¢¤³¤ì¤ÏÂ礭¤Ê¥Õ¥¡¥¤¥ë¤ò¥¹¥È¥ê¡¼¥ß¥ó¥°¤¹¤ë¤È¤­¤ËÌòΩ¤Ä¡£
¥×¥í¥°¥é¥à¤Ï¡¢»ÈÍѺѤߤΥ­¥ã¥Ã¥·¥å¤µ¤ì¤¿¥Ç¡¼¥¿¤ò²òÊü¤¹¤ë¤è¤¦¤Ë¡¢
Äê´üŪ¤Ë¥«¡¼¥Í¥ë¤ËÍ׵᤹¤ë¤«¤â¤·¤ì¤Ê¤¤¡£
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¤½¤Î¥Ú¡¼¥¸¤Î²òÊü¤¬Êݾڤµ¤ì¤ë¤³¤È¤ò¥¢¥×¥ê¥±¡¼¥·¥ç¥ó¤¬Ë¾¤ó¤Ç¤¤¤ë¤Ê¤é¡¢
ºÇ½é¤Ë
.BR fsync (2)
¤Þ¤¿¤Ï
.BR fdatasync (2)
¤ò¸Æ¤Ö¤Ù¤­¤Ç¤¢¤ë¡£
.SH ¥Ð¥°
2.6.6 ¤è¤êÁ°¤Î¥«¡¼¥Í¥ë¤Ç¤Ï¡¢
.I len
¤Ë 0 ¤¬»ØÄꤵ¤ì¤¿¾ì¹ç¡¢
¡Ö¥Õ¥¡¥¤¥ë¤Î½ª¤ê¤Þ¤Ç¤ÎÁ´¤Æ¤Î¥Ð¥¤¥È¡×¤È¤¤¤¦°ÕÌ£¤Ç¤Ï¤Ê¤¯¡¢
ʸ»úÄ̤ê¡Ö0 ¥Ð¥¤¥È¡×¤È¤·¤Æ²ò¼á¤µ¤ì¤Æ¤¤¤¿¡£
.SH ´ØÏ¢¹àÌÜ
.BR readahead (2),
.BR posix_fallocate (3),
.BR posix_madvise (3),
.\" FIXME . Write a posix_fadvise(3) page.
.BR feature_test_macros (7)