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Date: Sun, 12 Nov 2000 20:36:38 +0900
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From: Motomichi Matsuzaki <mzaki@e-mail.ne.jp>
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In-Reply-To: In your message of "Sun, 12 Nov 2000 17:57:13 +0900"
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$B>>:j$G$9!#(B

At Sun, 12 Nov 2000 17:57:13 +0900,
NOKUBI Hirotaka <nokubi@ff.iij4u.or.jp> wrote:
> $B!d(B This is an efficient way of allowing malloc(3) to free pages
> $B!d(B anywhere in the address space, while keeping the address space valid.
> $B$H$"$C$F!"$I!<$b6u4V$O(B valid $B$G%a%b%j$@$12rJ|$G$-$k$h$&$KFI$a$^$9!#(B
> $B$H$$$&$+!"C1$K$$$i$J$$$H$$$&$@$1$J$i$o$6$o$6(B MADV_FREE $B$H$+8@$&I,MW$O(B
> $BL5$/$F(B sbrk(2) $B$G6u4V$r=L$a$l$PNI$$(B? $B$=$l$O=E$$$+$i(B MADV_FREE?
> # $B$"$l!"$G$b%a%b%j$,$J$/$F(B valid $B$K$7$H$/$N$bJQ$JOC$@$J$!(B..

sbrk $B$K$h$C$F;HMQ2DG=$K$J$C$?%a%b%j6u4V(B(BSS)$B$,$"$C$?$H$7$F!"(B

|----+----+----+----+----+----+----+----+----+----+----|

 <---------- in use ---------> **** <----- in use ---->

**** $B$N%Z!<%8$@$1$,$$$^;H$o$J$$>l9g$K!"(B
MADV_FREE $B$H$9$k$3$H$G$3$NJ,$N;q8;$r$h$j8zN(E*$KMxMQ$G$-$k$h$&$K$J$j$^$9!#(B

$B$G!"$J$*$+$D(B **** $B$NItJ,$K%"%/%;%9$9$k$3$H$O(B SEGV $B$N860x$K$J$j$^$;$s!#(B
$B$3$l$,(B keeping the address space valid $B$H$$$&$3$H$@$H;W$$$^$9!#(B

$B!V$3$N%a%b%j$O:#$O;H$o$J$$$+$iJV5Q$O$7$J$$$1$I>!<j$KCf?H=q$-49$($F$b$$$$$h!W(B
$B$H$$$&DLCN$G$9!#(B


> $B$"$HC1$J$k6=L#$J$s$G$9$,!"2>$K6u4V$,;D$k$H$7$F!"$=$3$K$K2~$a$F%a%b%j$r(B
> $BE=$jIU$1$k$N$O$I$&$d$C$F$k$s$G$7$g$&(B?

References made to that address space range will not make
the VM system page the information back in from backing store
until the page is modified again.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
$B$H$"$k$h$&$K!"<!2s=q$-9~$_$r$9$l$P(B MADV_FREE $B>uBV$,2r$1$F(B
$BDL>o$N%a%b%j6u4V$H$J$s$iJQ$o$i$J$/$J$j$^$9!#(B

-- 
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|  $B>>:j(B $BAGF;(B (Motomichi Matsuzaki/maki)    mailto:mzaki@e-mail.ne.jp  |
|          $BEl5~Bg3XBg3X1!(B $BM}3X7O8&5f2J(B $B@8J*2J3X@l96(B $BH/@8@8J*3X8&5f<<(B  |
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