Enclosed are two little test programs. They both do the following:
* open 24 files (all the same size, about 23MB)
* getting 256kB of data from each file into unpageable RAM
* move along 256kB
* release previous 256kB of unpageable data
* repeat until we reach the end of the files
One program uses mmap/mlock to accomplish the lockdown, and calls
munmap to release the previously locked chunk.
The other locks down a malloc-ed buffer for each file, and uses read
to move the data into user space.
I was very disheartened to find that on my system the mmap/mlock
approach took *3 TIMES* as long as the read solution. It seemed to me
that mmap/mlock should be at least as fast as read. Comments are
invited.
--p
begin 664 mmrtest.gz.uu
M'XL(``=QZC@``^U7ZT_<1A#GZ_FOF!)=>C[,G>\%4DFB7._<%H4$=(>$*$66
M\8.SL->6O2Y*4_[WSJ[7QO9=@:2A5=3]??!C=M;S7L^$(753VK.WGA$#7=_;
M&\,6P&!_HHO[@-TY)OIH`K"O[P_'>Z/!WA"7]='>9`OTYU2J0)92*P'8BJ^<
M!_D>6_]&\<(G=I`Y+KQ*J>-'O=4;I4I*?')=I[E)0M;8G,"_JM,RXB.Y3O-L
M0H/&UH]I/PPMLD[%L-`ZU4K#?FQ=N^O4,$T847GAN)Y/7)B=SXZ,I7EB+,SW
M2V.&.3:>Z(B>[I4\1\>S=_/CLP_FC^>GQI+EX<GT9\-<'OYJ0!=&PY+QP^EB
M.GNWA'L,QY67DF]^N#!FI\>+\W)INT^MV.T/QSTK<:(LV584^C%VD1_0LYE-
MX9/"^'Q"P7,.^'/J_^&:^.H'KLF><ZJ]8CG:14_%YE7F>6Y2XPZ#R+XQ62+3
M#727X+?O@"86OB"#@O*4_"UU:19#1RQ!EVJYJ&YLT96J*)^4EM"4A8-?4#Q^
MHN5[T.G0W3>>`Z\ABET"';9'@V-S,3];J"J\`EU%`ULM+\8LHLB/"8'9H\&V
M;9'O:;Z+&0KM]#>RK0$7>H`[$E0K(;`[P)<[%.9QZ;DX#5X*-1@K(Q6N0D7$
M2B^EPGF<H^(VY.GD%JK`R-#1-:A^1`.4CSA9')^:"V,Z_Y,_G2T.3PT-WD]/
MS.4OTX4QUW(VH9*N%CYIBJO(8YM_FAX>&?/<+X5;F#M(A-%BZK13E?L"W8Z^
MBA+H\()3-_J%";L//=JF'U2(&'<D-?*\"\.#7%/.U%28.Z/<KOY=`-O.#R"T
M=B+,7Y_Z5@#BB\($YB`0_GF"-8P;31)$-.2NEJ@KWZ/51,V3,R.I?TU<!X*(
M7`-=N40#$MT6P0@SPIW:",H.U!W'8\[*INZKIU@O!'RAR4J_WTH<FMH!ZHC*
MJP^%IJHVQJ90^O-U_D=AJFB,CD8&))2)S(2T,^CUV)5&T0VT>R,/PM2U>84S
M9E$RQ>.]/6N4G;IINX.<I>,%D455+A]V>=!5Z#?/?*;Z6H'L-,NA62X;&,JR
M9B?=:Y@T:I>9S':^929''EX+IPJ?BL>*G6*M.'%44<QKF1]:/IZJ[.=@)==V
M<3+C\^\7EX^D?ZLH%'Y/+\0_[)+E%W[/%_<(62+3C@CU2<9/2X\%W^<G"?AX
MA(N-^+*SDUO.M6`G-6;EQ6AXR7:UTL(?8H$E7-IO.ST=C[+RQZCA5P;\I,Q]
M6OT%O12:^I=:\761RYO_'RR1<2O@7KX3V@X_-WV>LX4S6<ZR0F/^K1N+)@Z8
M)K<K]@/JU!=SP<W*?()SJG;E)]:]784YZXKH7.765>):-_SQ+M>Z46F5K.LR
M@!4$(L`;BZWU.;6REH$,_W5S*O'L"/G\-WS6`?"1^6\TQA<Q_XV'HQ&;_\;C
M?3G__1N0\]^W,/\):AREV&E'I#(4=OD\]C^=[A@#$FI#'?X4(QLZC;:XG`C*
MSIIW*4]LGD6_P?<ZT2T!T9&WG2]MH[GJ13CS%N`KSSXQ=A-.Z=7-!G-ZH84*
MW[U6-HU!#TP47(9G88R>[HFF\9N:<MD+RUY8]L(2$A(2$A(2$A(2$A(2$A(2
,7P-_`3F.1\@`*```
`
end
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.rutgers.edu
Please read the FAQ at http://www.tux.org/lkml/
This archive was generated by hypermail 2b29 : Fri Apr 07 2000 - 21:00:13 EST