tunning kernel memory cache

hello
sorry for english in the french ML but this mail is sent into english ML too
I'm creating a script to tune the system VM according to SA wishes for
sorcerer

I begun to write this because I have two boxes a laptop (target MAX
power saving) and a desktop (target max perf)

the desktop has 1G ram so my aim is to use the maximum ram to boost perfs
a cat /proc/meminfo shows me that only 64M is dedicated to cached datas
..... I seeked then to increase this value.....

looking the web only gived me information about 2.4* kernels..... but
nothing for 2.6!

I found /usr/src/linux/Documentation/filesystems/proc.txt that gived me
some usefull information to "pack transferts" for laptop
like

echo 120000 > /proc/sys/vm/dirty_writeback_centisecs
echo 120000 > /proc/sys/vm/dirty_expire_centisecs
echo 90 > /proc/sys/vm/dirty_background_ratio
echo 1 > laptop_mode

I then looked the web for remaining entries in proc that wasn't
explained there
echo 20 > /proc/sys/vm/swappiness

.... but nothing to increase for exemple minimum number of blocs to read
per acces (min readahead) and such things

what fun is that now I'm able to have "big grouped writes" but no "big
grouped reads" that should be used for laptops.....
does anyone has information on how to tune a 2.6 kernel WM?

thanks