[Lazarus] Some syntax changes

Bernd Kreuss prof7bit at googlemail.com
Sun Aug 1 13:26:05 CEST 2010


On 01.08.2010 11:47, Mattias Gaertner wrote:

> the OS file cache

The OS cache already does a great Job:

root at t40:/home/bernd\ $ sync && echo 3 > /proc/sys/vm/drop_caches

bernd at t40:~/lazsvn/lazarus/trunk\ $ time make ide
[...]
real    1m12.491s
user    0m8.653s
sys     0m2.348s

bernd at t40:~/lazsvn/lazarus/trunk\ $ time make ide
[...]
real    0m6.127s
user    0m4.752s
sys     0m0.916s

1:12 with a cold cache versus 0:06 when the cache is warm is an 
impressive difference.

There exists a small tool for linux that tries to speed up file access 
with an extremely pragmatic but very effective approach by simply 
permanently monitoring which files are usually read most often by all 
the user's applications and then as a daemon running on idle priority 
permanently read all those files in intervals of a few minutes which 
will ensure that they are always all in the OS file cache.

Lazarus could adopt this idea and could after opening a project during 
idle time and in reasonable intervals read every file that would also be 
read by the compiler and linker. Maybe in a certain order that makes 
sense: first only the directory listings to immediately have all file 
timestamps, then all compiled units that would be needed (because most 
source will not have changed since it was compiled the last time) and 
then after this is done read all source files belonging to the project.




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