more craziness - pre-cache in init scripts.

Carsten Haitzler (The Rasterman) raster at openmoko.org
Fri May 16 11:44:42 CEST 2008


On Fri, 16 May 2008 11:40:58 +0200 "Alessandro Iurlano"
<alessandro.iurlano at gmail.com> babbled:

> > yes - just loads. yes i know shared libs are loaded once only - and only the
> > pages from them loaded as needed. sure if you want to do full
> > block-analysis on what pages are mapped in and just read those - wonderful.
> > i'm going for a quick and dirty solution. this does not SPEED up boot - not
> > at ALL. it moves IO time from later to earlier. it means that once the
> > bootsplash goes away, X, WM< application launcher and all that stuff come
> > up much faster so the visible gap between bootsplash and "i have a gui up i
> > can now use" is much less. it avoids filesystem IO to flash later while
> > these are starting up :) so it's just shuffling stuff. yes - even reading
> > more data off disk than we need and it may slow down the total boot time -
> > but it will improves its look and feel. so this is just to get the whole
> > bootup looking slicker and polished and professional.
> 
> I understand what you are trying to do and why. I just wanted to point
> out that maybe the gain could be very little if the flash memory speed
> is high and that it could be bigger by launching a program that uses
> those libs.
> Maybe adding LD_BIND_NOW=1 to that program to force the linker resolve
> all the symbol could be worth trying.
> 
> Anyone has raw numbers about the speed of internal flash memory?

well i KNOW that when you bring up these apps after being run once they come
up much faster. that is a god indicator of needing to wait on IO :)

-- 
Carsten Haitzler (The Rasterman) <raster at openmoko.org>



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