open question on flash speed/app blocking

[Cam Mayor <cmayor@iders.ca>]

Hi all,

We're making an app that periodically writes a persistance file to flash.  I 
haven't actually gotten a flash file system area working yet on my board, so 
i can't test this yet for speed.   I know that the results will vary with the 
hardware, the filesystem used, and a handful of other factors.  I'm assuming 
that a write to the flash will be blocking - that is, nothing else will be 
allowed to happen on the bus while that function is being performed.

For a file the size of 32bytes, 1kByte, and 32kBtyes, what kind of blocking 
delay might one expect from linux writing to flash for each of those file 
sizes?  What would be an optimum flash filesystem to use for something like 
this?  (if there is one)

cheers,
cam

ps. i'm using linux 2.4.6-rmk1-rayl1 and 2.4.16-rmk2.  I could use the latest 
kernel, too, i just haven't gotten around to it.  For development purposes, 
i'm using a cirrus CDB89712 development board, which has the cs89712 
processor and some Intel 28f320B3 flash on it.