Re: Kernel / Userspace Data Transfer

[Ross Dickson <ross@datscreative.com.au>]

lml@beonline.com.au wrote: 
 > I have a set of counters in a Kernel module that i want to export to a 
 > userspace application. I originally decided to use a /proc entry and parse 
 > the output whenever the userspace application needed this data, however, 
 > i need more than the 4096 that is allowed in /proc and i'm not too keen 
 > on parsing large chunks of text anyway. 
 > 
 > What i would like to do is copy these slabs of text from the kernel to my 
 > userspace application (whenever the application requests it). I've seen the 
 > 'copy_to_user' function and it looks usefull, but have no idea where to start 
 > or how to use it :-/ 
 > 
 > Can someone provide and example or point me in the right direction? Or is there 
 > a better place to ask this question? 
 
Here is a good starter on-line reference
http://www.faqs.org/docs/kernel/
Relevant page
http://www.faqs.org/docs/kernel/x848.html
or as pdf
http://www.tldp.org/LDP/lkmpg/lkmpg.pdf

There is also mbuff that maps shared memory between kernel and user space.
It is pretty easy to use.
http://sourceforge.net/projects/mbuff/

Regards
Ross.