Read TCN-register in user space

[Kumar Gala]

There is a proper way to do this and hackish way.  The proper way is to 
eventually provide some interface via the work BenH has been doing with 
vDSO (while out).  The hackish way is to export it via some /proc or 
sysfs attribute.  The hackish way will not make its way into a mainline 
tree.

- kumar

On Mar 7, 2005, at 5:02 AM, Björn Östby wrote:

> I'm currently using ELDK 3.0 (kernel 2.4.25) and a mpc823e trying to 
> do some latency measurements for my final thesis project.
>
> I'm wondering if there is any possibility to read the Timer Counter 
> Register (TCN1) in user space. I have initially used gettimeofday(), 
> which provides sufficient resolution (usec), but I suppose that 
> solution probably adds on some kind of unknown context-switch latency. 
> Does anyone have a clue on how to access this in user space? Could 
> inline assembler or perhaps mmap() do the trick (I'm using C as 
> programming language)?.
>
>
>
> Regards,
>  Bjorn
>
>
>
>  <ATT07173.txt>