Re: [PATCH/RFC 3/3] ath5k: trace resets

[Bruno Randolf <br1@einfach.org>]

On Wed July 21 2010 12:41:50 Bob Copeland wrote:
> On Wed, Jul 21, 2010 at 10:04:59AM +0900, Bruno Randolf wrote:
> > the difference. without tracing you can get 22Mbps, with tracing max
> > 15Mbps UDP thruput.
> 
> If so, and it's not an i-cache effect, then something is wrong with
> the tracing subsystem.  It's supposed to compile to something like
> 
> if (tracing) {
>    trace_callback();
> }
> 
> That is exactly what we have with the debug infrastructure, but
> the debug stuff is theoretically a bit worse since it tests for
> tracing inside the callback.

but that's for all tracepoints all over the kernel... i think it's natural 
that this takes some CPU time. note that on these boards even the 22Mbps are 
limited by the CPU processing power.

> Oh well, I guess I need to get my hands on one of these boards.

could be helpful, allthough i have to admit that these boards are getting old 
and more current embedded boards usually do have faster CPUs...

bruno