[Cbe-oss-dev] [PATCH] spufs: marker-based tracing facility

[Julio M. Merino Vidal]

On 27/11/2007, at 19:55, Christoph Hellwig wrote:

> This adds markers two important points in the spufs code and a new
> module (sputrace.ko) that allows reading these out through a proc  
> file.
>
> Long-term I'd rather see something like lttng extended to use the  
> spufs
> instrumentation, but for now I think this is a good enough quick
> solution.  We'll probably want to add various addition event in  
> addition
> to that ones I have already.

I'm currently doing this exact same thing.  My first approach also  
consisted on creating a proc file and then read the events from it,  
but I later found SystemTap, which seems to be a more versatile  
solution to these situations.  Aside from markers, it lets you hook  
to the function level based purely on debugging symbols.

What I have now is just a set of markers in the spufs code and a  
tapset for SystemTap to capture them from userland, without the need  
to use any extra proc file nor module.  (Which is trivial, and I  
think we can easily get this tapset integrated into SystemTap's  
distribution.)

Does your approach have any advantage over using, e.g. SystemTap?  If  
not, I'd advocate using this tool instead, given that you also  
mention that using lttng in the long term should be preferred (but I  
don't know how hard it would be to extend it to use these markers).

Kind regards,

-- 
Julio M. Merino Vidal <jmerino at ac.upc.edu>