Very strange measurements

[Brecht Vermeulen]

Eddie Kohler wrote:
> 
> These are weird worrisome numbers!
> 
> > * however, I took click 1.0.6 (tested also click 1.1 and later, but
> > these gave the same results)
> 
> There's a grammar ambiguity here. Was Click-1.0.6 the last release that
> behaved well? Or is current CVS the first release that behaved badly? Which
> other releases did you try?
> 
> I'm assuming that you meant Click-1.0.6 was the last release that behaved
> well:

the assumption is correct. click-1.0.6 was the last one behaving well
(haven't tried 1.1b though, I tried 1.1, and the cvs versions of
30-05-01 and 7-04-01).

> 
> > Does anyone has an explanation for this behaviour (and what was the big
> > chance between click 1.0.6 and later versions ?) or do we have to burn
> > our GHz processors :-) ?
> 
> ---
> 
> > it sounds very much like a scheduling thing.
> > long latency due to some weird scheduling issue.
> 
> Benjie -- What scheduling issue in our code would differ between a
> K6-500MHz and a K6-1GHz?

The 1 GHz is an athlon. Benjie has asked me to try something in
routerthread.cc. I'll try this today, but can't switch network cards
remotely for now.

> 
> Brecht, the polling interface was significantly changed between 1.0.6 and
> 1.1b1. Benjie rewrote a lot of stuff.
> 
> My first guess: Are there any weird prefetching instructions remaining in
> current Click when ENABLE_INTEL_CPU is not defined? Maybe K6-1GHz reacts
> badly to these.
> 
> Brecht, more information, if you can? Can you run the PollDevice with its
> profiling on (CLICK_DEVICE_STATS #defined), and tell us the results
> (returned by "calls" handler)? Is PollDevice slower, or the device driver?
> 

I'll do my best :-).


thanks for the response.

brecht