Re: -mm seems significanty slower than mainline on kernbench

["Martin J. Bligh" <mbligh@google.com>]

> Oops.  I was looking at the graphs for Moe but 
> <http://test.kernel.org/perf/dbench.elm3b132.png> doesn't appear to be 
> demonstrating a problem either.  Given the fluctuation in the 
> 2.6.16-rc1 results (235, 234, 211, 228.5 and 237.5), the results for 
> 2.6.16-rc1-mm1 (229) and 2.6.16-mm2 (219) aren't significantly different.

I disagree. Look at the graph. mm results are consistent and stable, and 
significantly worse than mainline.

> Peter
> PS I have a modification for kernbench that calculates and displays 
> the standard deviations for the various averages if you're 
> interested.  This would enable you to display 95% (say) confidence 
> bars on the graphed results which in turn makes it easier to spot 
> significant differences.

Thanks, but I have that. What do you think those vertical bars on the 
graph are for? ;-) They're deviation of 5 runs. I throw away the best 
and worst first. If it was just random noise, then you'd get the same 
variance *between* runs inside the -mm train and inside mainline. You 
don't see that ...

Use the visuals in the graph .. it's very telling. -mm is *broken*.
It may well not be the same issue as last time though, I shouldn't
have jumped to that conclusion.

M.