Re: -mm seems significanty slower than mainline on kernbench
From: Martin J. Bligh
Date: Mon Jan 23 2006 - 23:40:29 EST
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.
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/