[darcs-devel] announcing darcs 2.0.0pre1, the first prerelease for darcs 2

David Roundy droundy at darcs.net
Sat Dec 15 19:15:02 UTC 2007

On Sat, Dec 15, 2007 at 05:38:43PM +0100, Petr Rockai wrote:
> > Anyhow, it'll be a couple of hours before tests are passed and changes are
> > pushed, but then I'd appreciate it if you'd take another look at this! (I
> > could do it myself but right now I think I need a break... and it's far
> > easier to motivate myself to fix a problem pointed out by someone else than
> > to look for said problem myself.)
> Okey, I have pulled in your changes and re-ran the test:
> 35: 6.8s
> 36: 7.6s
> 37: 8.5s
> 38: 9.4s
> 39: 10.3s
> 40: 11.4s
> 41: 12.6s
> 42: 14.2s
> ...
> 55: 44s
> 56: 55s
> 57: 53s
> (Okey, towards the end, this probably got a little skewed by other
> stuff running on the box.)

Thanks for running this test!  :)

> I will have to think a little to see what kind of function this is,
> asymptotically. It grows faster than both n^2 and n^3 and apparently
> slower than 2^n. I may have made a mistake somewhere.

Yay, this is more like it!

You might get better fitting if you subtract 1s from the times, or use CPU
times rather than elapsed time, because darcs pull sleeps for a second.
But maybe you've already done this.

There may be yet more low-hanging fruit, although obviously nothing as
low-hanging as what I've just picked.

> So with the changes, it is again a *lot* better, with the 10s depth
> going from 15 to 38 or so. Thanks for the improvement!

You're welcome! It was definitely a relief to discover that I hadn't
inadvertently ended up with an algorithm that was exponential in time (for
any of the important stuff, anyhow)!

> (I have been thinking about the "ultimate" solution since I got up
> today; if I ever reach a state where I no more see "why it won't
> work", I will mail the list...)

Sounds good.  More brains better.
David Roundy
Department of Physics
Oregon State University

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