[darcs-users] darcs patch: add exception to haskell_policy.sh for D... (and 61 more)

Jason Dagit dagit at codersbase.com
Thu Oct 30 20:09:36 UTC 2008

On Thu, Oct 30, 2008 at 1:00 PM, David Roundy <droundy at darcs.net> wrote:
> On Wed, Oct 29, 2008 at 07:50:32PM +0000, Eric Kow wrote:
>> On Wed, Oct 29, 2008 at 10:30:12 -0700, Jason Dagit wrote:
>> > I want to see benchmarks too, but I thought I would justify why we
>> > expect this to be no slower than the previous code...Everything below
>> > is stuff that we discussed during the Sprint.
>> Well, attached is a second set of comparative timing tests, sorry, only
>> run once and with no nice output yet.  Hopefully you can use a graphical
>> diff tool to do side by side comparison.
>> A nice little summariser script, maybe using the Haskell tabular
>> library might be handy
> I've run my own set of timings, which give considerably more dramatic
> differences than yours show, perhaps because I ran my tests on large
> repositories?
> I'll summarize my results up here, but you can look below for a more
> verbose summary.  The new code is almost always faster by my reckoning, and
> often *much* faster (as much as a factor of three!).

Very nice.  Just curious, how many trial runs did you do?

> I do, however, observe a performance regression on darcs annotate Setup.hs
> (run in the darcs repository).  It's a small regression (smaller than
> Eric's tests show), but reproducible.  And it's all the more striking given
> the dramatic improvement the new code shows in all the other tests, which
> suggest there may be a single function that has a large performance
> regression (since it seems likely that parts of the annotate command have
> been sped up in the new version).  I don't have the time or inclination to
> track down this issue, but I do hope Don is interested enough to look into
> it!

If we're going to accept this, it may be better to look at the
annotate issue after Ganesh's patches go in.  Otherwise there is
potential to waste effort optimizing something that is going to be
removed or rewritten, right?


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