[Dev] 0.7 perf goals

[Philippe Bossut]

Katie Capps Parlante wrote:

> This approach seems pretty reasonable for Mozilla (or Safari, which I 
> hear has a similar system), where the intense focus is on a particular 
> well-known use case. In our case, we're continuing to tweak the 
> functionality and even change the formulation of the use cases that we 
> measure. I think it would be overly constraining at this point to have 
> a formal "back all regressions out" policy. 

Agree. The "back out regressions" policy was also used on MacIE (and MSN 
for OS X). It was extremelly efficient but, as Katie said, was focusing 
on well-known use case and a particularly stable feature set. I think 
that enforcing this policy on Chandler (or Cosmo for that matter) right 
now would lead to Premature Optimization issues for any significant 
feature we add.

Note that we (MacIE) also used a historized graph (as recommended by 
Alec and others) and it's only when we got that implemented that people 
(devs) could make sense of the data and we started to see significant 
perf improvments.

Cheers,
- Philippe