[MERGE] iter-changes based commit

[Ian Clatworthy]

Robert Collins wrote:
> On Tue, 2007-09-04 at 09:33 +1000, Ian Clatworthy wrote:
>> Ian Clatworthy wrote:
>>> The attached patch speeds up a commit of 6 new files by 15% on a Mozilla
>>> tree: 30.4 secs to 25.9 secs.
>> It also speeds up initial commit by 20%: 4m -> 3m12s.
> 
> I'd like this to hold off 3-4 days please. I have detangled most of the
> cause of triple-stats and multiple path calculations in commit I think,
> working inside-out - and I hope this will have comparable wins - it
> certainly should solve more impedance mismatch than this patch does
> AFAICT.

That's great news. Sounds like commit will get quite a boost in 0.92.

Ian C.