Re: heads-up: git-index-pack in "next" is broken

[Davide Libenzi <davidel@xmailserver.org>]

On Tue, 17 Oct 2006, Linus Torvalds wrote:

> > Does this mean that, with your own change to xdiff that has just been 
> > committed, you actually created a "problem"?  Because this is a change 
> > that creates different behaviors whether a 32-bit or 64-bit architecture 
> > is used, Right?
> 
> If you go back to that discussion, I actually pointed out several times 
> that the whole bug _was_ actually introduced exactly because the xdiff 
> code used things that behave differently depending on word-size.

Ehm, I think there's a little bit of confusion. The incorrect golden ratio 
prime selection for 64 bits machines was coalescing hash indexes into a 
very limited number of buckets, hence creating very bad performance on diff 
operations. The result of the diff would have been exacly the same, just 
coming out after the time for a cup of coffee and a croissant ;)


> So the bug in xdiff was _exactly_ that somebody - totally incorrectly - 
> thought it should work "better" on 64-bits. 

Haha, not exactly. I had just forgot about the incoming 64 bits world at 
the time.



- Davide