Making diff fast (was Re: Some notes on distributed SCM)

[Daniel Phillips]

On Sunday 10 April 2005 18:17, Aaron Bentley wrote:
> Benno wrote:
> > 1/ Caching the working tree stat data, and then being able
> > to simply stat each file and compare the stat information.
> >
> > Pros: Portable, simple to use.
> > Cons: Still requies a full search of the tree which is slow.
>
> This is what Arch does, and it's quite slow on large trees.  Robert
> Collins has recently improved this in Baz, but it doesn't change the
> fact that it's an O(versioned files) operation, rather than O(changed
> files).

But statting the full working copy kernel tree takes less than .1 second if 
the dentries are in cache, and it takes less than 5 seconds to get them in 
cache.  What is wrong with that?

Regards,

Daniel