Re: three-way diff performance problem

[Linus Torvalds <torvalds@linux-foundation.org>]

On Tue, 21 Jul 2009, Linus Torvalds wrote:
> 
> Now, being a git person, what does that say? Right: just check in the 
> working kernels as two branches under the same filename, then merge the 
> branches, and force the merge result to be the non-working kernel, and do 
> a three-way combined context diff! So I did exactly that.

Btw, I did it wrong, which is why it takes too long. Instead of making the 
result be the right dump-file, I made it be a bad one, so the diffs are 
much bigger than they should be. Which then makes the combined-merge diff 
take longer than necessary (with the O(n^2) thing).

Doing it _correctly_ actually made the three-way diff only take 45 
seconds, but sadly still left me with 22 thousand lines.

			Linus