Re: What's cooking in git.git (topics)

From: Linus Torvalds <torvalds@linux-foundation.org>
Date: Apr 29, 2007, 18:45 UTC
Message-ID: <alpine.LFD.0.98.0704291142510.9964@woody.linux-foundation.org>
In-Reply-To: <7v3b2jdo9h.fsf@assigned-by-dhcp.cox.net>

On Sun, 29 Apr 2007, Junio C Hamano wrote:

>
> * lt/objalloc (Mon Apr 16 22:13:09 2007 -0700) 1 commit
>  - Make the object lookup hash use a "object index" instead of a
>    pointer

I think you should just drop this.

You merged the two patches that made this possible, and the third in the series isn't really worth it. I can re-create it at will (maybe better) now that the core object allocations are all cleaned up, and that patch simply didn't give enough of an advantage to be worth it.

Maybe inlining the object index -> ptr conversion would have solved the performance regression, but it migth also be something more fundamental, like the potential extra cache miss in the converstion part (when looking up the allocation block).

So it was interesting to try, but I don't think it's worth carrying around considering the results.

		Linus