Re: pack operation is thrashing my server

On Fri, 15 Aug 2008, Björn Steinbrink wrote:

Since you mention the delta cache, uau (no idea about his real name) on
#git was talking about some delta cache optimizations lately, although
he was dealing with "git log -S", maybe it affects rev-list in a similar
way. Unfortunately, I can't seem to find any code for that, just a
description of what he did and some numbers on the results in the IRC
logs.

Yes, interesting.

The delta cache was really a huge hack that just turned out rather 
successful. It's been hacked on further since (to do some half-way 
reasonable replacement with _another_ hack by adding an LRU on top of it), 
but it really is very hacky indeed.

The "hash" we use for looking things up is also pretty much a joke, and it 
has no overflow capability, it just replaces the old entry with a new one.

I wonder how hard it would be to replace the whole table thing with our 
generic hash.c hash thing. I'll take a look.

			Linus