Re: Something is broken in repack
- From
Junio C Hamano <gitster@pobox.com>
- Date
- Dec 8, 2007, 22:18 UTC
- Message-ID
- <7vodd0vnhv.fsf@gitster.siamese.dyndns.org>
- In-Reply-To
- <alpine.LFD.0.99999.0712072032410.555@xanadu.home>
Nicolas Pitre <nico@cam.org> writes:
Show 14 quoted lines
> On Fri, 7 Dec 2007, Jon Smirl wrote: > >> Starting with a 2GB pack of the same data my process size only grew to >> 3GB with 2GB of mmaps. > > Which is quite reasonable, even if the same issue might still be there. > > So the problem seems to be related to the pack access code and not the > repack code. And it must have something to do with the number of deltas > being replayed. And because the repack is attempting delta compression > roughly from newest to oldest, and because old objects are typically in > a deeper delta chain, then this might explain the logarithmic slowdown. > > So something must be wrong with the delta cache in sha1_file.c somehow.
I was reaching the same conclusion but haven't managed to spot anything blatantly wrong in that area. Will need to dig more.