Re: [RFC PATCH] index-pack: improve performance on NFS
- From
Junio C Hamano <gitster@pobox.com>
- Date
- Oct 29, 2018, 00:48 UTC
- Message-ID
- <xmqqbm7da88t.fsf@gitster-ct.c.googlers.com>
- In-Reply-To
- <20181027093300.GA23974@sigill.intra.peff.net>
Jeff King <peff@peff.net> writes:
Show 7 quoted lines
> Of course any cache raises questions of cache invalidation, but I think > we've already dealt with that for this case. When we use > OBJECT_INFO_QUICK, that is a sign that we want to make this kind of > accuracy/speed tradeoff (which does a similar caching thing with > packfiles). > > So putting that all together, could we have something like:
I think this conceptually is a vast improvement relative to ".cloning" optimization. Obviously this does not have the huge downside of the other approach that turns the collision detection completely off.
A real question is how much performance gain, relative to ".cloning" thing, this approach gives us. If it gives us 80% or more of the gain compared to doing no checking, I'd say we have a clear winner.
Show 5 quoted lines
> That's mostly untested, but it might be enough to run some timing tests > with. I think if we want to pursue this, we'd want to address the bits I > mentioned in the comments, and look at unifying this with the loose > cache from cc817ca3ef (which if I had remembered we added, probably > would have saved some time writing the above ;) ).
Yup.