Re: [RFC PATCH] index-pack: improve performance on NFS
- From
Jeff King <peff@peff.net>
- Date
- Nov 12, 2018, 14:31 UTC
- Message-ID
- <20181112143128.GA9913@sigill.intra.peff.net>
- In-Reply-To
- <87lg635hz4.fsf@evledraar.gmail.com>
On Thu, Nov 08, 2018 at 11:20:47PM +0100, Ævar Arnfjörð Bjarmason wrote:
Show 17 quoted lines
> Just a comment on this from the series: > > Note that it is possible for this to actually be _slower_. We'll do a > full readdir() to fill the cache, so if you have a very large number of > loose objects and a very small number of lookups, that readdir() may end > up more expensive. > > In practice, though, having a large number of loose objects is already a > performance problem, which should be fixed by repacking or pruning via > git-gc. So on balance, this should be a good tradeoff. > > Our biggest repo has a very large number of loose objects at any given > time, but the vast majority of these are because gc *is* happening very > frequently and the default expiry policy of 2wks is in effect. > > Having a large number of loose objects is not per-se a performance > problem.
Yes, you're right. I was trying not to get into the rabbit hole of discussing theoretical tradeoffs, but it is worth addressing. I've updated that commit message in the patches I'll send out momentarily.
-Peff