Re: [PATCH] pack-objects: fix performance issues on packing large deltas

>
> On Fri, Jul 20, 2018 at 9:47 PM, Duy Nguyen <pclouds@gmail.com> wrote:
> > On Fri, Jul 20, 2018 at 10:43:25AM -0700, Elijah Newren wrote:
> >> Out of curiosity, would it be possible to use the delta_size_ field
> >> for deltas that are small enough, and only use an external data
> >> structure (perhaps a hash rather than an array) for the few deltas
> >> that are large?
> >
> > We could. And because repack time is still a bit higher in your
> > linux.git case. Let's try this. No locking in common case and very
> > small locked region when we hit large deltas
>
> This one looks like a winner.  Labelling this as fix-v7, this rounds
> out the table to:
>
> Version  Time (s)
> -------  --------
>  2.17.0   621.36
>  2.18.0   621.80
>  fix-v5   836.29
>  fix-v6   831.73
>  fix-v2   619.96
>  fix-v7   622.88
>
> So the runtime is basically within the noise of different runs of the
> timing for 2.17.0 or 2.18.0 or -v2, and is much faster than -v5 or
> -v6.