Re: Huge performance bottleneck reading packs

> On Wed, Oct 12, 2016 at 07:18:07PM -0400, Jeff King wrote:
>
>> Also, is it possible to make the repository in question available? I
>> might be able to reproduce based on your description, but it would save
>> time if I could directly run gdb on your example.

> I tried this by making a bunch of packs in linux.git (my standard "this
> is pretty big" repo), like so:
>
>   for i in $(seq 1000); do
>     git rev-list --objects HEAD~$((i+1))..HEAD~$i |
>     git pack-objects --delta-base-offset .git/objects/pack/pack
>   done
>
> and then doing a 25,000-object fetch from upstream (no significance to
> the number; that's just how far behind upstream I happened to be).
>
> However, I didn't notice any regression. In fact, it was much _slower_
> than v1.9.0, because that older version didn't have threaded index-pack.
>
> If you can't share the repo directly, can you tell us more about your
> fetch? How many objects are in your repository? How many objects are
> fetched? How many refs are there on the remote side?