[PATCH] who: remove OpenJDK

[Joerg Sonnenberger]

On Sat, Jul 25, 2020 at 01:36:32PM -0400, Josef 'Jeff' Sipek wrote:
> First off, the clone itself.  I cloned it from the official upstream repos.
> My internet connection is 150 Mbit/s, the storage is a 3-way ZFS mirror.  I
> used hg 4.9.1 (py27), and git 2.21.0.  (I know, I need to update both.  This
> is on a box that has a solid network connection but is harder to update.  If
> there is interest I can spend the effort to update them and re-run it with
> newer versions.)

It should be noted that for all intends and purposes, a git clone is
much more comparable to hg clone --stream.

> Now, hg specifics.  It looks like the manifest is huge.  This corresponds to
> how long it took to download.
> 
> -rw-r--r--   1 jeffpc   jeffpc     25.2M Jul 25 12:16 00changelog.d
> -rw-r--r--   1 jeffpc   jeffpc     3.68M Jul 25 12:01 00changelog.i
> -rw-r--r--   1 jeffpc   jeffpc      434M Jul 25 12:09 00manifest.d
> -rw-r--r--   1 jeffpc   jeffpc     3.67M Jul 25 12:09 00manifest.i

I have similar reservations about the way manifests are handled for the
NetBSD repository. It's been a topic of discussion recently on IRC. The
manifest processing itself currently takes nearly half of the total
clone time and that looks ...suspicious at best.


> I'm guessing that they would have benefited from treemanifest.

>From my testing, treemanifests don't help at all.

> I also tried to clone locally to see what sort of thing a user would see.
> 
> $ hg clone jdk-hg test
> $ git clone jdk-git test-git
> 
> hg took 60 seconds (with hot cache, ~120 secs cold cache), git took 13
> seconds.  Git hardlinked the one big pack file, while hg hardlinked each of
> the file in .hg/store.  Obviosly, hardlinking 2 files is much faster than
> hardlinking ~180k.  (treemanifest would have made this even worse for hg.)

Using a unified storage would help somewhat in general, but I don't
consider local clone a big use case. share serves the purpose generally
much better.

> I just kicked off a conversion to treemanifest.  It'll take a while.

Did you convert to generaldelta and etc already?

Joerg