Performance regression, 2.2.3/recent?

[Phil Pennock]

On 2017-12-03 at 12:19 +0100, Werner Koch wrote:
> On Sun,  3 Dec 2017 02:20, gnupg-users at spodhuis.org said:
> > Anyone else seeing major slowdowns with keyring dumping in recent GnuPG
> > on Linux?
> 
> By recent do you mean 2.2.3 or a Git version (2.2 branch or master)?

2.2.3.

The dump on Linux finally finished; zsh reports:

  1591.65s user 2111.87s system 99% cpu 1:01:45.97 total

Just over an hour, for something which was already slow at 27 seconds on
macOS.  System was never short on RAM.  It is a smallish Atom computer,
2GiB RAM, two-core Atom(TM) CPU D2500.

If I reinstall an older version:

  apt install optgnupg-gnupg=2.1.23-pdp1
  time gpg --with-colons --with-fingerprint --with-subkey-fingerprint --with-secret --list-keys >foo3
  301.22s user 257.94s system 99% cpu 9:22.54 total

GnuPG 2.1.23:  9mins 22s
GnuPG 2.2.3 : 61mins 45s

At this point, I really have no idea what is a good path to investigate
where this time is being spent.  It's a 236M .kbx which I'm willing to
share.