[Samba] is sssd *faster* than samba4's builtin winbind?

[Trent W. Buck]

Using samba 4.0.9 as an AD DC (no other domain servers).
Since my UIDs and GIDs have changed, I was doing cleanup:

    find /srv/svn/ -xdev '(' -nouser -o -nogroup ')' -ls

I noticed this was very slow -- iostat reported only about 2tps and
50kB/s to my disks.  So I timed it with nsswitch.conf users & groups set
to "files" vs. "files winbind":

    # with "files"
    root at gumbo:~# time find /srv/svn/ -xdev \
                  '(' -nouser -o -nogroup ')' -printf x >x
    real    0m1.992s
    user    0m1.364s
    sys     0m0.580s

    # with "files winbind"
    root at gumbo:~# time find /srv/svn/ -xdev \
                  '(' -nouser -o -nogroup ')' -printf x >x
    real    1m17.193s
    user    0m4.956s
    sys     0m4.508s

I haven't bothered trying sssd yet, because winbind worked.
But this slowdown freaks me out.

Is this normal for the samba4 AD/builtin winbind?
Should I report it to the samba BTS?

Is sssd noticably better in this respect?

The database is not unusually large:

    # ldbsearch -H tdb:///var/lib/samba/private/sam.ldb cn |
      grep -c ^dn:
    605

    # du -sh /var/lib/samba/private/
    60M     /var/lib/samba/private/