[Samba] groups command slow

[ZIGLIO, Frediano, VF-IT]

I want to thanks for improvements in winbindd. 3.0.25 is much faster.
Now I can log in my machine very fast.

I noted however that groups commands did not improve that much.
I used tcpdump to log ldap activity. The steps:
- winbind ask user groups (correct)
- winbind check groups updates (correct)
- winbind check all users in first user groups (asking for objectSid,
sAMAccountName, sAMAccountType and UserPrincipalName)... quite slow,
this query is IMHO not necessary and require more than 16.000 network
packets.

Frediano Ziglio