[Samba] performance problems

[Bruno Gomes Pessanha]

My samba print server joined sucessfully to ADS domain is very slow. 100%
CPU usage.

I did a strace in smbd process:

# strace -p 4519 -cfqrT
% time     seconds  usecs/call     calls    errors syscall
------ ----------- ----------- --------- --------- ----------------
 76.37  359.200799         288   1249032       346 fcntl64
 11.61   54.605778         236    231636         4 read
  2.05    9.647553         224     43120           time
  1.60    7.503416         220     34140           _llseek
  1.11    5.240488         281     18658       209 select
  1.03    4.864289         291     16715        20 write
  0.64    3.008094         295     10188           gettimeofday
  0.63    2.981000         310      9622      1059 stat64
  0.59    2.790863         324      8606           close
  0.52    2.432799         298      8168           geteuid32
  0.51    2.419820         321      7549        14 open
  0.42    1.977740         314      6291           fstat64

The fcntl64 system call is taking a lot of CPU time. What did that mean?
Somebody could help me? I'm almost getting desperate... also 10.000 users.

Here it go:
Samba Version 3.0.22
RHEL 4 Update 3  - kernel 2.6.9-34.ELsmp
smb.conf
[global]
        workgroup = DOMAIN
        netbios name = printserver
        server string = PRINTSERVER Server
        security = ads
        realm = DOMAIN.BIZ
        password server = 10.163.200.101, 10.163.200.102, 10.163.200.103
        log file = /samba/var/smbd.log
        max log size = 50
        socket options = TCP_NODELAY SO_RCVBUF=8192 SO_SNDBUF=8192
        printcap name = /etc/printcap
        dns proxy = No
        wins server = 10.163.200.101, 10.163.200.102
        remote announce = 10.163.200.101, 10.163.200.102, 10.163.200.103
        remote browse sync = 10.163.200.101, 10.163.200.102, 10.163.200.103
        deadtime = 5
        keepalive = 30
        client schannel = no
        enable privileges = yes

        idmap uid = 1000-100000
        idmap gid = 1000-100000
        winbind cache time = 43200
        winbind use default domain = no
        winbind nested groups = yes
        winbind enum users = no
        winbind enum groups = no
        allow trusted domains = yes
        winbind separator = +

        printing = cups
        cups options = raw
        load printers = yes
        show add printer wizard = no
        printcap cache time = 0

[printers]
   comment = All Printers
   path = /var/spool/samba
   browseable = no
   guest ok = yes
   writable = no
   printable = yes

[print$]
   path = /samba/drivers
   public = yes
   writable = no
   browseable = yes


Thank you all in advance,

Bruno Gomes Pessanha