[Samba] Access Samba share very slow

[yudi shiddiq]

Hai all, need help please,

I have samba server with version samba-3.2.6-1, authenticate to samba PDC.
I have spent 1 week to find the problem, all users which access to samba server move very..very slow, 
i have try to change SO_RCVBUF from 8192 to 4096 but there's no effect at all, so i turned it back to 8192, try to edit smb.conf for loging to just rename,unlink,rmdir,pwrite and open. but there's no effect too. 

When i try to save file *.ods file with size 71Kb it takes about 40second, and on top command the CPU usage is consume resource almost 100%:
Cpu0  :  2.7% us, 97.3% sy,  0.0% ni,  0.0% id,  0.0% wa,  0.0% hi,  0.0% si
Cpu1  :  0.0% us,  0.7% sy,  0.0% ni, 99.3% id,  0.0% wa,  0.0% hi,  0.0% si
Cpu2  :  0.0% us,  0.3% sy,  0.0% ni, 97.0% id,  2.6% wa,  0.0% hi,  0.0% si
Cpu3  :  4.3% us,  3.7% sy,  0.0% ni, 92.0% id,  0.0% wa,  0.0% hi,  0.0% si

This is my smb.conf

[global]
        netbios name = sambaserver3
        os level = 20
        preferred master = no
        security = user
        workgroup = SERVER
        hosts allow = 10.10.0.0/255.255.0.0
        encrypt passwords = yes
        ldap passwd sync = yes
        passdb backend = ldapsam:ldap://10.10.0.100
        lanman auth = yes
        smb ports = 139 445

        dos filemode = yes
        getwd cache = yes
        socket options = TCP_NODELAY SO_RCVBUF=8192 SO_SNDBUF=8192
        unix extensions = no
        wide links = yes
        wins support = no

        ##################################
        # Defining logging facility      #
        ##################################
        log file = /var/log/samba/%m.log
        log level = 1 vfs:0

        ### These enable symlinks ###
        # follow symlinks = yes

        ##################################
        # OpenLDAP stuff is defined here #
        ##################################

        ldap ssl = no
        ldap suffix = dc=sambaserver,dc=id
        ldap admin dn = cn=Manager,dc=sambaserver,dc=id
        ldap user suffix = ou=Users
        ldap machine suffix = ou=Computers
        ldap group suffix = ou=Groups
        ldap idmap suffix = ou=Users
idmap uid = 10000-20000
idmap gid = 10000-20000

template shell = /bin/false
winbind use default domain = no

        ########### Autodesk/Autocad things ###########
        csc policy = disable
        force security mode = 777
        nt acl support = no


[sys]
        path = (path share)
        comment = sambaserver
        level2 oplocks = no
        oplocks = no
        browseable = yes
        read only = no
        writable = yes
        create mode = 0775
        directory mode = 0777
        vfs objects = full_audit
        veto files = /*.mp3/*.MP3
        full_audit:failure = none
        full_audit:success = mkdir rename unlink rmdir pwrite write open
        full_audit:prefix = %u|%I|%m