I have a AMD opteron linux (RHEL4 2.6.9-22.0.2.EL) system and am unable to initialize oprofile. I get the following message.
opcontrol --init
cat: /dev/oprofile/cpu_type: No such file or directory
Unable to open cpu_type file for reading
Make sure you have done opcontrol --init
cpu_type 'unset' is not valid
Following information maybe helpful.
 uname -a
Linux wauwinet 2.6.9-22.0.2.ELsmp #1 SMP Thu Jan 5 17:11:56 EST 2006 x86_64 x86_64 x86_64 GNU/Linux
opcontrol --version
opcontrol: oprofile 0.9.1 compiled on Aug  1 2006 16:41:22
rpm -qi oprofile
Name        : oprofile                     Relocations: (not relocatable)
Version     : 0.8.1                             Vendor: Red Hat, Inc.
Release     : 11                            Build Date: Fri 15 Oct 2004 03:24:41 PM EDT
Install Date: Sat 22 Jul 2006 12:31:01 AM EDT      Build Host: thor.perf.redhat.com
Group       : Development/System            Source RPM: oprofile-0.8.1-11.src.rpmSize        : 6106218                          License: GPL
Signature   : DSA/SHA1, Wed 20 Oct 2004 01:19:02 PM EDT, Key ID b44269d04f2a6fd2
Packager    : Red Hat, Inc. <http://bugzilla.redhat.com/bugzilla>
URL         : http://oprofile.sf.net
Summary     : System wide profiler for ix86 processors.
Description :
oprofile is a profiling system for x86 systems running Linux 2.2/2.4.
Profiling runs transparently during the background, and profile data
can be collected at any time. oprofile makes use of the hardware performance
counters provided on Intel P6, and AMD Athlon family processors, and can use
the RTC for profili ng on othe x86 processor types.
Please let me know if you need any more information. Any help would be greatly appreciated.