Got 'unknown' in oprofile/xenoprofile report

[Joe H. <joe...@gm...>]

Hi,
I'm using oprofile 0.9.5 with xenoprofile patch. I did some passive
profiling and noticed 'xen-unknown' in my report but don't have a clue
how to explain it.

Host OpenSuse 11.1, kernel 2.6.27.37, xen 3.3.1
Guest OpenSuse 11.1, kernel 2.6.27.29

Commands issued:
Dom0> opcontrol --reset
Dom0>  opcontrol --start-daemon
--xen=/boot/xen-syms-3.3.1_18546_20-0.1.1
--vmlinux=/boot/vmlinux-2.6.27.37-0.1-xen --passive-domains=1
--passive-images=/boot/vmlinux-2.6.27.29-0.1-xen-Dom1
Dom0> opcontrol --start
Then do something
Dom0> opcontrol --shutdown
Dom0> opreport > myreport

part of myreport:

CPU: Core 2, speed 2660.08 MHz (estimated)
Counted CPU_CLK_UNHALTED events (Clock cycles when not halted) with a
unit mask of 0x00 (Unhalted core cycles) count 1000000
CPU_CLK_UNHALT...|
  samples|      %|
------------------
     6609 35.0053 domain1-kernel
     4795 25.3972 domain1-xen
     4229 22.3994 domain1-apps
      458  2.4258 vmlinux-2.6.27.37-0.1-xen
      358  1.8962 domain1-xen-unknown
      208  1.1017 domain1-modules
      193  1.0222 xen-syms-3.3.1_18546_20-0.1.1
       24  0.1271 xen-unknown
......

How can these 'XX-unknown' come?
358  1.8962 domain1-xen-unknown
and
24  0.1271 xen-unknown

Do i miss some image or symbol names which I should pass to opcontrol?

cat /var/lib/oprofile/sampels/oprofiled.log
----
oprofiled started Mon Nov 30 10:58:34 2009
kernel pointer size: 8

Mon Nov 30 10:58:59 2009


-- OProfile Statistics --
Nr. sample dumps: 4
Nr. non-backtrace samples: 18788
Nr. kernel samples: 4729
Nr. lost samples (no kernel/user): 0
Nr. lost kernel samples: 0
Nr. incomplete code structs: 0
Nr. samples lost due to sample file open failure: 0
Nr. samples lost due to no permanent mapping: 0
Nr. event lost due to buffer overflow: 0
Nr. samples lost due to no mapping: 1
Nr. backtraces skipped due to no file mapping: 0
Nr. samples lost due to no mm: 0

---- Statistics for cpu : 1
Nr. samples lost cpu buffer overflow: 0
Nr. samples received: 18882
Nr. backtrace aborted: 0
Nr. samples lost invalid pc: 0

---- Statistics for cpu : 0
Nr. samples lost cpu buffer overflow: 0
Nr. samples received: 0
Nr. backtrace aborted: 0
Nr. samples lost invalid pc: 0
oprofiled stopped Mon Nov 30 10:58:59 2009

----

Thanks in advance.

-- 
Joe H