No useful callgraphs on Fedora 27

Hi,

I would like to use oprofile to analyze some interaction between a poor
performing graphical program and the Xorg x-server.
I know the function which consumes most of the cpu cycles (fbBltOne),
and a callstack could help to diagnose which X11 protocol request
causes this behaviour.

However on fedora 27, despite having all the debuginfo-packages
installed, I don't get a useful callgraph:


CPU: AMD64 family15h, speed 4000 MHz (estimated)
Counted CPU_CLK_UNHALTED events (CPU Clocks not Halted) with a unit
mask of 0x00 (No unit mask) count 100000
samples  %        image name               symbol name
-------------------------------------------------------------------------------
167267   37.1351  libfb.so                 fbBltOne
  167267   100.000  libfb.so                 fbBltOne [self]
-------------------------------------------------------------------------------
45871    10.1839  libc-2.26.so             __memcpy_ssse3
  45871    100.000  libc-2.26.so             __memcpy_ssse3 [self]
-------------------------------------------------------------------------------
17944     3.9838  kallsyms                 copy_user_generic_string
  17944    100.000  kallsyms                 copy_user_generic_string [self]
-------------------------------------------------------------------------------

Any ideas what could be wrong with my system?

Thank you in advance & best regards, Clemens

PS: Sorry for the cross-post (sysprof mailing list), I posted there
before I realized there isn't much traffic going on.

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