couldn't get kernel profiling data from OProfile

couldn't get kernel profiling data from OProfile

[Kirill Kuvaldin]

Hi,

I'm using oprofile 0.9.3 on Debian Lenny, kernel 2.6.22 SMP x86_64.

The problem I'm dealing with is that opreport couldn't provide
profiling data for the kernel image.

I start the profiler as follows, specifying the vmlinux image:

kkuvaldin@002:oprofile% sudo opcontrol --vmlinux=/boot/vmlinux
kkuvaldin@002:oprofile% sudo opcontrol --start
Using default event: CPU_CLK_UNHALTED:100000:0:1:1
Using 2.6+ OProfile kernel interface.
Reading module info.
Using log file /var/lib/oprofile/samples/oprofiled.log
Daemon started.
Profiler running.

Then I did some workload to make sure oprofile gets enough samples:

kkuvaldin@002:oprofile% dd if=/dev/urandom of=/dev/null
80870+0 records in
80869+0 records out
41404928 bytes (41 MB) copied, 6.04975 seconds, 6.8 MB/s

kkuvaldin@002:oprofile% sudo opcontrol --stop
Stopping profiling.

However when I tried to get some profiling data for the kernel binary,
I ended up with the following:

kkuvaldin@002:oprofile% sudo opreport -l /boot/vmlinux
error: no sample files found: profile specification too strict ?
zsh: exit 1     sudo opreport -l /boot/vmlinux


I double checked that /boot/vmlinux is the exact image that was
running on the system.


Any ideas why oprofile doesn't list samples for the vmlinux image?



Thanks,
Kirill