I am trying to profile a Linux kernel driver and I would like to find out how much CPUcycles/time spent in certain functions. My goal is not to identify the Hotspots in the system but to profile a particular driver function. I have loaded the kernel debug symbols as explained in this article. I can see Kernel functions under [vmlinux] but I can't see the functions that I'm interested in. I think the reason for that is my functions are much faster than the sampling rate. To prove this theory I forced the driver to execute very long operations and the functions started to show in the report but this is not the condition I would like to test.
Is there anyway to increase the sampling rate and/or to limit the trace to particular functions?
The system I'm using:
- VTune Amplifier XE 2015
- Distribution: Fedora 21
- Kernel: 3.19.3-200.fc21.x86_64
Thanks in advance.
-Tarek