Re: Help: profiling the kernel module

[William C. <wc...@re...>]

On 10/25/2011 12:37 PM, Raghuramchary Jallipalli wrote:
> Ok.. This is the driver for the Xilinix based fpga PCIe device. The driver writes and reads the data to/from the device. The PCIe throughput values for write/read are not as expected, so I suspect there is a problem in my driver module. To triage this, I'm trying to profile my PCIe driver module hoping to get get a clue.
> 
> 
> Thanks Will.
> Raghu

Hi Raghu,

Thanks for the summary. It sound unlikely that the bottleneck is the processor. Oprofile is best showing where the processor hotspots are.

You might take a look at SystemTap for triaging the problem: http://sourceware.org/systemtap/

There are  some examples like latencytap.stp on http://sourceware.org/systemtap/examples/ that could give some ideas about what is causing the performance problem.

Also found new group thread discussing a similar problem:

http://www.linuxquestions.org/questions/linux-newbie-8/pcie-driver-need-high-performance-660222/

-Will