RE: Performance issue - VoIP application on Linux 2.4.22

bobys wrote:

Hello everybody,
I have a multithreaded VoIP application in user space and a kernel

driver

module on MPC 8248 based board.
During media data transfer( Video Call) I have observed one strange
behavior
that at specific interval, cpu utilization is reaching to 100 % and

then

rolls back to 0 %.  This behavior repeats at regular intervals of time
during the call.
During this time, data rate and memory utilization is constant

throughout

the Call. Also number of interrupts received and processed in the

kernel

driver is constant.  We have checked the code many times, but couldn't

find

any of the threads/driver hogging the processor time.
We are using Linux kernel 2.4.22  with kernel preemption enabled and

low

latency patch added. Please let me know anybody have seen same behavior

and

how to sort this out.

I have no idea with 2.4.x. However, if you have OProfile[1] support
available in your kernel (look for custom module on 2.4), that's quite
easy=20
to spot the cpu utilization burst.

[1] http://oprofile.sf.net


Best Regards
--=20
Stephane

PS: OProfile is a neat tool. We won't thank enough the OProfile team.