Hi,
I have installed FC3(2.6.9).
I would like to improve my current kernel performance by customizing for my target application(ASTERISK).So,i disable all unneccessary drivers,enabled preemptive and successfully built the kernel.
then i tested/compared my application performance on both the kernels by putting load(running infinity loops parallelly ) and observed that my customized kernel giving better peformance.
But ...what are the parameters i have to scale to conclude and how?
is there any tools/application to test the kernel performance?
I think you understood me.
And suggest me the approches to improve kernel performance...
Any help appreciated!

Regards,
gangaraju

None of the changes you make will improve the kernel performance. They may however improve application performance. Before attempting changes, you need to understand where the primary constraint is. Is your application constrained on CPU, memory or I/O? The changes you make differ with the nature of the constraint. If there is no constraint, there is no benefit to tuning.

hi macemoneta,
Thank you for replying.
My goal is improve the application performance only.
My application ASTERISK should get maximum CPU time to maintain the stable link.Suggest me what are the changes i should make at OS level.
How would Custemizing the kernel(removing unneccessary stuff from the kernel) help me in this regard.

Removing uneccessary software will not improve CPU resource availability at all. The code is unused, so it uses no CPU resource. It may provide additional memory if the software being removed is part of the resident kernel. If the code being removed is normally a module, then there is no memory savings - if the module is not loaded, it uses no memory (or CPU, obviously).

There are changes that can be made to reduce latency as you've made with preempt, but that reduces available CPU cycles in exchange for faster access to the CPU. Asterisk does not require that as far as I have been able to determine.

There should be no tuning necessary (other than running the most recent 2.6 kernel possible). Asterisk has no requirement for user specified kernel tuning. If you are having a problem with dropped calls or other issues, I suggest that you post a question in a new thread on that specific issue.

There is also an Asterisk Forum that you may be able to find help in.

hi macemoneta,
The problem is...
When we try to open any application(like mozilla,lock screen,opeoffice...) while Asterisk was up and running with huge dialouts the link was geeting down (i.e missing interrupts).
And more our server is dual processor(Xeon) .
I think you understood me.

I tried with changing "nice" value of asterisk to -19(making real time priority),without xserver and observed performance was great!!.
But is it only solution?
How the kernel tuning help to me.
Is there is any ?
Please suggest me.