[CentOS] measuring kernel speed

Mon May 10 12:48:57 UTC 2010
JohnS <jses27 at gmail.com>

On Sun, 2010-05-09 at 11:38 -0400, Mag Gam wrote:
> This is an interesting topic.
> 
> So, how does one compare the kernel "speed"  from RT and Stock kernel?
> 
> Is there a benchmark I can use? For example (I know this is wrong):
> can I look at /proc/cpuinfo and look at the bogmips and compare and
> contrast?
> 
---
Please bottom post...or quote inline...

https://rt.wiki.kernel.org/index.php/Main_Page

http://www.latencytop.org/

/proc/cpuinfo and your bogomips is not going to give you what you want
in this respect.

In respect to speed there may different things to measure.  Like in the
rt-kernel your looking for the latency of the kernel and improving that.
Which that starts at the raw code layer before it is even compiled.  You
will never get good deterministic features from the kernel with out
that.  Then there is the filesystem your app is running on.

Like HL7 Messaging the speed facter comes from combining one maching
translating to sending to an upstream provider or sending it to another
host requiring further translation into a database.

Indeed the less kernel module space there is they say it performs faster
but i can't really see that.  Maybe someone with more experience will
comment on that for sure.  It don't seem to hold true when you allocate
a sole amount of memory to the kernel.

There is a patch required for the mainline kernel to run latencytop.
Oprofile looks promising also that Ross mentioned.

John