how to determine kernel interrupt latency

[Peter Teoh]

never use any of the following software before....just suggest based on
reading online:

cyclictest:   read this:

http://www.spinics.net/lists/linux-rt-users/msg04088.html    (as explained
within, "timer interrupt latency" is what is being measured by
cyclictest.....not sure how it is done).

More on cyclictest:

http://elinux.org/images/0/01/Elc2013_rowand.pdf
http://people.redhat.com/williams/latency-howto/rt-latency-howto.txt
(last section on different ways of using cyclictest for interrupt latency
is covered.)

another:

https://github.com/atlas555/rt-test   (interrupt_tool)

another is "intrperf" which originate from FreeBSD but there is a Linux
version.   google for it  (
https://repos.dcl.info.waseda.ac.jp/spumone/trac/wiki/Interrupt%20Latency%20of%20Linux%20(intrperf)???).

As highlighted here:

http://marc.info/?l=linux-smp&m=102733872816465

interrupt latencies is really in such smaller order magnitude-wise, or due
to low-level CPU feature like I-cache

http://marc.info/?l=linux-arm-kernel&m=107472646713656

that it is not easy nor worth the time tuning.....may be I am wrong.

Check this for another discussion:

http://marc.info/?t=107403458800005&r=1&w=2

On Sun, Mar 16, 2014 at 9:09 PM, loody <miloody at gmail.com> wrote:

> hi peter:
>
>
> 2014-01-17 13:41 GMT+08:00 Peter Teoh <htmldeveloper at gmail.com>:
> >
> http://stackoverflow.com/questions/15383259/are-there-any-kernel-tools-available-to-measure-interrupt-latency-with-reasonabl
> >
> > checkout cyclictest.
> I have checked cyclictest.
> from manual page, it seems used to calculate thread latency instead of
> interrupt latency
> Would you please let me know if there any kind of command for using it
> to check interrupt latency ?
> thanks fo

-- 
Regards,
Peter Teoh
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