[Asterisk-Users] Interrupt latency problems

[Michael Welter]

Steven Critchfield wrote:

> top will only report userspace problems, and to top it off, top only
> reports on snapshots of the system on as low as 1 second. With Zap
> hardware hitting the system 1000 times a second for service, you might
> happen to get an occasional hit time here top and the hardware hit
> pretty close to show extra load. top also has the problem of effecting
> the system it is watching. It is a lot like those pesky physics problems
> where what you use to measure changes the object your measuring.
> 
> Basically all that is to say that top probably won't tell you what you
> want to know.About the only thing that would be of interest is if the
> percentage is viewed in the system or userspace portions. If in system,
> you will have to go debugging the kernel. 
> 
> Of course, it seems this is mostly being reported against RH and FC.
> I'll take a quick guess that it isn't bad users so it would leave you
> with bad kernels. My personal opinion is to not trust what the distros
> do to the kernels. Even in my beloved Debian I don't trust the default
> kernel. I suggest you download a stock vanila kernel from kernel.org and
> config it as minimally as possible for your hardware and try and see if
> it reproduces the problems you are seeing currently. 
>

In line #3 (CPU) of top, I'm seeing idle time go from 100% to +/-30% 
every 10 seconds.

I'll download 2.6.9 today and give it a try.

Thanks,



-- 
Michael Welter
Introspect Telephony Corp.
Denver, Colorado US
+1.303.674.2575
mike at introspect.com
www.introspect.com