ISR Latency (was ISR Misses Interrupts)

QNX Newsgroups (Archives) qdn.public.qnxrtp.os
1

Just a note to comment on the resolution of the problem. The extraordinary
scheduling latency I had problems with was caused an application error,
rather than by the processor SMM. It was due to an unused timer running with
no consumer for its pulses. Apparently that causes the kernel to traverse
through some long lists. I’ve seen mistakes like that in the past that
generate a “work-panic” type error from the kernel. It seems QNX is happy to
continue no matter how long it takes to work through a list. Oh well, live
and learn.

Regards and thanks to all for your various suggestions.

Dave Kuechenmeister

2

David Kuechenmeister wrote:

It seems QNX is happy to
continue no matter how long it takes to work through a list. Oh well, live
and learn.

Thanks for following up with the resolution.

3

David Kuechenmeister <david.kuechenmeister@viasat.com> wrote:

Just a note to comment on the resolution of the problem. The extraordinary
scheduling latency I had problems with was caused an application error,
rather than by the processor SMM. It was due to an unused timer running with
no consumer for its pulses. Apparently that causes the kernel to traverse
through some long lists. I’ve seen mistakes like that in the past that
generate a “work-panic” type error from the kernel. It seems QNX is happy to
continue no matter how long it takes to work through a list. Oh well, live
and learn.

There is an outstanding PR against this issue. It isn’t an easy
one to resolve, though.

-David

QNX Training Services
http://www.qnx.com/support/training/
Please followup in this newsgroup if you have further questions.

4

Wind River has a list of outstanding bugs for each OS version posted on
their website. Is there a list of outstanding PRs for QNX available
anywhere?

Thanks,

“David Gibbs” <dagibbs@qnx.com> wrote in message
news:b1n0kd$lg0$1@nntp.qnx.com…

David Kuechenmeister <> david.kuechenmeister@viasat.com> > wrote:
Just a note to comment on the resolution of the problem. The
extraordinary
scheduling latency I had problems with was caused an application error,
rather than by the processor SMM. It was due to an unused timer running
with
no consumer for its pulses. Apparently that causes the kernel to
traverse
through some long lists. I’ve seen mistakes like that in the past that
generate a “work-panic” type error from the kernel. It seems QNX is
happy to
continue no matter how long it takes to work through a list. Oh well,
live
and learn.

There is an outstanding PR against this issue. It isn’t an easy
one to resolve, though.

-David

QNX Training Services
http://www.qnx.com/support/training/
Please followup in this newsgroup if you have further questions.