Re: [Xenomai-core] [PATCH 0/3] NMI watchdog fixes / enhancements

[Jan Kiszka <jan.kiszka@domain.hid>]

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Gilles Chanteperdrix wrote:
> Jan Kiszka wrote:
>> This is basically a repost of the NNI watchdog series I sent out a few
>> weeks ago. I just rebased things over latest trunk and fixed some
>> warnings.
>>
>> All patches are also available at
>> git://git.kiszka.org/xenomai.git nmi-wd-queue
> 
> That is a lot of stuff to review. I am afraid it is impossible to review
> everything, so the only thing we can rely on is testing, hence the next
> question: have these patches been tested in every configuration
> (enabled, disabled, built-in, module, voluntary overrun)?

In most configurations, but definitely not in all (they are too many).

This is a debugging tool, so first of all the disabled case must not
cause harm, and I'm quite sure I haven't changed anything regarding
this. Moreover, the enabled case was not working for many recent
platforms anymore as we were lacking P6 support. So there shouldn't be
much to loose.

> 
> As for the 32nd bit issue, I am afraid it can not explain the spurious
> shots observed on some platfomrs (note that I implemented the early shot
> thing a bit in the dark: I never observed the spurious shots myself),
> that is because the nmi timer is programmed for durations between 100us
> and 10ms, which should be far from using the 32nd bit.

Yes, the signedness issue that is fixed in patch 1 has likely nothing to
do with the spurious invocations. But wherever they may still come from,
patch 3 ensures that they are now properly ignored (ie. forwarded to the
next handling instance).

Jan


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