Re: [Adeos-main] Latency trace on ARM

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

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Sebastian Smolorz wrote:
> Jan Kiszka wrote:
>> Sebastian Smolorz wrote:
>>> Hi,
>>>
>>> we all know that the latency test should not be run with a period of 100
>>> us because it easily gets locked up. The attached trace illustrates this
>>> problem in detail. It shows that a timer interrupt needs about 50 us to
>>> be processed. Furthermore, there is not enough time between two timer
>>> interrupts for the latency task to get all its work done.
>>>
>>> The current I-pipe tracer patch for ARM is available at
>>> http://opensource.emlix.com/ipipe-s3c24xx/download/ipipe-tracer-arm.patch
>>> _v4
>>>
>>> Comments welcome.
>> Something is still broken, given all those "N"s in Delay column. Is
>> there something like NMI at all on your board?
> 
> There isn't AFAIK. What could be the reason for all this noise? Recursive 
> spin-locking?

Yes. If those Ns aren't false positive in the sense that
IPIPE_TFLG_NMI_HIT is set accidentally, __ipipe_trace is re-entered
while IPIPE_TFLG_NMI_LOCK is still set.

Jan


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