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Re: Thread activation disturbed by lower priority threads]


Hi,

thanks you definitely pointed me into the right direction. The problem is located with the mutexes. I removed all mutexes in questions and set my timing measurement points directly after the semaphore that is in charge of activating my threads.After making more measurements and playing a little bit around I found it that when I set the priority inversion protocol to none (using cyg_mutex_set_protocol). The timing is as expected. So I thought it could be that before I was using priority ceiling which would be an explanation for the delay as every time a mutex is gathered the thread will get priorty 0. So I changed to priority inheritance. This from my point of view should do the job as I like to have it done.
But when using priority inheritance I get the same bad timing as in the beginning.


And as longer I think I don't know why the tread activation of the highest priority thread is prolonged by threads holding a mutex with priority inheritance where each of the treads that my also get this mutex has a lower priority. So I'm completly confuesed. Any Ideas what could be the problem or what I could do?

For my current tests no priority inversion protocol is just fine, but for further more complected tests I think i will need something like priority inheritance so it would be nice to have it.

Thanks,
Alois

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