RTEMS POSIX Priority Inversion Issue.

["구철회"]

What is the relation between main thread and pthread1/2/3?
If the main thread has a control to wake up each pthread1/2/3, it gonna be in trouble when the prioirty of the main thread is lower than pthread1/2/3s because the main thread has never chance to run it, which is required to other threads.


However why do you assign so much long integer value to priority?


Cheol


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보낸사람 : "JunBeom Kim (EmbedCoreTech)" <jbkim at e-coretech.kr>
받는사람 : <users at rtems.org>
받은날짜 : 2018-12-28 (금) 15:45:48
제목 : RTEMS POSIX Priority Inversion Issue.

 Dear Sir,   I am testing RTEMS POSIX thread priority. I am still using RTEMS 4.12 in 2017 year.   There are four pthreads(main, pthread1, pthread2, pthread3) on two cores in my test case. - main pthread is running on core 1. - pthread1, pthread2, pthread3 is running on core 2. - All threads are doing GPIO toggling action in while(1) loop. - my configuration for timeslice quantum is 25ms.   As I know from RTEMS POSIX manual, there is below statement.   In the RTEMS implementation of the POSIX API, the priorities range from the low priority of sched_get_priority_min() to the highest priority of sched_get_priority_max(). Numerically higher values represent higher priorities.   But, when I test this, lower value is doing as higher priority. Higher value is doing as lower priority. Is this correct operation ?   Case 0) All threads are same priority. [/] # pthread ID       NAME             CPU SHED PRI STATE  MODES    EVENTS WAITINFO ------------------------------------------------------------------------------ 0b010001  main_thread       1 MEDF 2147483645 READY P:T:nA   NONE   0b010002  pthread1           2 MEDF 2147483645 READY P:T:nA   NONE   0b010003  pthread2           2 MEDF 2147483645 READY P:T:nA   NONE   0b010004  pthread3           2 MEDF 2147483645 READY P:T:nA   NONE   Case 1) pthread3 is lower priority according to manual. But, pthread3 is higher priority in my case. [/] # pthread ID       NAME             CPU SHED PRI STATE  MODES    EVENTS WAITINFO ------------------------------------------------------------------------------ 0b010001  main_thread       1 MEDF 2147483645 READY P:T:nA   NONE   0b010002  pthread1           2 MEDF 2147483646 READY P:T:nA   NONE   0b010003  pthread2           2 MEDF 2147483646 READY P:T:nA   NONE   0b010004  pthread3           2 MEDF 1789569706 READY P:T:nA   NONE   Case 2) pthread3 is higher priority according to manual. pthread1 and pthread2 are higher priority than pthread3. [/] # pthread ID       NAME             CPU SHED PRI STATE  MODES    EVENTS WAITINFO ------------------------------------------------------------------------------ 0b010001  main_thread       1 MEDF 2147483645 READY P:T:nA   NONE   0b010002  pthread1           2 MEDF 1789569706 READY P:T:nA   NONE   0b010003  pthread2           2 MEDF 1789569706 READY P:T:nA   NONE   0b010004  pthread3           2 MEDF 2147483646 READY P:T:nA   NONE   Please advise.   Best Regards, JunBeom Kim ~~~~~~~~~~~~~~~~~~~~~~ President / EmbedCoreTech Phone: +82-31-396-5584 Fax: +82-504-065-5720 Mobile:+82-10-6425-5720 Email: jbkim at e-coretech.kr Web: www.e-coretech.kr ~~~~~~~~~~~~~~~~~~~~~~  
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