Dear Sir,
I re-started to test this again using RTEMS 5.0 lastest version. First of all, I am testing RTEMS for Realview PBX A9 on QEMU machine. As I check this on single core, example is working very well. Also, pthread priority value range is from 0 to 255. It is correct information. Because I use my real target(Cortex-A9) using RTEMS old version with SMP configuration, I would like to test RTEMS 5.0 version with SMP configuration. When I tested this on QEMU machine with “-smp 2” or “-smp 4”, S/W exception was occurred. Please let me know how to configure SMP for RealView PBX A9. Best Regards, JunBeom From: JunBeom Kim (EmbedCoreTech) <jb...@e-coretech.kr> Sent: Saturday, December 29, 2018 2:24 PM To: 'j...@rtems.org' <j...@rtems.org> Cc: '구철회' <ch...@kari.re.kr>; 'rtems-us...@rtems.org' <users@rtems.org> Subject: RE: RTEMS POSIX Priority Inversion Issue. Dear Joel, Thank you for your advice. I will check this from RTEMS 4.12 and RTEMS 5.0. After I check this, I will share update information. Have a good weekend and Happy new year. Best Regards, JunBeom From: Joel Sherrill <j...@rtems.org <mailto:j...@rtems.org> > Sent: Saturday, December 29, 2018 1:46 AM To: JunBeom Kim (EmbedCoreTech) <jb...@e-coretech.kr <mailto:jb...@e-coretech.kr> > Cc: 구철회 <ch...@kari.re.kr <mailto:ch...@kari.re.kr> >; rtems-us...@rtems.org <mailto:rtems-us...@rtems.org> <users@rtems.org <mailto:users@rtems.org> > Subject: Re: RTEMS POSIX Priority Inversion Issue. Hi I'm off for the holidays and answering from my phone. My suspicion is that the pthread command is an alias for the tasks command. Thus it is not reporting the priority from the view of the POSIX API but from the view of the Classic API. Internally all threads and tasks are instances of SuperCore threads and the priorities are mapped to what is required by the API. Priority 1 in Classic API is 254 in POSIX. Please investigate the code for the pthread command and see if I am right. This would be a minor bug in the shell rather than a priority inversion issue. --joel On Fri, Dec 28, 2018, 1:21 AM JunBeom Kim (EmbedCoreTech) <jb...@e-coretech.kr <mailto:jb...@e-coretech.kr> wrote: Dear Mr. Koo. There is not any relationship between main thread and pthread1/2/3. Main thread is run on core 1 of Cortex-A9. Pthread1/2/3 threads is run on core 2 of Cortex-A9. That is, both main thread and pthread1/2/3 is run on each cores independently. Also, I used manual affinity using pthread_setaffinity_np(). Pthread1/2/3 is created by main thread. and, actual operation is using Qt Thread API. I attached simple example code. Qt Thread API is calling RTEMS POSIX API. Best Regards, JunBeom From: ch...@kari.re.kr <mailto:ch...@kari.re.kr> <ch...@kari.re.kr <mailto:ch...@kari.re.kr> > Sent: Friday, December 28, 2018 4:05 PM To: JunBeom Kim (EmbedCoreTech) <jb...@e-coretech.kr <mailto:jb...@e-coretech.kr> > Cc: users@rtems.org <mailto:users@rtems.org> Subject: RE: RTEMS POSIX Priority Inversion Issue. 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 --------- 원본 메일 --------- 보낸사람 : "JunBeom Kim (EmbedCoreTech)" <jb...@e-coretech.kr <mailto:jb...@e-coretech.kr> > 받는사람 : <users@rtems.org <mailto:users@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: jb...@e-coretech.kr <mailto:jb...@e-coretech.kr> Web: www.e-coretech.kr <http://www.e-coretech.kr> ~~~~~~~~~~~~~~~~~~~~~~ <https://webmail.kari.re.kr:443/checkread/MTA2NjIz/amJraW1AZS1jb3JldGVjaC5rcg==/> _______________________________________________ users mailing list users@rtems.org <mailto:users@rtems.org> http://lists.rtems.org/mailman/listinfo/users
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