On 21/08/2020 11:54, Richi Dubey wrote:
No, this would be completely wrong. You should never call
_Thread_Dispatch_enable(other_cpu) and you should never modify the
thread dispatch level inside the scheduler code. The only thing
you can
do is to update the heir and send requests via an inter-processor
interrupt.
Okay. So, to deal with the unpredictable time is it okay if I use heir
instead of executing in the following place (my aim is to get the
latest executing thread / to be executed thread on a cpu):
https://github.com/richidubey/rtems/blob/03d08d02b3e61570f2022845caa44ec6a261f677/cpukit/score/src/schedulerstrongapa.c#L243
https://github.com/richidubey/rtems/blob/03d08d02b3e61570f2022845caa44ec6a261f677/cpukit/score/src/schedulerstrongapa.c#L467
https://github.com/richidubey/rtems/blob/03d08d02b3e61570f2022845caa44ec6a261f677/cpukit/score/src/schedulerstrongapa.c#L248
In an SMP system you have to be very careful in which context you access
which data. We definitely lack some formalized way to document this. You
must not use the per-processor variables in your scheduler code. This
would be completely wrong. For the scheduler it doesn't matter if the
threads actually execute or not. The scheduler should use the chain of
scheduled nodes to maintain the node to processor allocation.
_______________________________________________
devel mailing list
devel@rtems.org
http://lists.rtems.org/mailman/listinfo/devel
