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FreeRTOS context switching in V8.0.0

Posted by virgulap on June 28, 2017


could someone please clarify a point that I found in the change history of FreeRTOS revision?This point is regarding the context switching of task and is expressed in the history doc as: + Previously, when a task left the Blocked state, a context switch was performed if the priority of the unblocked task was greater than or equal to the priority of the Running task. Now a context switch is only performed if the priority of the unblocked task is greater than the priority of the Running task. My understanding is here that in case of task that have the same priority the Round Robin wont be possible anymore? Or am I wrong? So the specific question is, if updating to version V8.0.0 the current priorities of the task should be reorganized.

Thank you in advance!

FreeRTOS context switching in V8.0.0

Posted by richarddamon on June 28, 2017

From my understanding, Round Robin still happens. What is different is if you have two task of the same prioritty, if one of the tasks unblocks the other, for instance by posting to a queue, then before, the task that was unblocked would be switched to immediately, while with the change, not until the first task yields, blocks, or the time tick occurs. This gives the first task a better chance to get its full share of the processor.

FreeRTOS context switching in V8.0.0

Posted by virgulap on June 29, 2017

Thank you for your answear!It really helped!

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