On 04/07/2018 09:57 AM, Philippe Gerum wrote:
> On 04/06/2018 06:51 PM, C Smith wrote:
>> Hi all--
>> Our real time application has a main rt_task which runs concurrently with
>> several other rt_tasks (spawned using rt_task_create) and we are concerned
>> about a context switch in one of the tasks. The problematic task uses
>> libxml2 to parse an xml document sent over ethernet which seems to cause a
>> switch to secondary mode. Would this also switch the other tasks we are
>> running to secondary mode, or is it isolated?
> This is isolated in the sense that only the xml parser task will switch
> to secondary mode.
> However, this may still cause a priority inversion for any rt thread
> which synchronizes with that switching thread, since the former may end
> up waiting for a wake up event coming from the latter, which might be
> delayed until it switches back to rt mode.

Also, unwanted mode switches might cause runtime overhead when they
happen frequently enough. So it depends on how frequently the parser
task is switching out of rt mode.


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