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SubjectRe: [RFC] Scheduler issue 1, RT tasks ...
>>>>> "George" == george anzinger <> writes:

George> Davide Libenzi wrote:
>> Local RT tasks apply POSIX priority rules inside the local CPU, that means
>> that an RT task running on CPU0 cannot preempt another task ( being it
>> normal or RT ) on CPU1.
>> Global RT tasks, that live in a separate run queue, have the ability to
>> preempt remote CPU and this can lead.
>> The local/global RT task selection is done with setscheduler() with a new
>> ( or'ed ) flag SCHED_RTGLOBAL, and this means that the default is RT task
>> local.

George> My understanding of the POSIX standard is the the highest priority
George> task(s) are to get the cpu(s) using the standard calls. If you want to
George> deviate from this I think the standard allows extensions, but they IMHO
George> should be requested, not the default, so I would turn your flag around
George> to force LOCAL, not GLOBAL.

I'd like to second that, IMHO the RT task scheduling should trade
throughput for latency, and if someone wants priority inversion, let
him explicitly request it.


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