Re: Real-time scheduling policies and hyper-threading

[Roman Gushchin <klamm@yandex-team.ru>]

25.04.2014, 00:16, "Kirill Tkhai" <tkhai@yandex.ru>:
> 24.04.2014, 22:59, "Peter Zijlstra" <peterz@infradead.org>:
>
> [snip]
>
>>>   Does anyone use rt-scheduler for runtime-like cpu-bound tasks?
>>  So in general cpu bound tasks in the RT classes (FIFO/RR/DEADLINE) are
>>  bad and can make the system go funny.
>>
>>  For general system health it is important that various system tasks
>>  (kthreads usually) can run. Many of these kthreads run at !rt prios, and
>>  by having cpu bound tasks in rt prios they don't get to run.
>
> One more word to this. I had such expirience on 2.6.33 kernel with RT patch
> and weak hardware (sparc32).
>
> Networking was actively used and application did not use any IO operations.
>
> User needs to set all RT priorities by himself. It's necessary to set RT
> priorities at least for softirqs and rcus. RT bandwidth must be switched
> off.

I disable RT bandwidth sharing and change rt_period/rt_runtime to 1/100 ms
respectively.

Thanks,
Roman