| From | Valentin Schneider <> | Subject | Re: [PATCH 06/23] sched,psci: Convert to sched_set_fifo*() | Date | Wed, 22 Apr 2020 12:55:53 +0100 |
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On 22/04/20 12:27, Peter Zijlstra wrote: > Because SCHED_FIFO is a broken scheduler model (see previous patches) > take away the priority field, the kernel can't possibly make an > informed decision. > > Effectively changes prio from 99 to 50. > > XXX this thing is horrific, it basically open-codes a stop-machine and > idle. >
I went and tried to clean up the thing. I didn't find a clean way to use stop_machine() + play_idle() (stoppers can't sleep), but I did manage to get something usable with the existing FIFO threads, play_idle_precise() and the cpuidle state usage stats, so the whole homebrewed idle thing can go.
I also just tested it with 50 prio and big surprise it didn't change anything (it ends up being sibling of idle injection). So FWIW:
Acked-by: Valentin Schneider <valentin.schneider@arm.com>
> Cc: daniel.lezcano@linaro.org > Cc: sudeep.holla@arm.com > Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> > Reviewed-by: Ingo Molnar <mingo@kernel.org>
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