Re: [PATCH v2 2/6] sched/rt: Optimize select_task_rq_rt() for non-RT curr task

[Steven Rostedt]

On Tue,  4 Nov 2014 19:13:01 +0800
"pang.xunlei" <pang.xunlei@xxxxxxxxxx> wrote:

> When selecting the cpu for a waking RT task, if curr is a non-RT
> task which is bound only on this cpu, then we can give it a chance
> to select a different cpu(definitely an idle cpu if existing) for
> the RT task to avoid curr starving.

Absolutely not! An RT task doesn't give a crap if a non RT task is
bound to a CPU or not. We are not going to migrate an RT task to be
nice to a bounded non-RT task.

Migration is not cheap. It causes cache misses and TLB flushes. This is
not something that should be taken lightly.

Nack

-- Steve

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