Messages in this thread | | | Date | Tue, 4 Nov 2014 22:29:24 +0800 | Subject | Re: [PATCH v2 2/6] sched/rt: Optimize select_task_rq_rt() for non-RT curr task | From | "pang.xunlei" <> |
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On 4 November 2014 20:52, Steven Rostedt <rostedt@goodmis.org> wrote: > On Tue, 4 Nov 2014 19:13:01 +0800 > "pang.xunlei" <pang.xunlei@linaro.org> 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. Ok, thanks! But I think the PUSH operation optimized by the former patch is reasonable, since PUSH itselft does involve the Migration. Do I miss something?
> > Nack > > -- Steve >
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