Messages in this thread | | | Date | Tue, 11 Dec 2012 20:10:09 +0800 | Subject | Re: [RFC PATCH] sched: rt: fix selecting runqueue for task to be pushed | From | Hillf Danton <> |
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On Mon, Dec 10, 2012 at 10:21 PM, Steven Rostedt <rostedt@goodmis.org> wrote: > On Mon, 2012-12-10 at 20:19 +0800, Hillf Danton wrote: >> When we are trying to push task out, no point to select the last cpu that >> the given task executed on, which is fixed by selecting target cpu with >> cache affinity concerned, and with SD_WAKE_AFFINE ignored as we are not >> handling sleeper. > > I have to ask. Why? > > The check you are skipping is if the task is running on a CPU that is > already the lowest CPU priority (lowest_mask returns the CPUs running > tasks of the lowest priority in the system).
Hm ... how do you get the lowest mask for a pushable task iff that check makes sense?
> Which means that either the > task that we are pushing is the same priority or lesser priority than > what is running on the other CPUs. Either case, this task wont push out > a task on the other CPUs because it's not higher priority than those > tasks. > > You just added more work for the same result (no push). > > -- Steve > >
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