Re: [PATCH] sched/rt: Do not do push/pull when there is only one CPU

[Steven Rostedt]

On Sat, 2 Dec 2017 13:53:31 +0100
Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx> wrote:

> what about a check next to sched_feat(RT_PUSH_IPI)? I don't know if this
> is a hot path or not (due to bitmap_weight). If it is, then I would
> suggest something like a jump-label which is enabled if more than one
> CPU has been enabled on boot.

Yeah I didn't like that because of the overhead. But I was being
optimistic that the cpu weight function would be a nit to the actual
pull logic. But I have a better plan.

I would like to disable RT_PUSH_IPI, but that's a sched feature and
that is a constant if we build without sched debugging.

v2 coming up.

-- Steve