Re: [RFCv5 PATCH 35/46] sched: Disable energy-unfriendly nohz kicks

[Peter Zijlstra]

On Tue, Jul 07, 2015 at 07:24:18PM +0100, Morten Rasmussen wrote:
> With energy-aware scheduling enabled nohz_kick_needed() generates many
> nohz idle-balance kicks which lead to nothing when multiple tasks get
> packed on a single cpu to save energy. This causes unnecessary wake-ups
> and hence wastes energy. Make these conditions depend on !energy_aware()
> for now until the energy-aware nohz story gets sorted out.

The patch does slightly more; it also allows the kick if over utilized.

But disabling this will allow getting 'stuck' in certain over loaded
situations because we're not kicking the balancer.

I think you need more justification for doing this.

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/