Messages in this thread | | | Date | Thu, 5 Nov 2015 11:32:35 -0800 | From | Jacob Pan <> | Subject | Re: [RFC PATCH 3/3] sched: introduce synchronized idle injection |
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On Thu, 5 Nov 2015 11:27:32 -0800 Jacob Pan <jacob.jun.pan@linux.intel.com> wrote:
> On Thu, 5 Nov 2015 11:09:22 +0100 > Peter Zijlstra <peterz@infradead.org> wrote: > > > > Before: > > > CPU0 ______||| || |___________| || || |_____ > > > CPU1 _________||| || |_______| || |_______ > > > > > > After: > > > > > > CPU0 ______||| || |___________| || || |_____ > > > CPU1 ______||| || |___________| || |_______ > > > > > > The goal is to have overlapping idle time if the load is already > > > balanced. The energy saving can be significant. > > > > I can see such a scheme having a fairly big impact on latency, esp. > > with forced idleness such as this. That's not going to be popular > > for many workloads. > agreed, it would be for limited workload. the key is to identify such > workloads at runtime. I am thinking to use the load average of > the busiest CPU as reference for consolidation, will not go beyond > that. > For the patch I have today and if you play a game like this one > http://www.agame.com/game/cut-the-rope sorry, hit the wrong button before finishing the email. and set duration to 5, and 20% idle, it does not affect user experience much. It saves ~15% power on my BDW ultrabook. Other unbalanced workload such as video playback don't benefit, should be avoided.
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