Re: [RFC PATCH 0/3] CFS idle injection

From	Jacob Pan <jacob.jun.pan@linux.intel.com>
Newsgroups	linux.kernel
Subject	Re: [RFC PATCH 0/3] CFS idle injection
Date	2015-11-09 15:40 +0100
Message-ID	<qsVLX-7E4-1@gated-at.bofh.it> (permalink)
References	(2 earlier) <qr9zH-2YD-7@gated-at.bofh.it> <qrpO9-5g9-1@gated-at.bofh.it> <qrSwO-71N-13@gated-at.bofh.it> <qrWh4-13l-15@gated-at.bofh.it> <qsTh8-5UJ-17@gated-at.bofh.it>
Organization	OTC

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On Mon, 09 Nov 2015 11:56:51 +0000
Punit Agrawal <punit.agrawal@arm.com> wrote:

> > actually, I was suggesting to start considering idle injection once
> > frequency capped to the energy efficient point, which can be much
> > higher than the lowest frequency. The idea being, deep idle power is
> > negligible compared to running power which allows near linear
> > power-perf scaling for balanced workload.
> > Below energy efficient frequency, continuous lowering frequency may
> > lose disproportion performance vs. power. i.e. worse than linear.
> >  
> 
> I agree. I was making that assumption that with the ability to inject
> idle states, there wouldn't be a need to expose the inefficient
> frequency states.
> 
> Do you still see a reason to do that?
yes, but it is up to a governor or management sw to decide when to to
pick what mechanism. there may be certain workload scale better with
frequency change. e.g. unbalanced workload, we don't want to inject
idle to all cpus if just one is busy. but it is also unlikely to run
into thermal issue in this case.
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Thread

[RFC PATCH 0/3] CFS idle injection Jacob Pan <jacob.jun.pan@linux.intel.com> - 2015-11-03 01:20 +0100
  [RFC PATCH 3/3] sched: introduce synchronized idle injection Jacob Pan <jacob.jun.pan@linux.intel.com> - 2015-11-03 01:20 +0100
    Re: [RFC PATCH 3/3] sched: introduce synchronized idle injection Peter Zijlstra <peterz@infradead.org> - 2015-11-03 14:40 +0100
      Re: [RFC PATCH 3/3] sched: introduce synchronized idle injection Jacob Pan <jacob.jun.pan@linux.intel.com> - 2015-11-03 15:20 +0100
      Re: [RFC PATCH 3/3] sched: introduce synchronized idle injection Jacob Pan <jacob.jun.pan@linux.intel.com> - 2015-11-03 17:50 +0100
        Re: [RFC PATCH 3/3] sched: introduce synchronized idle injection Peter Zijlstra <peterz@infradead.org> - 2015-11-05 11:20 +0100
          Re: [RFC PATCH 3/3] sched: introduce synchronized idle injection Arjan van de Ven <arjan@linux.intel.com> - 2015-11-05 15:30 +0100
            Re: [RFC PATCH 3/3] sched: introduce synchronized idle injection Peter Zijlstra <peterz@infradead.org> - 2015-11-05 15:40 +0100
              Re: [RFC PATCH 3/3] sched: introduce synchronized idle injection Peter Zijlstra <peterz@infradead.org> - 2015-11-05 15:50 +0100
              Re: [RFC PATCH 3/3] sched: introduce synchronized idle injection Arjan van de Ven <arjan@linux.intel.com> - 2015-11-05 16:30 +0100
                Re: [RFC PATCH 3/3] sched: introduce synchronized idle injection Peter Zijlstra <peterz@infradead.org> - 2015-11-05 18:00 +0100
                Re: [RFC PATCH 3/3] sched: introduce synchronized idle injection Thomas Gleixner <tglx@linutronix.de> - 2015-11-05 20:00 +0100
                Re: [RFC PATCH 3/3] sched: introduce synchronized idle injection Thomas Gleixner <tglx@linutronix.de> - 2015-11-05 19:50 +0100
              Re: [RFC PATCH 3/3] sched: introduce synchronized idle injection Jacob Pan <jacob.jun.pan@linux.intel.com> - 2015-11-05 16:40 +0100
                Re: [RFC PATCH 3/3] sched: introduce synchronized idle injection Arjan van de Ven <arjan@linux.intel.com> - 2015-11-05 17:10 +0100
          Re: [RFC PATCH 3/3] sched: introduce synchronized idle injection Jacob Pan <jacob.jun.pan@linux.intel.com> - 2015-11-05 20:30 +0100
            Re: [RFC PATCH 3/3] sched: introduce synchronized idle injection Jacob Pan <jacob.jun.pan@linux.intel.com> - 2015-11-05 20:40 +0100
      Re: [RFC PATCH 3/3] sched: introduce synchronized idle injection Peter Zijlstra <peterz@infradead.org> - 2015-11-05 15:10 +0100
        Re: [RFC PATCH 3/3] sched: introduce synchronized idle injection Jacob Pan <jacob.jun.pan@linux.intel.com> - 2015-11-06 00:50 +0100
          Re: [RFC PATCH 3/3] sched: introduce synchronized idle injection Peter Zijlstra <peterz@infradead.org> - 2015-11-06 08:50 +0100
            Re: [RFC PATCH 3/3] sched: introduce synchronized idle injection Jacob Pan <jacob.jun.pan@linux.intel.com> - 2015-11-07 01:00 +0100
              Re: [RFC PATCH 3/3] sched: introduce synchronized idle injection Jacob Pan <jacob.jun.pan@linux.intel.com> - 2015-11-10 01:30 +0100
  [RFC PATCH 2/3] timer: relax tick stop in idle entry Jacob Pan <jacob.jun.pan@linux.intel.com> - 2015-11-03 01:20 +0100
  Re: [RFC PATCH 0/3] CFS idle injection Eduardo Valentin <edubezval@gmail.com> - 2015-11-04 07:10 +0100
    Re: [RFC PATCH 0/3] CFS idle injection Jacob Pan <jacob.jun.pan@linux.intel.com> - 2015-11-04 18:00 +0100
      Re: [RFC PATCH 0/3] CFS idle injection Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> - 2015-11-04 18:10 +0100
        Re: [RFC PATCH 0/3] CFS idle injection Eduardo Valentin <edubezval@gmail.com> - 2015-11-04 19:50 +0100
      Re: [RFC PATCH 0/3] CFS idle injection Peter Zijlstra <peterz@infradead.org> - 2015-11-05 11:20 +0100
        Re: [RFC PATCH 0/3] CFS idle injection Punit Agrawal <punit.agrawal@arm.com> - 2015-11-06 18:00 +0100
          Re: [RFC PATCH 0/3] CFS idle injection Jacob Pan <jacob.jun.pan@linux.intel.com> - 2015-11-06 22:00 +0100
            Re: [RFC PATCH 0/3] CFS idle injection Punit Agrawal <punit.agrawal@arm.com> - 2015-11-09 13:00 +0100
              Re: [RFC PATCH 0/3] CFS idle injection Peter Zijlstra <peterz@infradead.org> - 2015-11-09 15:20 +0100
                Re: [RFC PATCH 0/3] CFS idle injection Jacob Pan <jacob.jun.pan@linux.intel.com> - 2015-11-09 15:50 +0100
                Re: [RFC PATCH 0/3] CFS idle injection Juri Lelli <juri.lelli@gmail.com> - 2015-11-10 11:10 +0100
                Re: [RFC PATCH 0/3] CFS idle injection Peter Zijlstra <peterz@infradead.org> - 2015-11-10 11:40 +0100
                Re: [RFC PATCH 0/3] CFS idle injection Juri Lelli <juri.lelli@arm.com> - 2015-11-10 12:00 +0100
              Re: [RFC PATCH 0/3] CFS idle injection Jacob Pan <jacob.jun.pan@linux.intel.com> - 2015-11-09 15:40 +0100
        Re: [RFC PATCH 0/3] CFS idle injection Dietmar Eggemann <dietmar.eggemann@arm.com> - 2015-11-06 19:40 +0100
          Re: [RFC PATCH 0/3] CFS idle injection Jacob Pan <jacob.jun.pan@linux.intel.com> - 2015-11-06 20:20 +0100
            Re: [RFC PATCH 0/3] CFS idle injection Dietmar Eggemann <dietmar.eggemann@arm.com> - 2015-11-06 23:00 +0100
              Re: [RFC PATCH 0/3] CFS idle injection Jacob Pan <jacob.jun.pan@linux.intel.com> - 2015-11-09 22:30 +0100
                Re: [RFC PATCH 0/3] CFS idle injection Peter Zijlstra <peterz@infradead.org> - 2015-11-09 22:50 +0100

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