Re: [RFC PATCH 3/3] sched: introduce synchronized idle injection

From	Arjan van de Ven <arjan@linux.intel.com>
Newsgroups	linux.kernel
Subject	Re: [RFC PATCH 3/3] sched: introduce synchronized idle injection
Date	2015-11-05 15:30 +0100
Message-ID	<qrtI5-7PQ-1@gated-at.bofh.it> (permalink)
References	<qqxup-3IW-3@gated-at.bofh.it> <qqxuq-3IW-15@gated-at.bofh.it> <qqJYC-3iE-15@gated-at.bofh.it> <qqMWu-5jl-7@gated-at.bofh.it> <qrpOa-5g9-25@gated-at.bofh.it>
Organization	linux.* mail to news gateway

Show all headers | View raw

On 11/5/2015 2:09 AM, Peter Zijlstra wrote:

> 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.

idle injection is a last ditch effort in thermal management, before
this gets used the hardware already has clamped you to a low frequency,
reduced memory speeds, probably dimmed your screen etc etc.

at this point there are 3 choices
1) Shut off the device
2) do uncoordinated idle injection for 40% of the time
3) do coordinated idle injection for 5% of the time

as much as force injecting idle in a synchronized way sucks, the alternatives are worse.

>

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

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

csiph-web