Eric Lee / linux-smarc-t335x-v3.2

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Commit 8e6598af3f35629c37249a610cf13e73f70db279

Authored by Peter Zijlstra
Committed by Ingo Molnar
1 parent 47fe38fcff
Exists in master and in 4 other branches v3.2_AM335xPSP_04.06.00.11, v3.2_NEWT335xPSP_04.06.00.11, v3.2_SBC_SMARTMEN, v3.2_SMARCT335xPSP_04.06.00.11

sched: Feature to disable APERF/MPERF cpu_power 

I suspect a feed-back loop between cpuidle and the aperf/mperf
cpu_power bits, where when we have idle C-states lower the ratio,
which leads to lower cpu_power and then less load, which generates
more idle time, etc..

Put in a knob to disable it.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

Showing 2 changed files with 15 additions and 2 deletions Side-by-side Diff

... ... @@ -3602,11 +3602,19 @@
3602 3602 unsigned long power = SCHED_LOAD_SCALE;
3603 3603 struct sched_group *sdg = sd->groups;
3604 3604  
3605   - power *= arch_scale_freq_power(sd, cpu);
  3605 + if (sched_feat(ARCH_POWER))
  3606 + power *= arch_scale_freq_power(sd, cpu);
  3607 + else
  3608 + power *= default_scale_freq_power(sd, cpu);
  3609 +
3606 3610 power >>= SCHED_LOAD_SHIFT;
3607 3611  
3608 3612 if ((sd->flags & SD_SHARE_CPUPOWER) && weight > 1) {
3609   - power *= arch_scale_smt_power(sd, cpu);
  3613 + if (sched_feat(ARCH_POWER))
  3614 + power *= arch_scale_smt_power(sd, cpu);
  3615 + else
  3616 + power *= default_scale_smt_power(sd, cpu);
  3617 +
3610 3618 power >>= SCHED_LOAD_SHIFT;
3611 3619 }
3612 3620  
kernel/sched_features.h
Diff comments   View file @ 8e6598a
... ... @@ -82,6 +82,11 @@
82 82 */
83 83 SCHED_FEAT(CACHE_HOT_BUDDY, 1)
84 84  
  85 +/*
  86 + * Use arch dependent cpu power functions
  87 + */
  88 +SCHED_FEAT(ARCH_POWER, 0)
  89 +
85 90 SCHED_FEAT(HRTICK, 0)
86 91 SCHED_FEAT(DOUBLE_TICK, 0)
87 92 SCHED_FEAT(LB_BIAS, 1)