Re: [PATCH 3/4] sched: introduce synchronized idle injection

[Jacob Pan <jacob.jun.pan@linux.intel.com>]

On Fri, 20 Nov 2015 11:58:12 +0100 (CET)
Thomas Gleixner <tglx@linutronix.de> wrote:

> 	 if (machine_on_fire) {
Just to add data to show this is not just for emergency. I have an
broadwell laptop, here is the test I did.
- clamp cpu freq to 900MHz (close to max efficiency)
- run gpu and cpu load (cut-the-rop, glxgears)
- turn fans off

run tmon (tools/thermal/tmon) to show temperatures and thermal trip
points. (sorry about the long lines, quite  a few thermal sensors)
Also run turbostat to show CPU idle etc.

Observations:
without idle injection:
------------------------------------------------------------------
- package temp rise to 66C crossing the second active trip points
	(2nd fan speed should kick in if not disabled)
- package power 9.47w
- cpu c0 ~90%, 0% core c7
------------------------------------------------------------------
- with idle injection 20%
- cpu c0 ~67%, ~13% core c7, ~7% package c-states
- package power 4.53w
- package temp 52C

glxgears maintains the same frame rate. didnt measure cut-the-rope
but still plays.

This is a large 14 inch laptop with much better cooling than a fanless
tablet/convertible. So hitting thermal constraints can happen in _NORMAL_
condition (even at 900MHz), not just on fire case.

Sync up idle can save energy efficiency and i think scheduler is a better
place to solve that problem, perhaps with PM QoS constraint will have less
perceived intrusive behavior.

Thanks,

Jacob
 

│Trip Points:                   AAAAC       C                       AAPHCPP     APHCPP      PHCPP       AAPHCPP     AAAAPHCPP   APHCPP      AAAAPHC     PP                                                                                                    │
└─────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────┘
┌──────────────────────────────────────────────────────────────────────────────────────────────────────────── COOLING DEVICES ────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────┐
│ID  Cooling Dev   Cur    Max   Thermal Zone Binding                                                                                                                                                                                                          │
│00         TFN1     4     11   │││││││││││ │││││││││││ │││││││││││ │││││││││││ │││││││││││ │││││││││││ │││││││││││ │││││││││││ │││││││││││ │││││││││││ ││││││││││││                                                                                          │
│01          Fan     0      1   │││*│││││││ │││││││││││ │││││││││││ │││││││││││ │││││││││││ │││││││││││ │││││││││││ │││││││││││ │││││││││││ │││││││││││ ││││││││││││                                                                                          │
│02          Fan     0      1   ││*││││││││ │││││││││││ │││││││││││ │││││││││││ │││││││││││ │││││││││││ │││││││││││ │││││││││││ │││││││││││ │││││││││││ ││││││││││││                                                                                          │
│03          Fan     0      1   │*│││││││││ │││││││││││ │││││││││││ │││││││││││ │││││││││││ │││││││││││ │││││││││││ │││││││││││ │││││││││││ │││││││││││ ││││││││││││                                                                                          │
│04          Fan     0      1   *││││││││││ │││││││││││ │││││││││││ │││││││││││ │││││││││││ │││││││││││ │││││││││││ │││││││││││ │││││││││││ │││││││││││ ││││││││││││                                                                                          │
│05         CHRG     4      4   │││││││││││ │││││││││││ │││││││││││ │││││││││││ │││││││││││ │││││││││││ │││││││││││ │││││││││││ │││││││││││ │││││││││││ ││││││││││││                                                                                          │
│06 intel_powerc    -1     50   │││││││││││ │││││││││││ │││││││││││ │││││││││││ │││││││││││ │││││││││││ │││││││││││ │││││││││││ │││││││││││ │││││││││││ ││││││││││││                                                                                          │
└─────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────┘
┌─────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────┐
│                         10        20        30        40        50        60        70        80        90        100       110       120                                                                                                                   │
│acpitz 0:[ 66][→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→A55→→→→→→→A65       A75       A85                       C111          ]                                                                                                                │
│pch_wi 1:[ 59][→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→                                                       C115      ]                                                                                                                │
│INT340 2:[ 20][→→→→→→→→→→→→→→→→→→→→→                                                                                                        ]                                                                                                                │
│  SEN1 3:[ 47][P0→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→          A58  A63     P71                          H100103                  ]                                                                                                                │
│  SEN2 4:[ 51][P0→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→           A63     P71                          H100103                  ]                                                                                                                │
│  SEN3 5:[ 46][P0→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→                        P71                          H100103                  ]                                                                                                                │
│  SEN4 6:[ 45][P0→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→            A58  A63     P71                          H100103                  ]                                                                                                                │
│  SEN6 7:[ 46][P0→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→ A48  A53  A58  A63     P71                          H100103                  ]                                                                                                                │
│  SEN7 8:[ 27][P0→→→→→→→→→→→→→→→→→→→→→→→→→→                                   A63     P71                          H100103                  ]                                                                                                                │
│  B0D4 9:[ 66][→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→A55→→→→→→→A65       A75       A85              P102045                ]                                                                                                                │
│x86_pk10:[ 66][P0→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→→                                                          ]                                                                                                                │
└─────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────┘
turbostat without idle injection
      1       3     776   86.37     898    2295       0   11.90
    Core     CPU Avg_MHz   %Busy Bzy_MHz TSC_MHz     SMI  CPU%c1  CPU%c3  CPU%c6  CPU%c7 CoreTmp  PkgTmp Pkg%pc2 Pkg%pc3 Pkg%pc6 Pkg%pc7 Pkg%pc8 Pkg%pc9 Pk%pc10 PkgWatt CorWatt GFXWatt
       -       -     801   89.16     898    2295       0    9.77    0.55    0.07    0.44      66      70    0.00    0.00    0.00    0.00    0.00    0.00    0.00    9.47    4.31    1.17
       0       0     801   89.26     898    2294       0    9.76    0.57    0.07    0.34      64      70    0.00    0.00    0.00    0.00    0.00    0.00    0.00    9.47    4.31    1.17
       0       2     803   89.43     898    2294       0    9.58
       1       1     810   90.27     898    2295       0    8.59    0.52    0.07    0.55      66
       1       3     787   87.69     898    2295       0   11.17

turbostat with 20% idle injection
    Core     CPU Avg_MHz   %Busy Bzy_MHz TSC_MHz     SMI  CPU%c1  CPU%c3  CPU%c6  CPU%c7 CoreTmp  PkgTmp Pkg%pc2 Pkg%pc3 Pkg%pc6 Pkg%pc7 Pkg%pc8 Pkg%pc9 Pk%pc10 PkgWatt CorWatt GFXWatt
       -       -     601   66.92     898    2295       0   13.48    4.65    1.09   13.86      52      52    3.50    0.60    0.46    2.30    0.00    0.00    0.00    4.53    1.99    0.17
       0       0     605   67.36     898    2294       0   12.75    5.95    1.51   12.42      51      52    3.50    0.60    0.46    2.30    0.00    0.00    0.00    4.53    1.99    0.17
       0       2     583   64.94     898    2295       0   15.18
       1       1     605   67.37     898    2295       0   13.31    3.34    0.67   15.30      52
       1       3     611   68.02     898    2295       0   12.66

~                                                                                                                                                                                                                                                              
~                                                                                                                                                                                                                                                              
~                                                                                                                                                             

> 	        defer_timer_interrupt(5ms);
> 		end = now + 5ms:
> 	    	while (now < end)
> 		      mwait();
>          }

[Jacob Pan]