Add hotplug limitation to certain # of cores about android_kernel_elephone_p8000

[walter79]

CONFIG_NR_CPUS=8
(= 8 cores)

CONFIG_NR_CPUS=4
(= 4 cores)

https://github.com/visi0nary/android_kernel_elephone_p8000/blob/cm-12.1/arch/arm64/configs/p8000_cyanogenmod12_1_defconfig#L274

[janengelmohr]

Nice!

[walter79]

[B]Hotplug settings:[/B]

found here: /kernel/elephone/p8000/drivers/misc/mediatek/mach/mt6735/include/mach/mt_hotplug_strategy_internal.h

[CODE]
#define HPS_TASK_PRIORITY (MAX_RT_PRIO - 3)
#define HPS_TIMER_INTERVAL_MS (100)

#define MAX_CPU_UP_TIMES (10)
#define MAX_CPU_DOWN_TIMES (100)
#define MAX_TLP_TIMES (10)
//cpu capability of big / little = 1.7, aka 170, 170 - 100 = 70
#define CPU_DMIPS_BIG_LITTLE_DIFF (70)

/*

• CONFIG - runtime
• Execute time interval : 100 ms
  */
  #define DEF_CPU_UP_THRESHOLD (95)
  #define DEF_CPU_UP_TIMES (2)
  #define DEF_CPU_DOWN_THRESHOLD (85)
  #define DEF_CPU_DOWN_TIMES (8)
  #define DEF_TLP_TIMES (1)

#define EN_CPU_INPUT_BOOST (1)
#define DEF_CPU_INPUT_BOOST_CPU_NUM (2)

#define EN_CPU_RUSH_BOOST (1)
#define DEF_CPU_RUSH_BOOST_THRESHOLD (98)
#define DEF_CPU_RUSH_BOOST_TIMES (1)

#define EN_HPS_LOG (1)
#define EN_ISR_LOG (0)

/*

• EARLY SYSPEND CONFIG - runtime
• Execute time interval : 400 ms
  */
  #define DEF_ES_CPU_UP_THRESHOLD (95)
  #define DEF_ES_CPU_UP_TIMES (1)
  #define DEF_ES_CPU_DOWN_THRESHOLD (85)
  #define DEF_ES_CPU_DOWN_TIMES (2)
  [/CODE]

Found this: /kernel/elephone/p8000/drivers/misc/mediatek/mach/mt6735/mt_hotplug_strategy_main.c

[CODE]
//In order to fast screen on, power on extra little CPU to serve system resume.
little_cpu_num_resume = 4;
[/CODE]

[walter79]

This works well but need some improvement in cpu governor

little_cpu_num_resume = 1

#define EN_CPU_INPUT_BOOST (0)

#define EN_CPU_RUSH_BOOST (0)

[janengelmohr]

Closed because it limits hotplugging to a reasonable amount