라즈베리 저전력 관련 설정

Edit /boot/cmdline.txt and add maxcpus=N

[링크 : https://www.raspberrypi.org/forums/viewtopic.php?f=29&t=99372]

[링크 : https://www.raspberrypi.org/forums/viewtopic.php?t=152692]

USB 허브 끄기 - 단, 네트워크도 죽어버림(그럼 도대체 어떻게 쓰란거지 -ㅁ-?)

#!/bin/bash #Code to stop /etc/init.d/networking stop echo 0 > /sys/devices/platform/bcm2708_usb/buspower; echo “Bus power stopping” #!/bin/bash #Code to start echo 1 > /sys/devices/platform/bcm2708_usb/buspower; echo “Bus power starting” sleep 2; /etc/init.d/networking start

video output 끄기

This tip has been suggested by many people. If your system is headless (no video output) you can turn off the HDMI port with: sudo /opt/vc/bin/tvservice -o to turn it back on: sudo /opt/vc/bin/tvservice -p This command will save you around 20-30mA.

[링크 : https://babaawesam.com/2014/01/24/power-saving-tips-for-raspberry-pi/]

/sys/devices/system/cpu/cpu0/online 이 있으면 논리적으로 on/off 가능하다는데

라즈베리에는 

/sys/devices/system/cpu/online

/sys/devices/system/cpu/offline 만 존재한다.

[링크 : https://stackoverflow.com/questions/44907731/programmatically-disable-cpu-core]

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$ chcpu Usage:  chcpu [options] Options:   -h, --help                    print this help   -e, --enable <cpu-list>       enable cpus   -d, --disable <cpu-list>      disable cpus   -c, --configure <cpu-list>    configure cpus   -g, --deconfigure <cpu-list>  deconfigure cpus   -p, --dispatch <mode>         set dispatching mode   -r, --rescan                  trigger rescan of cpus   -V, --version                 output version information and exit

라즈베리에서는 안되네..

$ sudo chcpu -r chcpu: This system does not support rescanning of CPUs $ sudo chcpu -e 2 chcpu: CPU 2 is not hot pluggable

[링크 : https://www.ibm.com/support/knowledgecenter/en/linuxonibm/com.ibm.linux.z.lgdd/lgdd_t_cpu_online.html]

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/sys/devices/system/cpu/cpufreq/ondemand $ cat up_threshold 50

[링크 : https://raspberrypi.stackexchange.com/questions/9034/how-to-change-the-default-governor]