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bashsshbenchmarkingmulticore

Disable all but one core via bash command

Is there a way to switch off one of the cores of a dual core machine via a bash command? I am trying to compare the performance of different machines and I want to use only one core in each of the machines. Is there a way to do that? (Note that I am doing this via SSH, so please tell me the options which will work via SSH. I do have root privileges though.)

Solution

  • Here you go:

    root# echo 0 > /sys/devices/system/cpu/cpu1/online
root# dmesg | tail | grep CPU
[23164.810371] CPU 1 is now offline

    Redirection is done by the shell so if you need to use sudo, run it like this

    $ sudo sh -c 'echo 0 >/sys/devices/system/cpu/cpu1/online'

    If you're on a tilera ;)

    root# for i in $(seq 1 99); do echo 0 >/sys/devices/system/cpu/cpu$i/online; done