For some benchmarks it can be important to have a system operating on just a specific number of CPU cores. To find out how many you have, just count them by:
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1 |
$ ls -l /sys/devices/system/cpu/ |
Switching a core off is just as easy as
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1 |
echo 0 > /sys/devices/system/cpu/cpu7/online |
which would switch off core 7.
For simplification, i got a shell script for activating/deactivating the cores 2 to 7 on the console (file is called “multiCoreSwitch.sh”:
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1 2 3 4 5 |
#!/bin/bash for cpu in $(seq 2 7) do echo $1 > /sys/devices/system/cpu/cpu$cpu/online done |
Which then can be called by:
Switch on:
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1 |
sudo ./multiCoreSwitch.sh 1 |
Switch off:
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1 |
sudo ./multiCoreSwitch.sh 0 |
For checking whether the cores are running or not, run “top” and enter 1, for toggling the cpu view.