Disable cpu hotplug on Hikey960

Hi,

Can you please let me know how to disable cpu hotplug on Hikey960.
And also to increase cpu performance by applying any tunnables.

Thanks

Hi @Anonymous,

Now we have no any hotplug dynamic mechanism on Hikey960 (such like hotplug governor); the system keeps to run 8 cores simultaneously. So I don’t know clearly what’s your question meaning.

For what it worth, you could use command to hotplug off any specific CPU and hotplug in it again:

echo 0 > /sys/devices/system/cpu/cpuX/online
echo 1 > /sys/devices/system/cpu/cpuX/online

You could adjust the “sustainable_power” to a bigger value so can loose thermal throttling for CPU frequency; if you set “99999999” to sustainable power, this can let thermal framework doesn’t impose limitation on CPU frequency:

echo 99999999 > /sys/class/thermal/thermal_zone0/sustainable_power

You could adjust the “sustainable_power” to a bigger value so can loose thermal throttling for CPU frequency; if you set “99999999” to sustainable power, this can let thermal framework doesn’t impose limitation on CPU frequency:

echo 99999999 > /sys/class/thermal/thermal_zone0/sustainable_power

Having said that the most obvious “tuneable” if you are trying to do
benchmarking of the cores is to fit a very large heat sink and a fan!

IIRC if you get the chip too hot then regardless of what performance
level the kernel asks for the SoC will enter a kind of “limp mode”
to prevent itself from burning up.

Daniel.

Thanks for Daniel’s reminding. I should mention this ahead.