Possible to change min frequency of only CPU0 or only CPU0 and CPU1 leaving other clusters with different min?

Autonomous Machines Jetson & Embedded Systems Jetson AGX Xavier
1

We have an application that receives a lot of data over Ethernet and this tends to load up CPU 0. We have noticed that we get less errors if we run Jetson Clocks. Ideally we just want to run CPU 0 at full clock rate (as this seems to be the CPU that handles interrupts and ethernet packets), but let the others dynamically change to keep power consumption down.

We have tried create a new POWER_MODEL in /etc/nvpmodel.conf but if we set something like:
CPU_DENVER_0 MIN_FREQ 1190400
CPU_DENVER_1 MIN_FREQ 576000
Then all the cores seem to get the same minimum.

Similarly if we write directly to /sys/devices/system/cpu/cpu0/cpufreq/scaling_min_freq then all the CPU’s seem to get this new minimum.

Is it possible to control the minimum CPU frequency for selected CPU’s on the Xavier?

Thanks for you help

3

hello jon.richardsm6bq8,

please check Xavier Series Module Data Sheet,
the configuration you did is Denver cores, instead of Carmel CPUs.

4

Hi Jerry,
I think that’s just a hang over in the /etc/nvpmodel.conf from earlier Jetsons. The bash variable the script uses is still called CPU_DENVER. I’m on Jetpack 4.2.1. For example:

< POWER_MODEL ID=4 NAME=MODE_30W_6CORE >
CPU_ONLINE CORE_0 1
CPU_ONLINE CORE_1 1
CPU_ONLINE CORE_2 1
CPU_ONLINE CORE_3 1
CPU_ONLINE CORE_4 1
CPU_ONLINE CORE_5 1
CPU_ONLINE CORE_6 0
CPU_ONLINE CORE_7 0
TPC_POWER_GATING TPC_PG_MASK 0
GPU_POWER_CONTROL_ENABLE GPU_PWR_CNTL_EN on

CPU_DENVER_0 MIN_FREQ 1200000
CPU_DENVER_0 MAX_FREQ 1450000
CPU_DENVER_1 MIN_FREQ 1200000
CPU_DENVER_1 MAX_FREQ 1450000
CPU DENVER_2 MIN_FREQ 1200000
CPU_DENVER_2 MAX_FREQ 1450000
GPU MIN_FREQ 318750000
GPU MAX_FREQ 900000000
GPU_POWER_CONTROL_DISABLE GPU_PWR_CNTL_DIS auto
EMC MAX_FREQ 1600000000
DLA_CORE MAX_FREQ 1050000000
DLA_FALCON MAX_FREQ 630000000
PVA_VPS MAX_FREQ 760000000
PVA_CORE MAX_FREQ 532000000
CVNAS MAX_FREQ 1011200000
5

hello jon.richardsm6bq8,

it’s some confusing that Xavier don’t have Denver cores, but configure file still naming CPU-0,2,4,6 as Denver-0,1,2,3.
back to your original question, it’s not able to configure the minimum CPU frequency for the selected CPU core.