How many CPU cores are usable on Nvidia Drive AGX?

[greivin.fallas]

Please provide the following info:
Hardware Platform: DRIVE AGX Xavier™ Developer Kit
Software Version: DRIVE Software 10
Host Machine Version: native Ubuntu 18.04
SDK Manager Version: 1.0.1.5538

Hi all,

Just a quick question regarding the available CPU cores on Nvidia Drive Xavier.
From official documentation and the Hardware description for the Nvidia Drive AGX, It is mentioned that the Xavier SOCs are 8-core CPUs based on ARM v8 but inspecting with HTOP and Tegrastats, there are only 6 cores displayed.

So, is it possible to enable the 8 cores on the SOCs, Xavier A and Xavier B?

Reference documentation here: https://developer.nvidia.com/drive/drive-agx

Component description:

If we compare a Jetson Xavier AGX, there is a special mode to enable all 8 CPU cores, reference image:

We are interested in an equivalent procedure to enable all 8 CPU cores on the Nvidia Drive AGX if possible.

HTOP output from Xavier A, 6 cores:

If we review the device-tree, we see references to only 6 CPU cores, Is there a limitation to enable 8 CPU cores on Nvidia Drive AGX?

nvidia@tegra-ubuntu ~ $ ls /proc/device-tree/cpus/
‘#address-cells’ cpu@0 cpu@3 cpu_cluster_group_power_states cpu_crossover_thresholds
‘#size-cells’ cpu@1 cpu@4 cpu_cluster_power_states name
cpu-map cpu@2 cpu@5 cpu_core_power_states

Any information on this topic will be really helpful.

Thanks in advance.

[raul.tambre.clevon]

See tegrastats reports only 6 cpu cores. - #3 by SteveNV

If you don’t use NVIDIA’s hypervisor/VM setup and run baremetal you’ll be able to use the full 8 cores. That’s what I do.

[v.toanlm4]

@raul.tambre.clevon:
I’m using a NVIDIA Drive AGX Xavier, when I run “nproc”, the result is only 2; while all 6 cores are online.
Do you know how to change it to 6?
Thanks a lot,
Toan Le

[raul.tambre.clevon]

Might be RoadRunner hogging cores to itself. Try the fix from here.

[v.toanlm4]

There is no RoadRunner in my kit. Trying to find out. Thanks.