Force only low power cores on TX1

Robotics & Edge Computing Jetson & Embedded Systems Jetson TX1
1

I’m running some timings and power measurements for simulation code on the TX1. Since the board has the low power companion cores I wanted to see how those differed from the main cores and wanted to just run the LP cluster. I want to force just the LP cores but I haven’t figured out how.

I tried modifying the instructions from here:
[url]https://devtalk.nvidia.com/default/topic/894945/jetson-tx1/jetson-tx1/7[/url]

and here:
[url]http://elinux.org/Jetson_TK1[/url]

to force just the low power cores on the TX1. It seems that with the new L4T R24.1 the cluster options have either been moved somewhere else or removed all together.

Is it still possible to force just the low power cores to run?

2

from what i have read they are not software linked.
https://devtalk.nvidia.com/default/topic/904289/jetson-tx1/does-anyone-get-8-cpus-listed-/

3

The A53’s aren’t used because of a libc incompatibility with the A57’s (out-of-order execution) and aren’t lower power anyhow. You can use sysfs to control force the A57 cores online or offline however, using these file entries:

for i in 0 1 2 3 ; do
	echo 1 > /sys/devices/system/cpu/cpu${i}/online
done

See this script for example: https://github.com/dusty-nv/jetson-scripts/blob/master/jetson_max_l4t.sh

Alternatively there are useful commands listed here: http://elinux.org/Jetson/Performance

4

Thanks for the response. I wanted to use the A53’s to test execution time and power consumption vs the A57’s.

The info helps me out quite a lot.