[Performance issues] Unstable CPU usage, 19%-41.6%

[zymouse]

Introducing.

ros2_v4l2_camera is a great hardware accelerated camera ros driver. I did the following test.

test environment

• jetpack6.0
• Jetson AGX Orin
• ros2 humble
• branch: galactic
• commit：1029edd3a763b73ac44aad0c5175f1ef88c42d4d
• ros2 run rqt_image_view rqt_image_view
  

Determined in advance:

• It works fine, I can subscribe to the "Camera Images" thread properly!
• Using the same camera: sensing

Problem Description:
The test environment is the same as the test method

• Starting ros2 run v4l2_camera v4l2_camera_node
• Using ros2 run rqt_image_view rqt_image_view

Test Description:
CPU usage stabilized at around 20% in the morning test

In the afternoon, the CPU usage stabilized at around 37%.

The CPU usage is not the same in both tests, which I don't think is a normal phenomenon

@knzo25

[knzo25]

@manato
I think this falls under your expertise rather than mine 😅

[manato]

@knzo25
Thanks for connecting.

@zymouse
The CPU usage possibly gets higher just after trying to establish ROS connection, and then gets stable at low usage after a while. I would appreciate it if you check the usage after a while to see the usage gets stable. Besides, I guess the reported value might vary depending on the load sample frequency. When you observe a similar high CPU usage, I would also appreciate if you could restart load measurements a few times just in case. Thanks.