search

christianrauch / camera_ros

ROS 2 node for libcamera supported cameras (V4L2, Raspberry Pi Camera Modules)
https://libcamera.org
MIT License
68 stars 30 forks source link

Memory leak? #5

Closed JohK closed 2 years ago

JohK commented 2 years ago

Just noticed that the VIRT value in top was increasing monotonically for camera_node and it's chomping away on my free memory (slowly). A pointer that's not freed?

I attached you pmap output, is it the list of dmabuf that is growing indefinately?

pmap.CameraNode.txt

christianrauch commented 2 years ago

I attached you pmap output, is it the list of dmabuf that is growing indefinately?

Well, you have to monitor this over time :-)

I've never used pmap to monitor memory consumption. I usually just look at htop and friends to see if a process leaks memory, and ASan and valgrind to debug this.

Just noticed that the VIRT value in top was increasing monotonically for camera_node and it's chomping away on my free memory (slowly). A pointer that's not freed?

I've seen memory leaks around the publishing of images before. When I removed the image message creation, conversion and publishing, the leaks go away. But this of course defies the purpose of the ROS node. I was never able to properly pinpoint the issue.

It may also depend on the camera. I have an integrated RGB and IR camera (a.k.a. "Windows Hello"). Using the "640x480-MJPEG" stream for the IR camera causes the leak and using "1280x720-MJPEG" for the RGB camera does not leak memory. It may be as well that something else in the stack leaks.

christianrauch commented 2 years ago

@JohK You were right about dmabuf. I forgot to call munmap on the mmap-ed buffers returned by libcamera. This is fixed now on the newest main.

You can compare this with something like pmap $(pidof camera_node) | grep dmabuf | wc -l, which will show the number of dmabuf entries in the process map. This should be 0 now. Before it was growing indefinitely. Also the total amount of memory reported by pmap should now be more or less constant.