Bug [OpenXR] Player/Editor Memory Leaking with Oculus Runtime

There seems to be a memory leak whenever I use the OpenXR plugin together with the Oculus OpenXR runtime which has been causing a fair share of issues. Whenever OpenXR transitions from a focused to idle state (i.e. taking a Rift S HMD on and then off your head), it looks like CanvasBatchRenderers will start to gradually increase how much memory it is spending. The speed of this leak also seems to be proportional to the amount of canvases or UI elements there are in the active scene.

If I take the controller sample scene from the OpenXR plugin, add a camera space canvas which I then add a few hundred child buttons under with their own canvases, I end up with the following after a few seconds:

If I let it run for an extra minute or two it starts to look like this:


There does not seem to be a hard cap for how much memory CanvasBatchRenderers can eat up as I've managed to let it run for long enough to eat up ~14-15GB worth of RAM and cause major system slowdowns.

Has anyone else experienced the same issue or found potential ways to work around it? (outside of disabling XR as soon as OpenXR goes to idle state. Doing that could end up being pretty tedious if you quickly take your headset off/on to check something on your desktop). I've submitted a bug report for the issue (#1344762), so hopefully it ends up being fixable soon enough.

 

Hey. I actually reached out on the Oculus dev forums and Unity replied to me there about this:

"We've seen reports of a memory leak on headset idle when using UI Canvases. We're working on getting a fix released."

He said it required a fix in core Unity, not OpenXR. A workaround was supposedly disabling canvases when OpenXR reports a state change to IDLE, but that will be more trouble than its worth for me so I'm waiting on the fix.

https://docs.unity3d.com/Packages/c...SessionStateChange_System_Int32_System_Int32_

 

Noticed memory leaks over past year even in Oculus legacy and oculus plugin.

 

I am also having memory leak issues too, but I am using a Vive with the OpenXR plugin going through SteamVR/OpenVR. If I start and stop the play tests enough times, Unity will first warn me that it cannot create a render texture. If I do not respond fast enough to close Unity after that warning, it can crash my computer. I also noticed in task manager that the memory starts increasing every time I play test after a while as well.

 

Now for some reason I cannot get it to crash after play testing my game I was working on or on a blank empty project. Though restarting the computer before didn't fix it and I did not update anything. But I did see some memory increase on the profiler and task manager. All I did was create a empty 3D Project and installed the OpenXR plugin 1.2.3. Enabled it and fixed what it wanted to be fixed. Added controller profiles and then I just started to hit play button over and over again.
Here is a pic before I started to start and stop the play tests many times:

Here is after I repeatedly started and stopped the test plays:

I don't know if this helps or not. Sorry I couldn't gather any other data and I cannot explain why it is now "working", but I am unsure.

 

One question, can turning off Virtual Memory or Paging Memory from the system settings cause this issue that I am having? Because I was having other apps crash due to running out of memory, I just remembered that I had this feature turned off because I was concerned about my disks but I forgot to set it back on. Turning the feature back to on through my system settings made the others apps work all of a sudden with no problems. So I am assuming that this should fix it? I am sorry for all of the confusion.

 

Unity seems to be working now at the moment. I even let the VR idling for a while and came back as another test and no problems so far for me. I did multiple play tests with no issues coming up as well. Also VR seems to be a bit faster now too I think. So I guess that setting Virtual Memory or Memory Paging to off for my Windows seems to break some things. I am sorry for the inconvenience because of a system setting.

 

Hi,

It looks like this issue was marked resolved, but the fixes do not include Unity 2020, only 2021? Is there a specific version of 2020 this was fixed in?

https://issuetracker.unity3d.com/is...oconsoleimplementation-when-exiting-play-mode

 

Awesome. Thanks!