Memory leak in UE 5.6 in Linux

Development Programming & Scripting
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In our Linux based cloud rendering application (using Vulkan) we have seen in our new UE 5.6 based application it is leaking approximately 5GB over 16 hours which then causes the application to crash.

While this might not be a problem for a regular game, for a cloud based rendering service it needs to run much longer than this. Our previous UE 5.4 based application didn’t have this issue.

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There seem to be some other very similar issues with/without reproduction projects such as [this [Content removed] and [this [Content removed]

As per this link and this link we ran insights to look for memory leaks. It seems to identify some leaks which seem to correlate between the points in the insights capture where it progressively steps up. We can’t identify precisely what these leaked bits of memory are (or where they come from). We have 0 code in this blank project so its somewhere in the engine. We likely can’t get more specifics due to this issue which seems to relate.

Please find the insights capture attached.

Thanks a lot for your help!

Jason

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Steps to Reproduce
Launch blank scene project and watch memory climbing.

Can also perform insights capture (we have attached one) and use memory leak tool to try and identify the leak (its not easy in Linux as it seems there are issues in the insights tool with symbol loading)

3

Hi Jason,

5.6 did have a leak in Vulkan Split Barriers which may account for this slow but steady leak. You can try adding r.Vulkan.AllowSplitBarriers=0. The leak itself was fixed as CL 47756075 (only the changes in VulkanBarriers.cpp are necessary). Should the leak persist with either the CVar workaround or the fix, please let us know as there would another undetected leak lingering in the Vulkan RHI potentially.

Best regards.

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Thanks Jason, we’ll be on the lookout for a follow up once you have had a chance to try these suggestions.

Best regards.

5

Great news, thanks for letting us know Jason.

Best regards.

6

Thanks [Content removed]

We’ll look into that and let you know how we get on

7

Hey [Content removed]

Good news, applying the changes in CL 47756075 to 5.6.1 fixed the leak!

I have selected your previous answer as the best.

Thanks a lot for your help.

Regards,

Jason