Hey,
I can’t enable ‘Max Reflection Bounces’ > 1 in UE 5.5.1 on Linux, because system freezes instantly after changing setting and ~30s later crash is reported. Does anyone have similar issue?
Steps to repro
- Create new Blank project,
- Add Post Process Volume with the following settings:
Infinite Extent (Unbounded) - True
Lumen Global Illumination:
- Ray Lighting Mode - Hit Lighting for Reflections
- Max Reflection Bounces — 2
- Observe system freeze and crash as soon as ‘Max Reflection Bounces’ set to 2.
System
- Arch Linux
- Nvidia driver version: 565.77 (latest)
- GPU: NVIDIA GeForce RTX 2080 with Max-Q Design
Crash logs that are reported
Summary
LoginId:da2c660889ab4b03877c5db4ab6ccf42-000003e8
Assertion failed: bSuccess [File:./Runtime/VulkanRHI/Private/VulkanCommandBuffer.cpp] [Line: 502]
libUnrealEditor-VulkanRHI.so!FVulkanCommandBufferManager::WaitForCmdBuffer(FVulkanCmdBuffer*, float) [/mnt/zfs/ue/UnrealEngine-5.5.1-release/Engine/Source/./Runtime/VulkanRHI/Private/VulkanCommandBuffer.cpp:502]
libUnrealEditor-VulkanRHI.so!FVulkanViewport::WaitForFrameEventCompletion() [/mnt/zfs/ue/UnrealEngine-5.5.1-release/Engine/Source/./Runtime/VulkanRHI/Private/VulkanViewport.cpp:285]
libUnrealEditor-VulkanRHI.so!FVulkanViewport::Present(FVulkanCommandListContext*, FVulkanCmdBuffer*, FVulkanQueue*, FVulkanQueue*, bool) [/mnt/zfs/ue/UnrealEngine-5.5.1-release/Engine/Source/./Runtime/VulkanRHI/Private/VulkanViewport.cpp:1151]
libUnrealEditor-VulkanRHI.so!FVulkanCommandListContext::RHIEndDrawingViewport(FRHIViewport*, bool, bool) [/mnt/zfs/ue/UnrealEngine-5.5.1-release/Engine/Source/./Runtime/VulkanRHI/Private/VulkanRHI.cpp:1236]
libUnrealEditor-RHI.so!FRHICommand<FRHICommandEndDrawingViewport, FRHICommandEndDrawingViewportString2359>::ExecuteAndDestruct(FRHICommandListBase&) [/mnt/zfs/ue/UnrealEngine-5.5.1-release/Engine/Source/Runtime/RHI/Public/RHICommandListCommandExecutes.inl:575]
libUnrealEditor-RHI.so!FRHICommandListBase::Execute() [/mnt/zfs/ue/UnrealEngine-5.5.1-release/Engine/Source/./Runtime/RHI/Private/RHICommandList.cpp:429]
libUnrealEditor-RHI.so!FRHICommandListExecutor::FTranslateState::Translate(FRHICommandListBase*) [/mnt/zfs/ue/UnrealEngine-5.5.1-release/Engine/Source/./Runtime/RHI/Private/RHICommandList.cpp:902]
libUnrealEditor-RHI.so!UE::Core::Private::Function::TFunctionRefCaller<FRHICommandListExecutor::FSubmitState::Dispatch(FRHICommandListBase*)::$_0, void>::Call(void*) [/mnt/zfs/ue/UnrealEngine-5.5.1-release/Engine/Source/./Runtime/RHI/Private/RHICommandList.cpp:871]
libUnrealEditor-RHI.so!FRHICommandListExecutor::FTaskPipe::Execute(FRHICommandListExecutor::FTaskPipe::FTask*, TRefCountPtr<FBaseGraphTask> const&) const [/mnt/zfs/ue/UnrealEngine-5.5.1-release/Engine/Source/Runtime/Core/Public/Templates/Function.h:470]
libUnrealEditor-Core.so!TGraphTask<TFunctionGraphTaskImpl<void (ENamedThreads::Type, TRefCountPtr<FBaseGraphTask> const&), (ESubsequentsMode::Type)0> >::ExecuteTask() [/mnt/zfs/ue/UnrealEngine-5.5.1-release/Engine/Source/Runtime/Core/Public/Templates/Function.h:470]
libUnrealEditor-Core.so!UE::Tasks::Private::FTaskBase::TryExecuteTask() [/mnt/zfs/ue/UnrealEngine-5.5.1-release/Engine/Source/Runtime/Core/Public/Tasks/TaskPrivate.h:504]
libUnrealEditor-Core.so!FNamedTaskThread::ProcessTasksNamedThread(int, bool) [/mnt/zfs/ue/UnrealEngine-5.5.1-release/Engine/Source/Runtime/Core/Public/Async/TaskGraphInterfaces.h:482]
libUnrealEditor-Core.so!FNamedTaskThread::ProcessTasksUntilQuit(int) [/mnt/zfs/ue/UnrealEngine-5.5.1-release/Engine/Source/./Runtime/Core/Private/Async/TaskGraph.cpp:667]
libUnrealEditor-RenderCore.so!FRHIThread::Run() [/mnt/zfs/ue/UnrealEngine-5.5.1-release/Engine/Source/./Runtime/RenderCore/Private/RenderingThread.cpp:269]
libUnrealEditor-Core.so!FRunnableThreadPThread::Run() [/mnt/zfs/ue/UnrealEngine-5.5.1-release/Engine/Source/./Runtime/Core/Private/HAL/PThreadRunnableThread.cpp:25]
libUnrealEditor-Core.so!FRunnableThreadPThread::_ThreadProc(void*) [/mnt/zfs/ue/UnrealEngine-5.5.1-release/Engine/Source/Runtime/Core/Private/HAL/PThreadRunnableThread.h:187]
libc.so.6!UnknownFunction(0x9439c)
libc.so.6!UnknownFunction(0x11949b)
dmesg
[24760.242999] NVRM: Xid (PCI:0000:01:00): 109, pid=9348, name=UnrealEditor, Ch 00000046, errorString CTX SWITCH TIMEOUT, Info 0xbc038
Also found relevant thread, so issue may be with drivers rather than UE itself: Xid109 CTX SWITCH TIMEOUT Driver Crashes In Many Applications - Linux - NVIDIA Developer Forums