x

Search in
Sort by:

Question Status:

Search help

  • Simple searches use one or more words. Separate the words with spaces (cat dog) to search cat,dog or both. Separate the words with plus signs (cat +dog) to search for items that may contain cat but must contain dog.
  • You can further refine your search on the search results page, where you can search by keywords, author, topic. These can be combined with each other. Examples
    • cat dog --matches anything with cat,dog or both
    • cat +dog --searches for cat +dog where dog is a mandatory term
    • cat -dog -- searches for cat excluding any result containing dog
    • [cats] —will restrict your search to results with topic named "cats"
    • [cats] [dogs] —will restrict your search to results with both topics, "cats", and "dogs"

iOS GPU hang/crash on devices with A7 and A8 chipsets

Hi,

We're seeing a crash the second time we run our app. This is the error in the log:

 May 30 10:34:06 Ryan-Lancasters-iPhone Submerged[5582] <Warning>: Fatal error: [File:/Users/UG_iMac/Perforce/Submerged_Moblie/Engine/Source/Runtime/Apple/MetalRHI/Private/MetalCommandList.cpp] [Line: 51] 
     Command Buffer Frame2 Failure! Error Domain: MTLCommandBufferErrorDomain Code: 2 Description Caused GPU Hang Error (IOAF code 3) Unknown Unknown
 

Googling "IOAF code 3" I found this page: https://forums.developer.apple.com/thread/24702

It basically says that the hang/crash is caused by the threadgroup_barrier function not being encountered by all threads in the thread group.

I found the code in the engine that puts this function into the Metal shader and there was this comment above the code (MetalBackend.cpp line 1901):

 //@todo-rco: Fix this properly

Any chance this has been "fixed properly" yet?

Log with GPU state

Regards,

Ryan.

Product Version: UE 4.11
Tags:
crashlog.txt (7.8 kB)
more ▼

asked May 30 '16 at 12:55 AM in Bug Reports

avatar image

LuaChunk
95 8 10 33

(comments are locked)
10|2000 characters needed characters left
Viewable by all users

1 answer: sort voted first

LuaChunk,

This issue has already been reported as: UE-30847. It's a priority 2, major bug and it's on our to do list. Please feel free to ask for updates as various versions of the engine come out.

Thanks!

more ▼

answered Jun 03 '16 at 07:34 PM

avatar image LuaChunk Jun 07 '16 at 01:42 AM

If anyone else has this issue here's our workaround: The bug was caused by us loading a small empty map, checking if the player had a save game file and changing the way we loaded our main map based on the save data. We were triggering the level load from the Begin Play event in the empty level's blueprint. To fix the crash we changed it to run the code on the first Tick of the empty level blueprint instead of the Begin Play.

(comments are locked)
10|2000 characters needed characters left
Viewable by all users
Your answer
toggle preview:

Up to 5 attachments (including images) can be used with a maximum of 5.2 MB each and 5.2 MB total.

Follow this question

Once you sign in you will be able to subscribe for any updates here

Answers to this question