Bug 103126 - glthread doesn't offload anything in Witcher 2
Summary: glthread doesn't offload anything in Witcher 2
Status: RESOLVED INVALID
Alias: None
Product: Mesa
Classification: Unclassified
Component: Mesa core (show other bugs)
Version: 17.2
Hardware: Other All
: medium normal
Assignee: mesa-dev
QA Contact: mesa-dev
URL:
Whiteboard:
Keywords:
Depends on:
Blocks:
 
Reported: 2017-10-06 16:49 UTC by Alexander Tsoy
Modified: 2018-05-11 00:50 UTC (History)
1 user (show)

See Also:
i915 platform:
i915 features:

Attachments
witcher2_glthread.png (4.67 MB, image/png)
2017-10-06 16:49 UTC, Alexander Tsoy 		Details
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Description Alexander Tsoy 2017-10-06 16:49:06 UTC 
Created attachment 134710 [details]
witcher2_glthread.png

Even though there were reports that glthread improves performance in Witcher 2, and it was enabled via drirc in recent mesa versions, it never worked for me. "API-thread-offloaded-slots" always stays at zero, see attached screenshot.

In other games like Civilization 5 glthread works on my system as expected.


My current package versions:

linux-4.13.5
mesa-17.2.2
llvm-5.0.0
libdrm-2.4.82
xf86-video-amdgpu-1.4.0
Comment 1 Alexander Tsoy 2017-10-06 16:50:14 UTC 
My GPU:
01:00.0 VGA compatible controller [0300]: Advanced Micro Devices, Inc. [AMD/ATI] Tonga PRO [Radeon R9 285/380] [1002:6939] (rev f1) (prog-if 00 [VGA controller])
Comment 2 Alexander Tsoy 2017-12-05 17:39:01 UTC 
I had the same problem with other eON ports: Spec Ops: The Line and Overlord at least. It's turned out that it's due to disabled assembly in my 32-bit mesa build (--disable-asm). Not sure if it worth fixing this. Leaving the bug open for developers to decide.
Comment 3 Timothy Arceri 2018-03-06 05:24:17 UTC 
I believe the dispatch code uses asm, disabling it probably falls back to a dispatch path that doesn't contain glthread. Either that or something else glthread related relies on asm being enabled. Either way this doesn't seem like a bug. Closing.
Comment 4 Marek Olšák 2018-05-10 23:59:04 UTC 
I don't think this has anything to do with 32 bits. There are 32-bit apps where glthread works. Witcher 2 is an app where glthread gets disabled.
Comment 5 Timothy Arceri 2018-05-11 00:50:40 UTC 
(In reply to Marek Olšák from comment #4)
> I don't think this has anything to do with 32 bits. There are 32-bit apps
> where glthread works. Witcher 2 is an app where glthread gets disabled.

Yeah it's not a 32bit issue apparently glthread doesn't work with --disable-asm

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