Bug 97122

Created attachment 125387 [details]
dmesg for uniform_iterations#conditional_continue_fragment FAIL

Created attachment 125388 [details]
dmesg for uniform_iterations#double_continue_vertex FAIL

Created attachment 125389 [details]
dmesg for uniform_iterations#double_continue_fragment FAIL

Hi Mauro, thanks for the report - sounds like a control flow lowering bug.

Note that the 'nosb' option will have no effect, it applies to r600 only.

Which version of LLVM are you using? glxinfo shows this. Does the lockup happen with LLVM trunk?

Hi,

llvm version used in android marshmallow-x86 is 3.7.0 (preceding the R600 to AMDGPU target renaming).
On android my options are currently limited to backporting latest patches on top llvm 3.7.0 or trying upgrade to latest llvm 3.7.x doing some AMDGPU target porting of android makefiles.

>'nosb' option will have no effect, it applies to r600 only

Are there other options that could help to workaround the issue
or for debugging purposes?

I'll check if some control flow lowering bug was reported,
in order to apply the relevant changes, do you know

In order to try latest llvm, I will move to linux test run,
by using chadversary fork and report about GLES2 results

Mauro

the missing part of a sentence:

> do you know

if similar GPU lockup bugs may be related and how?

Mauro

I'm sorry, but LLVM 3.7 is extremely old. I'd say you're mostly out of luck.

There have been huge changes to how control flow lowering works, and I'd say trying to cherry-pick individual fixes is basically a hopeless endeavour.

I have verified that the tests pass on current Mesa + LLVM master.

I would seriously recommend that you somehow upgrade the version of LLVM you use with the driver.

Hi Nicolai,

thanks a lot for your commitment and help.

Now I also learned how to run deqp on linux

I confirm that with the llvm 3.8.1 and later I see no GPU lockups.

Being oibaf ppa not affected, the resolution happened between 3.8.0 and 3.8.1
and has to be related to SI lowering, that's a lot of useful info for my problem.

Cheers!
Mauro


Test Sessions:
--------------

cmake . -DDEQP_TARGET=x11_egl
make
cd ./modules/gles2
./deqp-gles2 -n dEQP-GLES2.functional.shaders.loops.*


Test Session 1: padoka ppa (mesa 12.1 and llvm 4.0.0)
---------------------------------------------------

utente@utente-desktop:~$ glxinfo | grep Mesa
client glx vendor string: Mesa Project and SGI
OpenGL core profile version string: 4.2 (Core Profile) Mesa 12.1.0-devel - padoka PPA
OpenGL version string: 3.0 Mesa 12.1.0-devel - padoka PPA
OpenGL ES profile version string: OpenGL ES 3.0 Mesa 12.1.0-devel - padoka PPA

utente@utente-desktop:~$ glxinfo | grep LLVM
    Device: AMD TAHITI (DRM 2.43.0 / 4.4.0-31-generic, LLVM 4.0.0) (0x679a)
OpenGL renderer string: Gallium 0.4 on AMD TAHITI (DRM 2.43.0 / 4.4.0-31-generic, LLVM 4.0.0)


Result: dEQP-GLES2.functional.shaders.loops.* 100% ok and no GPU lockups

DONE!

Test run totals:
  Passed:        624/624 (100.0%)
  Failed:        0/624 (0.0%)
  Not supported: 0/624 (0.0%)
  Warnings:      0/624 (0.0%)


Test Session 2: oibaf ppa (mesa 12.1 and llvm 3.8.1)
--------------------------------------------------

utente@utente-desktop:~$ glxinfo | grep Mesa
client glx vendor string: Mesa Project and SGI
OpenGL core profile version string: 4.1 (Core Profile) Mesa 12.1.0-devel
OpenGL version string: 3.0 Mesa 12.1.0-devel
OpenGL ES profile version string: OpenGL ES 3.0 Mesa 12.1.0-devel
utente@utente-desktop:~$ glxinfo | grep LLVM
    Device: AMD TAHITI (DRM 2.43.0 / 4.4.0-31-generic, LLVM 3.8.1) (0x679a)
OpenGL renderer string: Gallium 0.4 on AMD TAHITI (DRM 2.43.0 / 4.4.0-31-generic, LLVM 3.8.1)

Result: dEQP-GLES2.functional.shaders.loops.* are 100% ok and no GPU lockups

DONE!

Test run totals:
  Passed:        624/624 (100.0%)
  Failed:        0/624 (0.0%)
  Not supported: 0/624 (0.0%)
  Warnings:      0/624 (0.0%)


Test Session 3: default Ubuntu 16.04 (mesa 11.2 and llvm 3.8.0)
-------------------------------------------------------------

utente@utente-desktop:~$ glxinfo | grep Mesa
client glx vendor string: Mesa Project and SGI
OpenGL core profile version string: 4.1 (Core Profile) Mesa 11.2.0
OpenGL version string: 3.0 Mesa 11.2.0
OpenGL ES profile version string: OpenGL ES 3.0 Mesa 11.2.0

utente@utente-desktop:~$ glxinfo | grep LLVM
    Device: AMD TAHITI (DRM 2.43.0, LLVM 3.8.0) (0x679a)
OpenGL renderer string: Gallium 0.4 on AMD TAHITI (DRM 2.43.0, LLVM 3.8.0)


Result: Full screen artifacts and GPU lockup, but clearly llvm version related