LuxMark 3.1 segfaults on Skylake IGP

[aufkrawall]

When I try to run LuxMark 3.1 on the i7 6700k IGP, it crashes:

./luxmark
free(): invalid pointer
./luxmark: line 12: 59158 Aborted (core dumped) ./luxmark.bin "$@"

This is on Arch with
linux 5.3.4
intel-compute-runtime 19.37.14191
intel-graphics-compiler 1:1.0.11

clinfo.log

IGP is used only for CL, display output and desktop rendering runs via dGPU (Polaris).
On Polaris, LuxMark works with Clover, OCL-Orca- OCL-PAL and OCL-ROCm.

[JacekDanecki]

Can you provide stack trace from gdb?

[aufkrawall]

I'm on Arch, I'd have to recompile with debug symbols. Is it enough when intel-compute-runtime includes them?

[jdanecki]

Let's start with luxmark itself. Can you verify whether there was gpu hang in dmesg?

[jdanecki]

I've reproduced this issue with Luxmark 3.1 with:

$ pacman -Q intel-compute-runtime intel-graphics-compiler intel-opencl-clang 
intel-compute-runtime 19.39.14278-1
intel-graphics-compiler 1:1.0.2652-1
intel-opencl-clang 9.0.0-1

under Arch

[New Thread 0x7fffacff9700 (LWP 20472)]
free(): invalid pointer

Thread 3 "luxmark.bin" received signal SIGABRT, Aborted.
[Switching to Thread 0x7ffff51d2700 (LWP 20391)]
0x00007ffff718af25 in raise () from /usr/lib/libc.so.6
(gdb) where
#0  0x00007ffff718af25 in raise () from /usr/lib/libc.so.6
#1  0x00007ffff7174897 in abort () from /usr/lib/libc.so.6
#2  0x00007ffff71ce258 in __libc_message () from /usr/lib/libc.so.6
#3  0x00007ffff71d577a in malloc_printerr () from /usr/lib/libc.so.6
#4  0x00007ffff71d714c in _int_free () from /usr/lib/libc.so.6
#5  0x00000000015474af in std::locale::_Impl::~_Impl() ()
#6  0x000000000154768d in std::locale::~locale() ()
#7  0x00007ffff70992c4 in std::basic_streambuf<char, std::char_traits<char> >::~basic_streambuf (this=0x7ffff51cf638, __in_chrg=<optimized out>) at /build/gcc/src/gcc-build/x86_64-pc-linux-gnu/libstdc++-v3/include/streambuf:204
#8  std::__cxx11::basic_stringbuf<char, std::char_traits<char>, std::allocator<char> >::~basic_stringbuf (this=0x7ffff51cf638, __in_chrg=<optimized out>) at /build/gcc/src/gcc-build/x86_64-pc-linux-gnu/libstdc++-v3/include/sstream:65
#9  std::__cxx11::basic_stringstream<char, std::char_traits<char>, std::allocator<char> >::~basic_stringstream (this=0x7ffff51cf620, __in_chrg=<optimized out>, __vtt_parm=<optimized out>) at /build/gcc/src/gcc-build/x86_64-pc-linux-gnu/libstdc++-v3/inclu
de/sstream:784
#10 0x00007fffec680071 in ?? () from /usr/lib/libopencl-clang.so.9
#11 0x0000000000000070 in ?? ()
#12 0x00007ffff51cf610 in ?? ()
#13 0x00007fffebb38560 in ?? ()
#14 0x00007fffe96233e8 in ?? ()
#15 0x00007ffff51cf5b0 in ?? ()
#16 0x00007ffff51cf6a0 in ?? ()
#17 0x00007ffff51cf670 in ?? ()
#18 0x0000000000000012 in ?? ()
#19 0x00007fffebe97488 in ?? ()
#20 0x0000000000000003 in ?? ()
#21 0x0000000000000000 in ?? ()

The same luxmark binaries together with Neo

dpkg -l intel-opencl intel-igc-core intel-igc-opencl | grep ^ii
ii  intel-igc-core   1.0.2597     amd64        Intel(R) Graphics Compiler for OpenCL(TM)
ii  intel-igc-opencl 1.0.2597     amd64        Intel(R) Graphics Compiler for OpenCL(TM)
ii  intel-opencl     19.40.14409  amd64        Intel OpenCL GPU driver

works fine under Ubuntu 18.04.3 LTS. Tested with kernel: 5.3.1-x86_64

@dbermond Have you observed issues with intel-opencl-clang under Arch in other apps?

[dbermond]

@jdanecki Nothing that I can observe or be aware of.

What we are experiencing is a build issue with neo 19.40, apparently with gen12 related code.

[JacekDanecki]

@dbermond Can you provide more details about build problems, or create new issue here? Is it a similar issue like here.
If so, this is known issue on IGC side, and fix is in progress. When you get older IGC, the same as in Neo release 19.40, plus fix for gcc 9 compilation intel/intel-graphics-compiler@028414b, you will be able to compile Neo correctly.
With this newer IGC commit Neo compiles correctly.

[dbermond]

@JacekDanecki That's exactly this issue. Glad to see that a fix is under way.

[aufkrawall]

Still crashes with
intel-compute-runtime 19.40.14409-1
intel-graphics-compiler 1:1.0.2714-1

Stack trace (no idea how helpful it is without debug symbols):
https://drive.google.com/open?id=1ZaPDnmG4_vRN-4rZnI8agYzJmzhrYylp

[JacekDanecki]

@aufkrawall As the issue is observed in intel-opecl-clang library I've compiled:

• intel/opencl-clang@6f8c329
• KhronosGroup/SPIRV-LLVM-Translator@beaa885
  using versions we use in Neo releases (older than in Arch).
  With such compiled libraries luxmark works correctly.

@dbermond Is it possible to downgrade both packages in Arch, so they work correctly with Neo? Actually only spirv-llvm-translator downgrade is requried, and opencl-clang rebuild.

[dbermond]

@JacekDanecki I heavily appreciate your effort in helping to solve this issue in Arch Linux (and I'm sure you know it), but as a general rule we do not downgrade repository packages in such situation. We only downgrade when a package is utterly broken. If there is a patch that we can use, then I would gladly apply it.

Besides, even if downgrading would be an option, I would like to mention that the OP reported this issue with neo 19.37 and igc 1:1.0.11 at the time of his writing. These were already based on the previous versions of intel-opencl-clang (8.0.1) and spirv-llvm-translator (8.0.1.2).

[JacekDanecki]

Neo release 19.38.14237 is the latest release based on llvm/clang 8 on IGC side.
Since intel/intel-graphics-compiler@7117adb IGC switched to newer intel/opencl-clang@v9.0.0 and KhronosGroup/SPIRV-LLVM-Translator@v9.0.0-1. Unfortunately these versions doesn't work in luxmark and debug is in progress.

[JacekDanecki]

When I removed directory /tmp/kernel_cache/LUXCORE_1.5, all scenes work correctly with IGC, opencl-clang, spirv-llvm-translator I mentioned earlier. I've checked it with the latest Neo bfc98631

[JacekDanecki]

New Neo release 19.43.14583 contains intel/intel-graphics-compiler@igc-1.0.2714.1 compiled with intel/opencl-clang@v9.0.0 and KhronosGroup/SPIRV-LLVM-Translator@v9.0.0-1. These binaries works with Luxmark. I've recompiled Neo and IGC components using these versions and Luxmark works under Arch.

[dbermond]

@JacekDanecki Thanks for working on this.