[llvm-dev] Debug info for CUDA code

Wed Jan 15 11:29:55 PST 2020

On Wed, Jan 15, 2020 at 11:20 AM Alexey Bataev via llvm-dev <
llvm-dev at lists.llvm.org> wrote:

> Hi Char, not sure if clang supports 10.2. You can ry to use trunk instead
> of release and check it yourself. Most probably clang 10 will support cuda
> 10. Also, you can use cuda 9 safely, just replace ptxas in the installation
> dir with the newest ptxas from cuda 10.2
>
Clang does not have support for CUDA 10.2 yet. I'll try to get the patch
for basic support out in upcoming weeks,
unless someone beats me to it.

If all you need is to work around a bug in ptxas, replacing it is a
reasonably
safe approach (modulo things that may have been changed/deprecated in the
new version).

--Artem

> -------------
> Best regards,
> Alexey Bataev
>
> 15.01.2020 9:17 AM, treinz пишет:
>
> Hi Alexey,
>
> Almost a year has passed and Nvidia finally fixes the ptxas issue in CUDA
> 10.2 according to:
> https://docs.nvidia.com/cuda/cuda-toolkit-release-notes/index.html#cuda-compiler-resolved-issues
> However, I can not yet use it with llvm 9.0.0 release because CUDA 10.2 is
> not supported yet. Is there other branches of the llvm repo that supports
> CUDA 10.2 now? Or do I need to wait for llvm 10 releaase.
>
> Thanks,
> Char
>
> At 2019-02-28 02:09:54, "Alexey Bataev" <a.bataev at outlook.com>
> <a.bataev at outlook.com> wrote:
>
> Hi Char, it looks like they have some kind of buffer overflow bug in their
> ptxas tool.
>
> -------------
> Best regards,
> Alexey Bataev
>
> 27.02.2019 13:08, treinz пишет:
>
> Hi Alexey,
>
> I submitted the bug report to nvidia. While they are working on it, can
> you share some insight in what could potentially cause this? I just want to
> get a sense if such a bug require significant amount of work to fix, which
> can help me make some decision moving forward with my project.
>
> Thanks,
> Char
>
> At 2019-02-27 03:19:02, "Alexey Bataev" <a.bataev at outlook.com>
> <a.bataev at outlook.com> wrote:
>
> Hi Char, yes, this line causes the crash. You don't need .cu files (I
> don't know what files are you talking about, clang does not generate .cu
> files). You need just this .s file to reproduce the error and nothing else.
>
> -------------
> Best regards,
> Alexey Bataev
>
> 26.02.2019 13:06, treinz пишет:
>
> Hi Alexey,
>
> Just want to make sure I understand what you said because I'm not familiar
> with the llvm pipeline, it's this line:
>
> /net/gs/vol3/software/modules-sw/cuda/10.0/Linux/RHEL6/x86_64/bin/ptxas"
> -m64 -g --dont-merge-basicblocks --return-at-end -v --gpu-name sm_75
> --output-file /tmp/60663577.1.login.q/testparticles-4fd988.o
> /tmp/60663577.1.login.q/testparticles-1d20c4.s
>
> that segfaults, where the testparticles-1d20c4.s is generated by the
> command:
>
> /home/aznb/.linuxbrew/Cellar/llvm/HEAD-48aefa8/bin/clang-9" -cc1 -triple
> nvptx64-nvidia-cuda -aux-triple x86_64-unknown-linux-gnu -S -disable-free
> -disable-llvm-verifier -discard-value-names -main-file-name
> testparticles.cpp -mrelocation-model static -mthread-model posix
> -mdisable-fp-elim -no-integrated-as -fuse-init-array -fcuda-is-device
> -mlink-builtin-bitcode
> /net/gs/vol3/software/modules-sw/cuda/10.0/Linux/RHEL6/x86_64/nvvm/libdevice/libdevice.10.bc
> -target-feature +ptx61 -target-cpu sm_75 -dwarf-column-info
> -debug-info-kind=limited -dwarf-version=2 -debugger-tuning=gdb -v
> -resource-dir
> /home/aznb/.linuxbrew/Cellar/llvm/HEAD-48aefa8/lib/clang/9.0.0
> -internal-isystem
> /home/aznb/.linuxbrew/Cellar/llvm/HEAD-48aefa8/lib/clang/9.0.0/include/cuda_wrappers
> -internal-isystem
> /net/gs/vol3/software/modules-sw/cuda/10.0/Linux/RHEL6/x86_64/include
> -include __clang_cuda_runtime_wrapper.h -isystem
> /home/aznb/.linuxbrew/Cellar/boost/1.68.0_clang/include/boost-1_68 -I
> /home/aznb/mycodes/scbmc -I
> /home/aznb/mycodes/scbmc/build_cuda_clang_debug/_deps/kokkos-src/core/src
> -I
> /home/aznb/mycodes/scbmc/build_cuda_clang_debug/_deps/kokkos-src/containers/src
> -I
> /home/aznb/mycodes/scbmc/build_cuda_clang_debug/_deps/kokkos-src/algorithms/src
> -I /home/aznb/mycodes/scbmc/build_cuda_clang_debug/_deps/kokkos-build -I
> /home/aznb/mycodes/scbmc/../thrust -I
> /net/gs/vol3/software/modules-sw/cuda/10.0/Linux/RHEL6/x86_64/include -I
> /home/aznb/mycodes/scbmc/build_cuda_clang_debug/_deps/kokkosutils-src -I
> /home/aznb/mycodes/scbmc/build_cuda_clang_debug/_deps/alias-src -I
> /home/aznb/mycodes/scbmc/build_cuda_clang_debug/_deps/ziggurat-src -I
> /home/aznb/mycodes/scbmc/build_cuda_clang_debug/_deps/distribution-src -I
> /home/aznb/mycodes/scbmc/build_cuda_clang_debug/_deps/generic-src
> -internal-isystem
> /home/aznb/.linuxbrew/lib/gcc/x86_64-unknown-linux-gnu/5.5.0/../../../../include/c++/5.5.0
> -internal-isystem
> /home/aznb/.linuxbrew/lib/gcc/x86_64-unknown-linux-gnu/5.5.0/../../../../include/c++/5.5.0/x86_64-unknown-linux-gnu
> -internal-isystem
> /home/aznb/.linuxbrew/lib/gcc/x86_64-unknown-linux-gnu/5.5.0/../../../../include/c++/5.5.0/backward
> -internal-isystem
> /home/aznb/.linuxbrew/lib/gcc/x86_64-unknown-linux-gnu/5.5.0/../../../../include/c++/5.5.0
> -internal-isystem
> /home/aznb/.linuxbrew/lib/gcc/x86_64-unknown-linux-gnu/5.5.0/../../../../include/c++/5.5.0/x86_64-unknown-linux-gnu
> -internal-isystem
> /home/aznb/.linuxbrew/lib/gcc/x86_64-unknown-linux-gnu/5.5.0/../../../../include/c++/5.5.0/backward
> -internal-isystem /usr/local/include -internal-isystem
> /home/aznb/.linuxbrew/Cellar/llvm/HEAD-48aefa8/lib/clang/9.0.0/include
> -internal-externc-isystem /include -internal-externc-isystem /usr/include
> -internal-isystem /usr/local/include -internal-isystem
> /home/aznb/.linuxbrew/Cellar/llvm/HEAD-48aefa8/lib/clang/9.0.0/include
> -internal-externc-isystem /include -internal-externc-isystem /usr/include
> -O0 -std=c++17 -fdeprecated-macro -fno-dwarf-directory-asm
> -fdebug-compilation-dir /home/aznb/mycodes/scbmc/build_cuda_clang_debug
> -ferror-limit 19 -fmessage-length 0 -fobjc-runtime=gcc -fcxx-exceptions
> -fexceptions -fdiagnostics-show-option -o
> /tmp/60663577.1.login.q/testparticles-1d20c4.s -x cuda
> /home/aznb/mycodes/scbmc/testparticles.cpp
>
> Both of these commands were shown in the error log. How do I replace my
> original cpp files with the two *.cu files automatically generated by llvm
> in the above command to reproduce the bug?
>
> Thanks,
> Char
>
>
> At 2019-02-26 09:22:35, "Alexey Bataev" <a.bataev at outlook.com>
> <a.bataev at outlook.com> wrote:
>
> Hi Char, unfortunately I cannot help you with these crashes, because they
> caused not by clang /LLVM, but the NVidia's PTX-to-SASS translator ptxas.
> It is ptxas who crashes and I can't do anything about this. You need to
> report the bug to NVidia, but you need to manually run the ptxas tool with
> the generated  .s file. Sometimes it helps to compile the code
> sequentially, not using the parallel builds. Plus, those crashes may
> disappear from time to time.
>
> Best regards,
> Alexey Bataev
>
> 25 февр. 2019 г., в 19:59, treinz <treinz at 163.com> написал(а):
>
> Hi Alexey,
>
> Thanks for the great work! The version I checked out works most of the
> time. But I do encounter crashes sometimes. I can't file a bug report on
> https://bugs.llvm.org/ because I don't have an account. I sent an email
> to bugs-admin at lists.llvm.org for an account already but I haven't heard
> back. Meanwhile, can you take a look at the issue? I'm attaching the bug
> report files here -- the clang_error.log has the verbose output from clang
> and the other files are generated automatically by clang upon the crash.
> I'm using the above-mentioned commit
> 48aefa8877713616802d9c90b63f86fe50b9a101 from github mirror. The bug is
> reproducible on my machine with a nvidia RTX2080 card (sm=Turing75).
>
> Thanks,
> Char
>
> At 2019-01-24 03:25:39, "Alexey Bataev" <a.bataev at outlook.com> wrote:
>
> Yes, this one.
>
> -------------
> Best regards,
> Alexey Bataev
>
> 23.01.2019 14:17, treinz via llvm-dev пишет:
>
> Hi Alexey,
>
> Thanks for working on this. I assume the last commit you mentioned is:
>
> commit 48aefa8877713616802d9c90b63f86fe50b9a101 (HEAD -> master,
> origin/master, origin/HEAD)
> Author: Alexey Bataev <a.bataev at hotmail.com> <a.bataev at hotmail.com>
> Date:   Wed Jan 23 18:59:54 2019 +0000
>
>     [DEBUGINFO, NVPTX] Enable support for the debug info on NVPTX target.
>
>     Enable full support for the debug info.
>
>     Differential revision: https://reviews.llvm.org/D46189
>
>     git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@351974
> 91177308-0d34-0410-b5e6-96231b3b80d8
>
> I'll check this one out.
>
> Thanks,
> Char
>
> At 2019-01-24 03:01:18, "Alexey Bataev" <a.bataev at outlook.com>
> <a.bataev at outlook.com> wrote:
>
> Hi Char, I found the problem, for some reason the last patch was applied
> correctly. Just committed the fixed version. Tried to compile axpy.cu,
> everything works.
>
> -------------
> Best regards,
> Alexey Bataev
>
> 23.01.2019 13:37, treinz пишет:
>
> Hi Alexey,
>
> I tried the b7195a6 from the llvm github mirror, which does include your
> commit D46189 <https://reviews.llvm.org/D46189> (see below). But it can't
> compile the example program on
> https://llvm.org/docs/CompileCudaWithLLVM.html#invoking-clang
> <https://llvm.org/docs/CompileCudaWithLLVM.html#invoking-clang.> -- the
> error is:
>
> [aznb at asp testcuda]$ clang++ axpy.cu -g -o axpy --cuda-gpu-arch=sm_61
> -lcudart_static -ldl -lrt -pthread -v
> clang version 9.0.0 (https://git.llvm.org/git/clang.git
> 4566ed0d7c076ad061168f7c6cb5fa3a793614a8) (
> https://git.llvm.org/git/llvm.git
> b7195a6d8d9064c4fac6a7b91826de80df394f69)
> Target: x86_64-unknown-linux-gnu
> Thread model: posix
> InstalledDir: /home/aznb/.linuxbrew/bin
> Found candidate GCC installation:
> /home/aznb/.linuxbrew/bin/../lib/gcc/x86_64-unknown-linux-gnu/5.5.0
> Found candidate GCC installation: /usr/lib/gcc/x86_64-redhat-linux/4.4.4
> Found candidate GCC installation: /usr/lib/gcc/x86_64-redhat-linux/4.4.7
> Selected GCC installation:
> /home/aznb/.linuxbrew/bin/../lib/gcc/x86_64-unknown-linux-gnu/5.5.0
> Candidate multilib: .;@m64
> Selected multilib: .;@m64
> Found CUDA installation:
> /net/vol3/software/modules-sw/cuda/10.0/Linux/RHEL6/x86_64, version 10.0
>  "/home/aznb/mycodes/testcuda -ferror-limit 19 -fmessage-length 0 -pthread
> -fobjc-runtime=gcc -fcxx-exceptions -fexceptions -fdiagnostics-show-option
> -o /tmp/59224042.1.login.q/axpy-560f45.s -x cuda axpy.cu
> clang -cc1 version 9.0.0 based upon LLVM 9.0.0svn default target
> x86_64-unknown-linux-gnu
> ignoring nonexistent directory "/include"
> ignoring nonexistent directory "/include"
> ignoring duplicate directory
> "/home/aznb/.linuxbrew/bin/../lib/gcc/x86_64-unknown-linux-gnu/5.5.0/../../../../include/c++/5.5.0"
> ignoring duplicate directory
> "/home/aznb/.linuxbrew/bin/../lib/gcc/x86_64-unknown-linux-gnu/5.5.0/../../../../include/c++/5.5.0/x86_64-unknown-linux-gnu"
> ignoring duplicate directory
> "/home/aznb/.linuxbrew/bin/../lib/gcc/x86_64-unknown-linux-gnu/5.5.0/../../../../include/c++/5.5.0/backward"
> ignoring duplicate directory "/usr/local/include"
> ignoring duplicate directory
> "/home/aznb/.linuxbrew/Cellar/llvm/HEAD-b7195a6/lib/clang/9.0.0/include"
> ignoring duplicate directory "/usr/include"
> #include "..." search starts here:
> #include <...> search starts here:
>
>  /home/aznb/.linuxbrew/Cellar/llvm/HEAD-b7195a6/lib/clang/9.0.0/include/cuda_wrappers
>  /net/vol3/software/modules-sw/cuda/10.0/Linux/RHEL6/x86_64/include
>
>  /home/aznb/.linuxbrew/bin/../lib/gcc/x86_64-unknown-linux-gnu/5.5.0/../../../../include/c++/5.5.0
>
>  /home/aznb/.linuxbrew/bin/../lib/gcc/x86_64-unknown-linux-gnu/5.5.0/../../../../include/c++/5.5.0/x86_64-unknown-linux-gnu
>
>  /home/aznb/.linuxbrew/bin/../lib/gcc/x86_64-unknown-linux-gnu/5.5.0/../../../../include/c++/5.5.0/backward
>  /usr/local/include
>  /home/aznb/.linuxbrew/Cellar/llvm/HEAD-b7195a6/lib/clang/9.0.0/include
>  /usr/include
> End of search list.
>  "/net/vol3/software/modules-sw/cuda/10.0/Linux/RHEL6/x86_64/bin/ptxas"
> -m64 -g --dont-merge-basicblocks --return-at-end -v --gpu-name sm_61
> --output-file /tmp/59224042.1.login.q/axpy-1ebb06.o
> /tmp/59224042.1.login.q/axpy-560f45.s
> ptxas /tmp/59224042.1.login.q/axpy-560f45.s, line 290; fatal   : Parsing
> error near '{': syntax error
> ptxas fatal   : Ptx assembly aborted due to errors
> clang-9: error: ptxas command failed with exit code 255 (use -v to see
> invocation)
>
> Maybe it's related to the illegal assembly code mentioned in
> https://reviews.llvm.org/D46189 Any idea what's going on? I'm including
> other people to see if they have any suggestion.
> https://reviews.llvm.org/D46189 also mentioned that this is fixed but has
> the fixed been merged in the trunk yet?
>
> BTW, github mirror's b7195a6 does include your commit about the debug info
> on nvptx:
>
> commit d77902a49a06890b97e33515d346c6e4df6b756b
> Author: Alexey Bataev <a.bataev at hotmail.com> <a.bataev at hotmail.com>
> Date:   Tue Jan 22 17:43:37 2019 +0000
>
>     [DEBUGINFO, NVPTX] Enable support for the debug info on NVPTX target.
>
>     Summary: Enable full support for the debug info.
>
>     Reviewers: echristo
>
>     Subscribers: jholewinski, aprantl, JDevlieghere, llvm-commits
>
>     Differential Revision: https://reviews.llvm.org/D46189
>
>     git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@351846
> 91177308-0d34-0410-b5e6-96231b3b80d8
>
> Thanks,
> Char
>
> 在 2019-01-23 07:59:12，"Alexey Bataev" <a.bataev at outlook.com>
> <a.bataev at outlook.com> 写道：
>
> Hi Char, I don't know how often it is updated, but most probably it is
> already updated.
>
> Best regards,
> Alexey Bataev
>
> 22 янв. 2019 г., в 17:46, treinz <treinz at 163.com> написал(а):
>
>
> Hi Alexey,
>
> Thank you for letting me know. Can I assume the the github mirror is
> bumped to 9.0 and should contain the commit you mentioned? Just want to
> make sure I'm looking at the right repo.
>
> Thanks,
> Char
>
>
> 在 2019-01-23 01:46:44，"Alexey Bataev" <a.bataev at outlook.com> 写道：
>
> Hi, debug info for the NVPTX is committed. It is not a part of 8.0 RC1,
> unfortunately, only in 9.0 trunk.
>
> -------------
> Best regards,
> Alexey Bataev
>
> 14.12.2018 17:08, Alexey Bataev пишет:
>
> Actually, we need to commit just 2 more patches to enable basic debug info
> support for NVPTX. So, I hope, it is going to be the part of the next 8.0
> release. It won't be backported to 7.0 definitely.
> Sure, I will let you know when the patches are committed to the trunk, no
> problems.
>
> Best regards,
> Alexey Bataev
>
> 14 дек. 2018 г., в 16:55, treinz <treinz at 163.com> написал(а):
>
> Are you planning to release this as soon as it's ready or you want to make
> it into a major release? Is it possible to let me know (maybe by replying
> to this thread) once the code is ready? I know sometimes it takes a while
> to get things in the major release. I greatly appreciate your work on this!
>
> Thanks,
> Char
>
> 在 2018-12-15 05:19:50，"Alexey Bataev" <a.bataev at outlook.com> 写道：
>
> Hi Char, sorry, you need to wait a little bit. It is almost ready, but not
> yet. For now, use nvcc if you need debug info for Cuda.
>
> -------------
> Best regards,
> Alexey Bataev
>
> 14.12.2018 14:33, treinz пишет:
>
> Hi Alex, Eric and Valentin,
>
> Thanks for the information. I don't mean to push this but I'm in desperate
> need of debugging some cuda code. I'm not familiar with the llvm internal
> but it sounds like there's at least line info now, right? If so, can you
> point me to a branch of llvm that can help tracing the bug down to certain
> line of code. I believe my bug is simply a write/read out of array boundary.
>
> Thanks,
> Char
>
> 在 2018-12-05 07:15:28，"Alexey Bataev" <a.bataev at hotmail.com>
> <a.bataev at hotmail.com> 写道：
>
> Hi, yes, these patches are required to have tne basic debug info support.
> At least 2 more patches are required to be able to get values of the
> variables without additional manual data type casting in cuda-gdb.
>
> Best regards,
> Alexey Bataev
>
> 4 дек. 2018 г., в 18:06, Eric Christopher <echristo at gmail.com> написал(а):
>
> Adding Alexey here who has been driving this effort in llvm.
>
> There are about 5 patches waiting on my review:
>
>    -: https://reviews.llvm.org/D54320
>    -: https://reviews.llvm.org/D46189
>    -: https://reviews.llvm.org/D51554
>    -: https://reviews.llvm.org/D46061
>    -: https://reviews.llvm.org/D45784
>
> After which I think we're good.
>
> -eric
>
> On Mon, Dec 3, 2018 at 6:29 PM Valentin Churavy via llvm-dev <
> llvm-dev at lists.llvm.org> wrote:
>
>> AFAIK there is work under way from IBM (couple of PRs open), but yes
>> Clang 7.0 doesn't produce the necessary information.
>>
>> -V
>>
>> On Fri, Nov 30, 2018, 14:58 treinz via llvm-dev <llvm-dev at lists.llvm.org
>> wrote:
>>
>>> Hi all,
>>> I found this
>>> http://lists.llvm.org/pipermail/llvm-dev/2017-November/118871.html when
>>> googling about compiling CUDA code using llvm. Is it still the case that
>>> one can't step into CUDA kernel code compiled by llvm in cuda-gdb? I'm
>>> using clang 7.0.
>>>
>>> Thanks,
>>> Char
>>>
>>>
>>>
>>> _______________________________________________
>>> LLVM Developers mailing list
>>> llvm-dev at lists.llvm.org
>>> http://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev
>>>
>> _______________________________________________
>> LLVM Developers mailing list
>> llvm-dev at lists.llvm.org
>> http://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev
>>
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-- 
--Artem Belevich
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