Segfault from tests

[tpadioleau]

In the following setup:

• File sum.hpp

#pragma once

#include <ddc/ddc.hpp>

struct DDimX
{
};

inline int sum(ddc::ChunkSpan<
               const int,
               ddc::DiscreteDomain<DDimX>,
               Kokkos::layout_right,
               Kokkos::DefaultExecutionSpace::memory_space> const& chk_span)
{
    return ddc::parallel_transform_reduce(
            chk_span.domain(),
            0,
            ddc::reducer::sum<int>(),
            KOKKOS_LAMBDA(ddc::DiscreteElement<DDimX> const ix) { return chk_span(ix); });
}

• File sum_version_a.cpp

#include <ddc/ddc.hpp>

#include <gtest/gtest.h>

#include "sum.hpp"

TEST(SumVersionA, Small)
{
    ddc::DiscreteVector<DDimX> const n(10);
    ddc::DiscreteDomain<DDimX> const gridvx = ddc::init_trivial_space(n);

    ddc::Chunk quadrature_coeffs(gridvx, ddc::DeviceAllocator<int>());
    ddc::parallel_fill(quadrature_coeffs, 1);

    EXPECT_EQ(sum(quadrature_coeffs.span_cview()), n.value());
}

• File sum_version_b.cpp

#include <ddc/ddc.hpp>

#include <gtest/gtest.h>

#include "sum.hpp"

TEST(SumVersionB, Small)
{
    ddc::DiscreteVector<DDimX> const n(10);
    ddc::DiscreteDomain<DDimX> const gridvx = ddc::init_trivial_space(n);

    ddc::Chunk quadrature_coeffs(gridvx, ddc::DeviceAllocator<int>());
    ddc::parallel_fill(quadrature_coeffs, 1);

    EXPECT_EQ(sum(quadrature_coeffs.span_cview()), n.value());
}

Compiled with the following CMakeLists.txt

cmake_minimum_required(VERSION 3.22)

include(GoogleTest)

add_executable(reproducer
    sum_version_a.cpp
    sum_version_b.cpp
    ../main.cpp
)

target_link_libraries(reproducer
    PUBLIC
        GTest::gtest
        DDC::core
)

gtest_discover_tests(reproducer DISCOVERY_MODE PRE_TEST)

We have a segfault if we run the tests with ctest but not with the executable with the following backtrace:

#0  0x0000000000000000 in ?? ()
#1  0x00000000004133b6 in __nv_hdl_wrapper_t<false, false, false, __nv_dl_tag<int (*)(ddc::ChunkSpan<int const, ddc::DiscreteDomain<DDimX>, Kokkos::layout_right, Kokkos::CudaSpace> const&), &(sum(ddc::ChunkSpan<int const, ddc::DiscreteDomain<DDimX>, Kokkos::layout_right, Kokkos::CudaSpace> const&)), 1u>, int(ddc::DiscreteElement<DDimX>), ddc::ChunkSpan<int const, ddc::DiscreteDomain<DDimX>, Kokkos::layout_right, Kokkos::CudaSpace> const>::__nv_hdl_wrapper_t (in=..., this=0x7fffffffbcb8) at nvcc_internal_extended_lambda_implementation:253
#2  ddc::detail::TransformReducerKokkosLambdaAdapter<ddc::reducer::sum<int>, __nv_hdl_wrapper_t<false, false, false, __nv_dl_tag<int (*)(ddc::ChunkSpan<int const, ddc::DiscreteDomain<DDimX>, Kokkos::layout_right, Kokkos::CudaSpace> const&), &(sum(ddc::ChunkSpan<int const, ddc::DiscreteDomain<DDimX>, Kokkos::layout_right, Kokkos::CudaSpace> const&)), 1u>, int(ddc::DiscreteElement<DDimX>), ddc::ChunkSpan<int const, ddc::DiscreteDomain<DDimX>, Kokkos::layout_right, Kokkos::CudaSpace> const>, ddc::DiscreteDomain<DDimX>, std::integer_sequence<unsigned long, 0ul> >::TransformReducerKokkosLambdaAdapter (support=..., f=..., r=..., this=0x7fffffffbcb0) at /home/TP026749/ddc/include/ddc/parallel_transform_reduce.hpp:107
#3  ddc::detail::transform_reduce_kokkos<Kokkos::Cuda, ddc::DiscreteDomain<DDimX>, int, ddc::reducer::sum<int>, __nv_hdl_wrapper_t<false, false, false, __nv_dl_tag<int (*)(ddc::ChunkSpan<int const, ddc::DiscreteDomain<DDimX>, Kokkos::layout_right, Kokkos::CudaSpace> const&), &(sum(ddc::ChunkSpan<int const, ddc::DiscreteDomain<DDimX>, Kokkos::layout_right, Kokkos::CudaSpace> const&)), 1u>, int(ddc::DiscreteElement<DDimX>), ddc::ChunkSpan<int const, ddc::DiscreteDomain<DDimX>, Kokkos::layout_right, Kokkos::CudaSpace> const> > (label=..., execution_space=..., 
    domain=..., neutral=neutral@entry=0, reduce=..., transform=...) at /home/TP026749/ddc/include/ddc/parallel_transform_reduce.hpp:149
#4  0x000000000041358c in ddc::parallel_transform_reduce<Kokkos::Cuda, ddc::DiscreteDomain<DDimX>, int, ddc::reducer::sum<int>, __nv_hdl_wrapper_t<false, false, false, __nv_dl_tag<int (*)(ddc::ChunkSpan<int const, ddc::DiscreteDomain<DDimX>, Kokkos::layout_right, Kokkos::CudaSpace> const&), &(sum(ddc::ChunkSpan<int const, ddc::DiscreteDomain<DDimX>, Kokkos::layout_right, Kokkos::CudaSpace> const&)), 1u>, int(ddc::DiscreteElement<DDimX>), ddc::ChunkSpan<int const, ddc::DiscreteDomain<DDimX>, Kokkos::layout_right, Kokkos::CudaSpace> const> > (transform=..., 
    reduce=..., neutral=0, domain=..., execution_space=..., label=...) at /home/TP026749/ddc/include/ddc/parallel_transform_reduce.hpp:182
#5  ddc::parallel_transform_reduce<ddc::DiscreteDomain<DDimX>, int, ddc::reducer::sum<int>, __nv_hdl_wrapper_t<false, false, false, __nv_dl_tag<int (*)(ddc::ChunkSpan<int const, ddc::DiscreteDomain<DDimX>, Kokkos::layout_right, Kokkos::CudaSpace> const&), &(sum(ddc::ChunkSpan<int const, ddc::DiscreteDomain<DDimX>, Kokkos::layout_right, Kokkos::CudaSpace> const&)), 1u>, int(ddc::DiscreteElement<DDimX>), ddc::ChunkSpan<int const, ddc::DiscreteDomain<DDimX>, Kokkos::layout_right, Kokkos::CudaSpace> const> > (domain=..., neutral=neutral@entry=0, reduce=..., 
    transform=...) at /home/TP026749/ddc/include/ddc/parallel_transform_reduce.hpp:258
#6  0x0000000000413def in sum (chk_span=...) at /home/TP026749/ddc/tests/nvcc_reproducer/sum.hpp:19
#7  SumVersionB_Small_Test::TestBody (this=<optimized out>) at /home/TP026749/ddc/tests/nvcc_reproducer/sum_version_b.cpp:19
#8  0x00007ffff5b5e2dd in void testing::internal::HandleExceptionsInMethodIfSupported<testing::Test, void>(testing::Test*, void (testing::Test::*)(), char const*) ()
   from /data/gyselarunner/spack-0.23.0/var/spack/environments/gyselalibxx-env-cuda-candidate/.spack-env/view/lib64/libgtest.so.1.14.0
#9  0x00007ffff5b3fffe in testing::Test::Run() () from /data/gyselarunner/spack-0.23.0/var/spack/environments/gyselalibxx-env-cuda-candidate/.spack-env/view/lib64/libgtest.so.1.14.0
#10 0x00007ffff5b401b5 in testing::TestInfo::Run() () from /data/gyselarunner/spack-0.23.0/var/spack/environments/gyselalibxx-env-cuda-candidate/.spack-env/view/lib64/libgtest.so.1.14.0
#11 0x00007ffff5b4046d in testing::TestSuite::Run() () from /data/gyselarunner/spack-0.23.0/var/spack/environments/gyselalibxx-env-cuda-candidate/.spack-env/view/lib64/libgtest.so.1.14.0
#12 0x00007ffff5b548c1 in testing::internal::UnitTestImpl::RunAllTests() ()
   from /data/gyselarunner/spack-0.23.0/var/spack/environments/gyselalibxx-env-cuda-candidate/.spack-env/view/lib64/libgtest.so.1.14.0
#13 0x00007ffff5b40544 in testing::UnitTest::Run() () from /data/gyselarunner/spack-0.23.0/var/spack/environments/gyselalibxx-env-cuda-candidate/.spack-env/view/lib64/libgtest.so.1.14.0
#14 0x00000000004147c0 in RUN_ALL_TESTS () at /data/gyselarunner/spack-0.23.0/var/spack/environments/gyselalibxx-env-cuda-candidate/.spack-env/view/include/gtest/gtest.h:2317
#15 main (argc=<optimized out>, argv=0x7fffffffc1d8) at /home/TP026749/ddc/tests/main.cpp:16

This happened with gcc@12, cuda@12 and with at least O1 optimisation enabled.

[tpadioleau]

Could not reproduce with a Kokkos equivalent example so far.

[tpadioleau]

See branch nvcc_reproducer:

• the tests can be compiled with cmake --build build --target reproducer --target reproducer2,
• the tests can be run with ctest --test-dir build -R Sum --verbose.