Allocating zero size View

[hcedwar]

Potential bug with allocating zero size View. Debug output shared by a user.

Program received signal SIGSEGV, Segmentation fault.
0x0000000008bc8f37 in
Kokkos::Experimental::Impl::SharedAllocationRecord<Kokkos::CudaUVMSpace,
void>::SharedAllocationRecord (this=0x26210120, arg_space=...,
arg_label=..., arg_alloc_size=0,
arg_dealloc=0x7bb565a <Kokkos::Experimental::Impl::(anonymous
namespace)::deallocate<Kokkos::CudaUVMSpace,
Kokkos::Experimental::Impl::ViewValueFunctor<Kokkos::Cuda,
Kokkos::pair<int, int>, false>

(Kokkos::Experimental::Impl::SharedAllocationRecord<void, void>*)>) at
/home/mbetten/Trilinos/Trilinos/packages/kokkos/core/src/Cuda/Kokkos_CudaSpace.cpp:497
497 RecordBase::m_alloc_ptr->m_record = this ;
(cuda-gdb) where

0 0x0000000008bc8f37 in

Kokkos::Experimental::Impl::SharedAllocationRecord<Kokkos::CudaUVMSpace,
void>::SharedAllocationRecord (this=0x26210120, arg_space=...,
arg_label=..., arg_alloc_size=0,
arg_dealloc=0x7bb565a <Kokkos::Experimental::Impl::(anonymous
namespace)::deallocate<Kokkos::CudaUVMSpace,
Kokkos::Experimental::Impl::ViewValueFunctor<Kokkos::Cuda,
Kokkos::pair<int, int>, false>
(Kokkos::Experimental::Impl::SharedAllocationRecord<void, void>*)>) at
/home/mbetten/Trilinos/Trilinos/packages/kokkos/core/src/Cuda/Kokkos_CudaSpace.cpp:497

1 0x0000000007bb4ff9 in

Kokkos::Experimental::Impl::SharedAllocationRecord<Kokkos::CudaUVMSpace,
Kokkos::Experimental::Impl::ViewValueFunctor<Kokkos::Cuda,
Kokkos::pair<int, int>, false> >::SharedAllocationRecord (this=0x26210120,
arg_space=..., arg_label=..., arg_alloc=0) at
/home/mbetten/Trilinos/Trilinos/packages/kokkos/core/src/impl/KokkosExp_SharedAlloc.hpp:209

2 0x0000000007bb49b6 in

Kokkos::Experimental::Impl::SharedAllocationRecord<Kokkos::CudaUVMSpace,
Kokkos::Experimental::Impl::ViewValueFunctor<Kokkos::Cuda,
Kokkos::pair<int, int>, false> >::allocate (arg_space=..., arg_label=...,
arg_alloc=0) at
/home/mbetten/Trilinos/Trilinos/packages/kokkos/core/src/impl/KokkosExp_SharedAlloc.hpp:234

3 0x0000000007bb32f0 in

Kokkos::Experimental::Impl::ViewMapping<Kokkos::Experimental::ViewTraits<Kokkos::pair<int,
int>*, Kokkos::LayoutLeft, Kokkos::Device<Kokkos::Cuda,
Kokkos::CudaUVMSpace>, Kokkos::MemoryTraits<0u> >,
void>::allocate_shared<std::string,
Kokkos::Experimental::Impl::WithoutInitializing_t,
std::integral_constant<unsigned int, 0u>, Kokkos::CudaUVMSpace,
Kokkos::Cuda> (this=0x7fffffff4fa8, arg_prop=..., arg_layout=...)
at
/home/mbetten/Trilinos/Trilinos/packages/kokkos/core/src/impl/KokkosExp_ViewMapping.hpp:2552

4 0x0000000007bae864 in Kokkos::Experimental::View<Kokkos::pair<int,

int>*, Kokkos::LayoutLeft, Kokkos::Device<Kokkos::Cuda,
Kokkos::CudaUVMSpace>, Kokkos::MemoryTraits<0u> >::View<std::string,
Kokkos::Experimental::Impl::WithoutInitializing_t>(Kokkos::Experimental::Impl::ViewCtorProp<std::string,
Kokkos::Experimental::Impl::WithoutInitializing_t> const&,
std::enable_if<!Kokkos::Experimental::Impl::ViewCtorProp<std::string,
Kokkos::Experimental::Impl::WithoutInitializing_t>::has_pointer,
Kokkos::LayoutLeft>::type const&) (this=0x7fffffff4fa0, arg_prop=...,
arg_layout=...) at
/home/mbetten/Trilinos/Trilinos/packages/kokkos/core/src/KokkosExp_View.hpp:1225

5 0x0000000007ba9359 in Kokkos::Experimental::View<Kokkos::pair<int,

int>*, Kokkos::LayoutLeft, Kokkos::Device<Kokkos::Cuda,
Kokkos::CudaUVMSpace>, Kokkos::MemoryTraits<0u> >::View
(this=0x7fffffff4fa0, arg_prop=..., arg_N0=0,
arg_N1=0, arg_N2=0, arg_N3=0, arg_N4=0, arg_N5=0, arg_N6=0,
arg_N7=0) at
/home/mbetten/Trilinos/Trilinos/packages/kokkos/core/src/KokkosExp_View.hpp:1344

[hcedwar]

Added unit test for zero length allocation and CUDA-UVM, test passes.
Will add precondition-checks at potential failure points in this stack to attempt to catch this kind of error before a segfault.

[hcedwar]

Issue was downstream bug in Tpetra.
trilinos/Trilinos#227
Adding a few precondition checks to shared allocation tracker that were motivated by this issue.