As discussed in D105990, without this patch, `targetDataBegin`
determines whether to transfer data (as opposed to assuming it's in
shared memory) using the condition `!UseUSM || HasCloseModifier`.
However, this condition is broken if use of discrete memory was forced
by `omp_target_associate_ptr`. This patch extends
`unified_shared_memory/associate_ptr.c` to reveal this case, and it
fixes it using `!IsHostPtr` in `DeviceTy::getTargetPointer` to replace
this condition.
Reviewed By: grokos
Differential Revision: https://reviews.llvm.org/D107927
As discussed in D105990, without this patch, `targetDataEnd`
determines whether to transfer data or delete a device mapping (as
opposed to assuming it's in shared memory) using two different
conditions, each of which is broken for some cases:
1. `!(UNIFIED_SHARED_MEMORY && TgtPtrBegin == HstPtrBegin)`: The
broken case is rare: the device and host might happen to use the
same address for their mapped allocations. I don't know how to
write a test that's likely to reveal this case, but this patch does
fix it, as discussed below.
2. `!UNIFIED_SHARED_MEMORY || HasCloseModifier`: There are at least
two broken cases:
1. The `close` modifier might have been specified on an `omp
target enter data` but not the corresponding `omp target exit
data`, which thus might falsely assume a mapping is in shared
memory. The test `unified_shared_memory/close_enter_exit.c`
already has a missing deletion as a result, and this patch adds
a check for that. This patch also adds the new test
`close_member.c` to reveal a missing transfer and deletion.
2. Use of discrete memory might have been forced by
`omp_target_associate_ptr`, as in the test
`unified_shared_memory/api.c`. In the current `targetDataEnd`
implementation, this condition turns out not be used for this
case: because the reference count is infinite, a transfer is
possible only with an `always` modifier, and this condition is
never used in that case. To ensure it's never used for that
case in the future, this patch adds the test
`unified_shared_memory/associate_ptr.c`.
Fortunately, `DeviceTy::getTgtPtrBegin` already has a solution: it
reports whether the allocation was found in shared memory via the
variable `IsHostPtr`.
After this patch, `HasCloseModifier` is no longer used in
`targetDataEnd`, and I wonder if the `close` modifier is ever useful
on an `omp target data end`.
Reviewed By: grokos
Differential Revision: https://reviews.llvm.org/D107925
Add a `REQUIRES: unified_shared_memory` option to tests that use `#pragma omp requires unified_shared_memory`.
For CUDA, the feature tag is derived from LIBOMPTARGET_DEP_CUDA_ARCH which itself is derived using [[ https://cmake.org/cmake/help/latest/module/FindCUDA.html#commands | cuda_select_nvcc_arch_flags ]]. The latter determines which compute capability the GPU in the system supports. To ensure that this is the CUDA arch being used, we could also set the `-Xopenmp-target -march=` flag.
In the absence of an NVIDIA GPU, LIBOMPTARGET_DEP_CUDA_ARCH will be 35. That is, in that case we are assuming unified_shared_memory is not available. CUDA plugin testing could be disabled entirely in this case, but this currently depends on `LIBOMPTARGET_CAN_LINK_LIBCUDA OR LIBOMPTARGET_FORCE_DLOPEN_LIBCUDA`, not on whether the hardware is actually available.
For all other targets, nothing changes and we are assuming unified shared memory is available. This might need refinement if not the case.
This tries to fix the [[ http://meinersbur.de:8011/#/builders/143 | OpenMP Offloading Buildbot ]] that, although brand-new, only has a Pascal-generation (sm_61) GPU installed. Hence, tests that require unified shared memory are currently failing. I wish I had known in advance.
Reviewed By: protze.joachim, tianshilei1992
Differential Revision: https://reviews.llvm.org/D101498
This enables the runtime tests on amdgpu targets.
10 tests have been marked as XFAIL on amdgcn currently mostly due to
missing printf.
Reviewed By: protze.joachim
Differential Revision: https://reviews.llvm.org/D99656
This patch fuses the RUN lines for most libomptarget tests. The previous patch
D101315 created separate test targets for each supported offloading triple.
This patch updates the RUN lines in libomptarget tests to use a generic run
line independent of the offloading target selected for the lit instance.
In cases, where no RUN line was defined for a specific offloading target,
the corresponding target is declared as XFAIL. If it turns out that a test
actually supports the target, the XFAIL line can be removed.
Differential Revision: https://reviews.llvm.org/D101326
Summary:
This patch adds support for the close map modifier.
The close map modifier will overwrite the unified shared memory requirement and create a device copy of the data.
Reviewers: ABataev, Hahnfeld, caomhin, grokos, jdoerfert, AlexEichenberger
Reviewed By: Hahnfeld, AlexEichenberger
Subscribers: guansong, openmp-commits
Tags: #openmp
Differential Revision: https://reviews.llvm.org/D65340
llvm-svn: 368488
Summary:
This patch adds support for using unified memory in the case of regular maps that happen when a target region is offloaded to the device.
For cases where only a single version of the data is required then the host address can be used. When variables need to be privatized in any way or globalized, then the copy to the device is still required for correctness.
Reviewers: ABataev, jdoerfert, Hahnfeld, AlexEichenberger, caomhin, grokos
Reviewed By: Hahnfeld
Subscribers: mgorny, guansong, openmp-commits
Tags: #openmp
Differential Revision: https://reviews.llvm.org/D65001
llvm-svn: 368192
Joel E. Denny