KJ16609/gcc
1
0
Fork 0
mirror of https://gcc.gnu.org/git/gcc.git synced 2026-02-21 19:35:28 -05:00
Code Issues Packages Projects Releases Wiki Activity
225,413 Commits 79 Branches 206 Tags
723b18ce3dd24ebcbb6426fb40a375642477123f
Commit Graph

2 Commits

Author SHA1 Message Date
Andrew Stubbs
723b18ce3d libgomp, amdgcn: Implement Managed Memory 
This patch implements "managed" memory for AMD GCN GPUs in OpenMP.  It
builds on the support added to the NVPTX libgomp for CUDA Managed Memory, a
week or two ago.

These features were first posted here a few years ago, as part of a larger
Unified Shared Memory patch series, and then in a slightly changed version just
over a year ago.  Hopefully this time the controversial bits have been removed.

Since we do not use HIP we cannot use hipMallocManaged, so this patch attempts
to replicate the same effect by setting the appropriate attributes.  This works
on more devices than support proper USM, but still I cannot be sure that the
settings are correct for every device out there (I have tested on gfx900,
gfx906, gfx908, gfx90a, and gfx1100).

The HSA header file update uses the most recent files relicensed for us by AMD,
at the time of the first patch posting.  Those files have certainly moved on in
the upstream sources, but I did not ask to get those relicensed.

include/ChangeLog:

	* hsa.h: Import newer version.
	* hsa_ext_amd.h: Likewise.
	* hsa_ext_image.h: Likewise.

libgomp/ChangeLog:

	* Makefile.in: Regenerate.
	* libgomp-plugin.h (gomp_simple_alloc_init_context): New prototype.
	(gomp_simple_alloc_register_memory): New prototype.
	(gomp_simple_alloc): New prototype.
	(gomp_simple_free): New prototype.
	(gomp_simple_realloc): New prototype.
	* libgomp.h (gomp_simple_alloc_init_context): Move to libgomp-plugin.h.
	(gomp_simple_alloc_register_memory): Likewise.
	(gomp_simple_alloc): Likewise.
	(gomp_simple_free): Likewise.
	(gomp_simple_realloc): Likewise.
	* libgomp.texi: Update AMD managed memory description.
	* plugin/Makefrag.am (libgomp_plugin_gcn_la_SOURCES): Add
	simple-allocator.c and plugin/mutex.c.
	* plugin/plugin-gcn.c: Include sys/mman.h and unistd.h.
	(struct hsa_runtime_fn_info): Add hsa_amd_svm_attributes_set_fn.
	(dump_hsa_system_info): Add HSA_AMD_SYSTEM_INFO_SVM_SUPPORTED and
	HSA_AMD_SYSTEM_INFO_SVM_ACCESSIBLE_BY_DEFAULT to the GCN_DEBUG output.
	(init_hsa_runtime_functions): Add hsa_amd_svm_attributes_set.
	(isa_matches_agent): Add a new error message for the case where the
	ISA doesn't match but the name does.
	(managed_ctx): New variable.
	(managed_heap_create): New function.
	(GOMP_OFFLOAD_managed_alloc): Likewise.
	(GOMP_OFFLOAD_managed_free): Likewise.
	* simple-allocator.c (gomp_fatal): New macro.
	* testsuite/lib/libgomp.exp (check_effective_target_omp_managedmem):
	Add amdgcn support checker.
	(check_effective_target_offload_target_amdgcn_with_xnack): New.
	* testsuite/libgomp.c-c++-common/requires-4.c: Ignore xnack warning.
	* testsuite/libgomp.c-c++-common/requires-4a.c: Ignore xnack warning.
	* testsuite/libgomp.c-c++-common/requires-5.c: Ignore xnack warning.
	* testsuite/libgomp.c++/alloc-managed-1.C: Add -mxnack=on, if needed.
	* testsuite/libgomp.c/alloc-managed-1.c: Likewise.
	* testsuite/libgomp.c/alloc-managed-2.c: Likewise.
	* testsuite/libgomp.c/alloc-managed-3.c: Likewise.
	* testsuite/libgomp.c/alloc-managed-4.c: Likewise.
	* testsuite/libgomp.fortran/alloc-managed-1.f90: Likewise.
	* plugin/mutex.c: New file.
 2025-12-01 12:03:35 +00:00
Andrew Stubbs
62174ec27b openmp, nvptx: ompx_gnu_managed_mem_alloc 
This adds support for using Cuda Managed Memory with omp_alloc.  AMD support
will be added in a future patch.

There is one new predefined allocator, "ompx_gnu_managed_mem_alloc", plus a
corresponding memory space, which can be used to allocate memory in the
"managed" space.

The nvptx plugin is modified to make the necessary Cuda calls, via two new
(optional) plugin interfaces.

gcc/fortran/ChangeLog:

	* openmp.cc (is_predefined_allocator): Use GOMP_OMP_PREDEF_ALLOC_MAX
	and GOMP_OMPX_PREDEF_ALLOC_MIN/MAX instead of hardcoded values in the
	comment.

include/ChangeLog:

	* cuda/cuda.h (cuMemAllocManaged): Add declaration and related
	CU_MEM_ATTACH_GLOBAL flag.
	* gomp-constants.h (GOMP_OMPX_PREDEF_ALLOC_MAX): Update to 201.
	(GOMP_OMP_PREDEF_MEMSPACE_MAX): New constant.
	(GOMP_OMPX_PREDEF_MEMSPACE_MIN): New constant.
	(GOMP_OMPX_PREDEF_MEMSPACE_MAX): New constant.

libgomp/ChangeLog:

	* allocator.c (ompx_gnu_max_predefined_alloc): Update to
	ompx_gnu_managed_mem_alloc.
	(_Static_assert): Fix assertion messages for allocators and add
	new assertions for memspace constants.
	(omp_max_predefined_mem_space): New define.
	(ompx_gnu_min_predefined_mem_space): New define.
	(ompx_gnu_max_predefined_mem_space): New define.
	(MEMSPACE_ALLOC): Add check for non-standard memspaces.
	(MEMSPACE_CALLOC): Likewise.
	(MEMSPACE_REALLOC): Likewise.
	(MEMSPACE_VALIDATE): Likewise.
	(predefined_ompx_gnu_alloc_mapping): Add ompx_gnu_managed_mem_space.
	(omp_init_allocator): Add ompx_gnu_managed_mem_space validation.
	* config/gcn/allocator.c (gcn_memspace_alloc): Add check for
	non-standard memspaces.
	(gcn_memspace_calloc): Likewise.
	(gcn_memspace_realloc): Likewise.
	(gcn_memspace_validate): Update to validate standard vs non-standard
	memspaces.
	* config/linux/allocator.c (linux_memspace_alloc): Add managed
	memory space handling.
	(linux_memspace_calloc): Likewise.
	(linux_memspace_free): Likewise.
	(linux_memspace_realloc): Likewise (returns NULL for fallback).
	* config/nvptx/allocator.c (nvptx_memspace_alloc): Add check for
	non-standard memspaces.
	(nvptx_memspace_calloc): Likewise.
	(nvptx_memspace_realloc): Likewise.
	(nvptx_memspace_validate): Update to validate standard vs non-standard
	memspaces.
	* env.c (parse_allocator): Add ompx_gnu_managed_mem_alloc,
	ompx_gnu_managed_mem_space, and some static asserts so I don't forget
	them again.
	* libgomp-plugin.h (GOMP_OFFLOAD_managed_alloc): New declaration.
	(GOMP_OFFLOAD_managed_free): New declaration.
	* libgomp.h (gomp_managed_alloc): New declaration.
	(gomp_managed_free): New declaration.
	(struct gomp_device_descr): Add managed_alloc_func and
	managed_free_func fields.
	* libgomp.texi: Document ompx_gnu_managed_mem_alloc and
	ompx_gnu_managed_mem_space, add C++ template documentation, and
	describe NVPTX and AMD support.
	* omp.h.in: Add ompx_gnu_managed_mem_space and
	ompx_gnu_managed_mem_alloc enumerators, and gnu_managed_mem C++
	allocator template.
	* omp_lib.f90.in: Add Fortran bindings for new allocator and
	memory space.
	* omp_lib.h.in: Likewise.
	* plugin/cuda-lib.def: Add cuMemAllocManaged.
	* plugin/plugin-nvptx.c (nvptx_alloc): Add managed parameter to
	support cuMemAllocManaged.
	(GOMP_OFFLOAD_alloc): Move contents to ...
	(cleanup_and_alloc): ... this new function, and add managed support.
	(GOMP_OFFLOAD_managed_alloc): New function.
	(GOMP_OFFLOAD_managed_free): New function.
	* target.c (gomp_managed_alloc): New function.
	(gomp_managed_free): New function.
	(gomp_load_plugin_for_device): Load optional managed_alloc
	and managed_free plugin APIs.
	* testsuite/lib/libgomp.exp: Add check_effective_target_omp_managedmem.
	* testsuite/libgomp.c++/alloc-managed-1.C: New test.
	* testsuite/libgomp.c/alloc-managed-1.c: New test.
	* testsuite/libgomp.c/alloc-managed-2.c: New test.
	* testsuite/libgomp.c/alloc-managed-3.c: New test.
	* testsuite/libgomp.c/alloc-managed-4.c: New test.
	* testsuite/libgomp.fortran/alloc-managed-1.f90: New test.

Co-authored-by: Kwok Cheung Yeung <kcyeung@baylibre.com>
Co-authored-by: Thomas Schwinge <tschwinge@baylibre.com>
 2025-11-13 14:16:09 +00:00