cuda_async_view_memory_resource.hpp

/*
 * Copyright (c) 2021, NVIDIA CORPORATION.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
#pragma once
 
#include <rmm/cuda_device.hpp>
#include <rmm/cuda_stream_view.hpp>
#include <rmm/detail/cuda_util.hpp>
#include <rmm/detail/dynamic_load_runtime.hpp>
#include <rmm/detail/error.hpp>
#include <rmm/mr/device/device_memory_resource.hpp>
 
#include <thrust/optional.h>
 
#include <cuda_runtime_api.h>
 
#include <cstddef>
#include <limits>
 
#if CUDART_VERSION >= 11020  // 11.2 introduced cudaMallocAsync
#define RMM_CUDA_MALLOC_ASYNC_SUPPORT
#endif
 
namespace rmm::mr {
 
class cuda_async_view_memory_resource final : public device_memory_resource {
 public:
#ifdef RMM_CUDA_MALLOC_ASYNC_SUPPORT
 
  cuda_async_view_memory_resource(cudaMemPool_t valid_pool_handle)
    : cuda_pool_handle_{[valid_pool_handle]() {
        RMM_EXPECTS(nullptr != valid_pool_handle, "Unexpected null pool handle.");
        return valid_pool_handle;
      }()}
  {
    // Check if cudaMallocAsync Memory pool supported
    auto const device = rmm::detail::current_device();
    int cuda_pool_supported{};
    auto result =
      cudaDeviceGetAttribute(&cuda_pool_supported, cudaDevAttrMemoryPoolsSupported, device.value());
    RMM_EXPECTS(result == cudaSuccess && cuda_pool_supported,
                "cudaMallocAsync not supported with this CUDA driver/runtime version");
  }
#endif
 
#ifdef RMM_CUDA_MALLOC_ASYNC_SUPPORT
 
  [[nodiscard]] cudaMemPool_t pool_handle() const noexcept { return cuda_pool_handle_; }
#endif
 
  cuda_async_view_memory_resource()                                       = default;
  cuda_async_view_memory_resource(cuda_async_view_memory_resource const&) = default;
  cuda_async_view_memory_resource(cuda_async_view_memory_resource&&)      = default;
  cuda_async_view_memory_resource& operator=(cuda_async_view_memory_resource const&) = default;
  cuda_async_view_memory_resource& operator=(cuda_async_view_memory_resource&&) = default;
 
  [[nodiscard]] bool supports_streams() const noexcept override { return true; }
 
  [[nodiscard]] bool supports_get_mem_info() const noexcept override { return false; }
 
 private:
#ifdef RMM_CUDA_MALLOC_ASYNC_SUPPORT
  cudaMemPool_t cuda_pool_handle_{};
#endif
 
  void* do_allocate(std::size_t bytes, rmm::cuda_stream_view stream) override
  {
    void* ptr{nullptr};
#ifdef RMM_CUDA_MALLOC_ASYNC_SUPPORT
    if (bytes > 0) {
      RMM_CUDA_TRY_ALLOC(rmm::detail::async_alloc::cudaMallocFromPoolAsync(
        &ptr, bytes, pool_handle(), stream.value()));
    }
#else
    (void)bytes;
    (void)stream;
#endif
    return ptr;
  }
 
  void do_deallocate(void* ptr, std::size_t, rmm::cuda_stream_view stream) override
  {
#ifdef RMM_CUDA_MALLOC_ASYNC_SUPPORT
    if (ptr != nullptr) {
      RMM_ASSERT_CUDA_SUCCESS(rmm::detail::async_alloc::cudaFreeAsync(ptr, stream.value()));
    }
#else
    (void)ptr;
    (void)stream;
#endif
  }
 
  [[nodiscard]] bool do_is_equal(device_memory_resource const& other) const noexcept override
  {
    return dynamic_cast<cuda_async_view_memory_resource const*>(&other) != nullptr;
  }
 
  [[nodiscard]] std::pair<std::size_t, std::size_t> do_get_mem_info(
    rmm::cuda_stream_view) const override
  {
    return std::make_pair(0, 0);
  }
};
 
}  // namespace rmm::mr