Merge branch 'fea-explicit-initial-pool-size' into fea-host-pinned-mr

benchmarks/device_uvector/device_uvector_bench.cu

@@ -40,7 +40,7 @@ void BM_UvectorSizeConstruction(benchmark::State& state)
 {
   rmm::mr::cuda_memory_resource cuda_mr{};
   rmm::mr::pool_memory_resource<rmm::mr::cuda_memory_resource> mr{
-    &cuda_mr, rmm::percent_of_free_device_memory(1. / 2)};
+    &cuda_mr, rmm::percent_of_free_device_memory(50)};
   rmm::mr::set_current_device_resource(&mr);
 
   for (auto _ : state) {  // NOLINT(clang-analyzer-deadcode.DeadStores)

include/rmm/cuda_device.hpp

@@ -131,8 +131,9 @@ const auto available_device_memory = rmm::available_device_memory;
 }  // namespace detail
 
 /**
- * @brief Returns the approximate specified percent of free device memory on the current CUDA
- * device, aligned to the nearest CUDA allocation size.
+ * @brief Returns the approximate specified percent of total device memory on the current CUDA
+ * device or the total free device memory (whichever is smaller), aligned to the nearest CUDA
+ * allocation size.
  *
  * @param percent The percent of free memory to return. Defaults to 50%.
  *
@@ -142,7 +143,7 @@ inline std::size_t percent_of_free_device_memory(int percent = 50)
 {
   auto const [free, total] = rmm::available_device_memory();
 
-  double fraction = static_cast<double>(percent) / 100;
+  double const fraction = static_cast<double>(percent) / 100.0;
 
   return rmm::detail::align_up(
     std::min(free, static_cast<std::size_t>(static_cast<double>(total) * fraction)),

include/rmm/mr/device/pool_memory_resource.hpp

@@ -113,6 +113,8 @@ class pool_memory_resource final
    * @brief [DEPRECATED] Construct a `pool_memory_resource` and allocate the initial device memory
    * pool using `upstream_mr`.
    *
+   * @deprecated Use the constructor that takes an explicit initial pool size instead.
+   *
    * @throws rmm::logic_error if `upstream_mr == nullptr`
    * @throws rmm::logic_error if `initial_pool_size` is neither the default nor aligned to a
    * multiple of pool_memory_resource::allocation_alignment bytes.
@@ -136,6 +138,8 @@ class pool_memory_resource final
    * @brief Construct a `pool_memory_resource` and allocate the initial device memory pool using
    * `upstream_mr`.
    *
+   * @deprecated Use the constructor that takes an explicit initial size instead.
+   *
    * @throws rmm::logic_error if `upstream_mr == nullptr`
    * @throws rmm::logic_error if `initial_pool_size` is neither the default nor aligned to a
    * multiple of pool_memory_resource::allocation_alignment bytes.
@@ -320,16 +324,11 @@ class pool_memory_resource final
   /**
    * @brief Allocate initial memory for the pool
    *
-   * If initial_size is unset, then queries the upstream memory resource for available memory if
-   * upstream supports `get_mem_info`, or queries the device (using CUDA API) for available memory
-   * if not. Then attempts to initialize to half the available memory.
-   *
-   * If initial_size is set, then tries to initialize the pool to that size.
-   *
    * @param initial_size The optional initial size for the pool
    * @param maximum_size The optional maximum size for the pool
+   *
+   * @throws logic_error if @p initial_size is larger than @p maximum_size (if set).
    */
-  // NOLINTNEXTLINE(bugprone-easily-swappable-parameters)
   void initialize_pool(std::size_t initial_size, thrust::optional<std::size_t> maximum_size)
   {
     current_pool_size_ = 0;  // try_to_expand will set this if it succeeds