diff --git a/paddle/memory/README.md b/paddle/memory/README.md index 24af37987e05761d9d6866e759ae0e4483ac570c..b71ca29696513203f75b5a72dff6bd1bf963e726 100644 --- a/paddle/memory/README.md +++ b/paddle/memory/README.md @@ -25,14 +25,16 @@ cout << memory::Used(pl); memory::Free(pl, p); ``` -### The API +### API In `paddle/memory/memory.h` we have: ```cpp -template <typeanme Place> void* Alloc(Place, size_t); -template <typeanme Place> void Free(Place, void*); -} +namespace memory { +template <typename Place> void* Alloc(Place, size_t); +template <typename Place> void Free(Place, void*); +template <typename Place> void Used(Place); +} // namespace memory ``` These function templates have specializations on either `platform::CPUPlace` or `platform::GPUPlace`: @@ -48,12 +50,14 @@ and ```cpp template<> -void Alloc(GPUPlace)(GPUPlace p, size_t size) { +void Alloc<GPUPlace>(GPUPlace p, size_t size) { return GetGPUBuddyAllocator(p.id)->Alloc(size); } ``` -### The Implementation +Similar specializations exist for `Free` and `Used`. + +### Implementation `GetCPUBuddyAllocator` and `GetGPUBuddyAllocator` are singletions. @@ -94,7 +98,7 @@ class BuddyAllocator { private: struct Block { size_t size; - Blobk* left, right; + Block* left, right; }; ... }; @@ -102,15 +106,15 @@ class BuddyAllocator { #### System Allocators -The `GPUAllocator` and `CPUAllocator` are calls *system allocators*. They hold information about the device, including the amount of memory has been allocated. So that we can call +The `GPUAllocator` and `CPUAllocator` are calls *system allocators*. They work as the fallback allocators of `BuddyAllocator`. A system allocator holds information about a device, including the amount of memory has been allocated, so we can call -- `GPUAllocator::Used` and -- `CPUAllocator::Used` +- `GPUAllocator::Used()` and +- `CPUAllocator::Used()` to get the amount of memory that has been allocated so far. -## Why Such a Design +## Justification I got inspiration from Majel and Caffe2, though above design look different from both.