Suppress std::hardware_destructive_interference_size warning on GCC 13+ (#166297)

# Motivation
In https://github.com/pytorch/pytorch/pull/145591, `std::hardware_destructive_interference_size` was introduced in CUDACachingAllocator. Later, https://github.com/pytorch/pytorch/pull/160067 moved it to `c10/core/alignment.h` for code reuse.
However, on **GCC 13+** using `std::hardware_destructive_interference_size` triggers the following warning:
```bash
warning: use of ‘std::hardware_destructive_interference_size’ [-Winterference-size]
/home/pt-gpu/4T-4652/guangyey/stock-pytorch/aten/src/ATen/core/CachingHostAllocator.h:42:16: note: its value can vary between compiler versions or with different ‘-mtune’ or ‘-mcpu’ flags
/home/pt-gpu/4T-4652/guangyey/stock-pytorch/aten/src/ATen/core/CachingHostAllocator.h:42:16: note: if this use is part of a public ABI, change it to instead use a constant variable you define
/home/pt-gpu/4T-4652/guangyey/stock-pytorch/aten/src/ATen/core/CachingHostAllocator.h:42:16: note: the default value for the current CPU tuning is 64 bytes
/home/pt-gpu/4T-4652/guangyey/stock-pytorch/aten/src/ATen/core/CachingHostAllocator.h:42:16: note: you can stabilize this value with ‘--param hardware_destructive_interference_size=64’, or disable this warning with ‘-Wno-interference-size’
```

# Solution
- Solution 1: Replace `c10::hardware_destructive_interference_size` with a constant 64.
```cpp
constexpr std::size_t hardware_destructive_interference_size = 64;
```

- Solution 2: adding `-Wno-interference-size’ to 8d4e48831e/cmake/public/utils.cmake (L386) to suppress the warning.

# Additional Context
The current implementation uses the second approach. If the reviewers prefer the first approach, I am happy to update it accordingly.

Pull Request resolved: https://github.com/pytorch/pytorch/pull/166297
Approved by: https://github.com/ezyang
This commit is contained in:
Yu, Guangye 2025-10-27 18:08:18 +00:00 committed by PyTorch MergeBot
parent c201a1cab1
commit c9eabadc5e
2 changed files with 3 additions and 3 deletions

View File

@ -677,8 +677,8 @@ struct CachingHostAllocatorImpl {
// size. This allows us to quickly find a free block of the right size.
// We use deque to store per size free list and guard the list with its own
// mutex.
alignas(hardware_destructive_interference_size) std::vector<FreeBlockList<B>> free_list_ =
std::vector<FreeBlockList<B>>(MAX_SIZE_INDEX);
alignas(hardware_destructive_interference_size) std::vector<FreeBlockList<B>>
free_list_{MAX_SIZE_INDEX};
alignas(hardware_destructive_interference_size) std::mutex events_mutex_;
std::deque<std::pair<E, B*>> events_; // event queue paired with block

View File

@ -383,7 +383,7 @@ function(torch_compile_options libname)
-Wno-strict-aliasing
)
if(CMAKE_CXX_COMPILER_ID STREQUAL "GNU")
list(APPEND private_compile_options -Wredundant-move)
list(APPEND private_compile_options -Wredundant-move -Wno-interference-size)
endif()
if(CMAKE_CXX_COMPILER_ID MATCHES "Clang")
list(APPEND private_compile_options -Wextra-semi -Wmove)