pytorch

4bd9ddb0 - remove pthreadpool dependency in aten/CMake (#25894)

remove pthreadpool dependency in aten/CMake (#25894) Summary: Pull Request resolved: https://github.com/pytorch/pytorch/pull/25894 NNPack/QNNPack both depend on a third-party library "pthreadpool". There are two versions of "pthreadpool" implementation, one is the default implementation under third-party/pthreadpool, the other is caffe2 custom implementation under caffe2/utils/threadpool. Both implementations share the same interface (as defined by pthreadpool headers). Usually only one version of pthreadpool should be linked into libtorch. If QNNPACK_CUSTOM_THREADPOOL/NNPACK_CUSTOM_THREADPOOL are set to true, then QNNPack/NNPack will not link third-party/pthreadpool - they will expect the caller (libtorch) to link correct version of pthreadpool; otherwise they will bring in the default pthreadpool implementation. Looks like libtorch cmake already sets both macros to true in Dependencies.cmake and External/nnpack.cmake. And currently libtorch mobile build includes the caffe2/utils/threadpool pthreadpool implementation. So it shouldn't try to explicitly link default pthreadpool target in aten/CMake in this AT_NNPACK_ENABLED section. Test Plan: - Before this diff, libtorch.so links libpthreadpool.a: ``` LINK_LIBRARIES = lib/libc10.so lib/libqnnpack.a lib/libnnpack.a lib/libcpuinfo.a -llog -ldl -lm lib/libnnpack.a lib/libpthreadpool.a lib/libcpuinfo.a lib/libclog.a -llog -latomic -lm ``` - After this diff, libtorch.so no longer links libpthreadpool.a: ``` LINK_LIBRARIES = lib/libc10.so lib/libqnnpack.a lib/libnnpack.a lib/libcpuinfo.a -llog -ldl -lm lib/libnnpack.a lib/libcpuinfo.a lib/libclog.a -llog -latomic -lm ``` - Tried the following combinations to make sure things work as expected: * remove caffe2/utils/threadpool, remove libpthreadpool: link error; * keep caffe2/utils/threadpool, remove libpthreadpool: no link error; * remove caffe2/utils/threadpool, add back libpthreadpool: no link error; Pull Request resolved: https://github.com/pytorch/pytorch/pull/25894 Reviewed By: dreiss Differential Revision: D17279723 Pulled By: ljk53 fbshipit-source-id: ae5aa7ca7283a276ecf1e2140bad0a6af3efdb3a