fix openmp affinity abort when cpu goes offline (#4370)

Tencent · Nov 26, 2022 · c934c6e · c934c6e
1 parent bdcbc37
commit c934c6e
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Showing 3 changed files with 22 additions and 7 deletions.
diff --git a/cmake/ncnnConfig.cmake.in b/cmake/ncnnConfig.cmake.in
@@ -20,10 +20,7 @@ if(NCNN_VULKAN)
  if(NOT NCNN_SHARED_LIB)
  if(NCNN_SYSTEM_GLSLANG)
  find_package(glslang QUIET)
- if(glslang_FOUND)
- add_library(glslang ALIAS glslang::glslang)
- add_library(SPIRV ALIAS glslang::SPIRV)
- else()
+ if(NOT glslang_FOUND)
  set(GLSLANG_TARGET_DIR "@GLSLANG_TARGET_DIR@")
  include(${GLSLANG_TARGET_DIR}/OSDependentTargets.cmake)
  include(${GLSLANG_TARGET_DIR}/OGLCompilerTargets.cmake)
@@ -37,8 +34,6 @@ if(NCNN_VULKAN)
  else()
  set(glslang_DIR "${CMAKE_CURRENT_LIST_DIR}/../../../@CMAKE_INSTALL_LIBDIR@/cmake/glslang")
  find_package(glslang QUIET)
- add_library(glslang ALIAS glslang::glslang)
- add_library(SPIRV ALIAS glslang::SPIRV)
  endif()
 
  endif()

diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
@@ -226,6 +226,8 @@ if(NCNN_OPENMP)
  elseif(ANDROID_NDK_MAJOR AND (ANDROID_NDK_MAJOR GREATER 20))
  target_compile_options(ncnn PRIVATE -fopenmp)
  target_link_libraries(ncnn PUBLIC -fopenmp -static-openmp)
+ # see cpu.cpp __wrap___kmp_abort_process comment for the linker magic
+ target_link_libraries(ncnn PUBLIC -Wl,-wrap,__kmp_affinity_determine_capable)
  elseif(OpenMP_CXX_FOUND)
  target_link_libraries(ncnn PUBLIC OpenMP::OpenMP_CXX)
  else()

diff --git a/src/cpu.cpp b/src/cpu.cpp
@@ -1704,7 +1704,7 @@ static int setup_thread_affinity_masks()
  {
  int max_freq_khz = get_max_freq_khz(i);
 
- //  NCNN_LOGE("%d max freq = %d khz", i, max_freq_khz);
+ // NCNN_LOGE("%d max freq = %d khz", i, max_freq_khz);
 
  cpu_max_freq_khz[i] = max_freq_khz;
 
@@ -2041,3 +2041,21 @@ int set_flush_denormals(int flush_denormals)
 }
 
 } // namespace ncnn
+
+#if defined __ANDROID__ && defined(_OPENMP) && __clang__
+#ifdef __cplusplus
+extern "C" {
+#endif
+void __wrap___kmp_affinity_determine_capable(const char* /*env_var*/)
+{
+ // the internal affinity routines in llvm openmp call abort on __NR_sched_getaffinity / __NR_sched_setaffinity fails
+ // ref KMPNativeAffinity::get_system_affinity/set_system_affinity in openmp/runtime/src/kmp_affinity.h
+ // and cpu core goes offline in powersave mode on android, which triggers abort
+ // ATM there is no known api for controlling the abort behavior
+ // override __kmp_affinity_determine_capable with empty body to disable affinity regardless of KMP_AFFINITY env_var
+ // ugly hack works >.< --- nihui
+}
+#ifdef __cplusplus
+} // extern "C"
+#endif
+#endif