disable GINKGO_BUILD_HWLOC by default

CMakeLists.txt

@@ -78,11 +78,7 @@ option(GINKGO_SPLIT_TEMPLATE_INSTANTIATIONS "Split template instantiations for s
 mark_as_advanced(GINKGO_SPLIT_TEMPLATE_INSTANTIATIONS)
 option(GINKGO_JACOBI_FULL_OPTIMIZATIONS "Use all the optimizations for the CUDA Jacobi algorithm" OFF)
 option(BUILD_SHARED_LIBS "Build shared (.so, .dylib, .dll) libraries" ON)
-if(MSVC OR WIN32 OR CYGWIN OR APPLE)
-    option(GINKGO_BUILD_HWLOC "Build Ginkgo with HWLOC. Default is OFF. Ginkgo does not support HWLOC on Windows/MacOS" OFF)
-else()
-    option(GINKGO_BUILD_HWLOC "Build Ginkgo with HWLOC. Enabled if a system installation is found." ${HWLOC_FOUND})
-endif()
+option(GINKGO_BUILD_HWLOC "Build Ginkgo with HWLOC. Default is OFF." OFF)
 option(GINKGO_BUILD_PAPI_SDE "Build Ginkgo with PAPI SDE. Enabled if a system installation is found." ${PAPI_SDE_FOUND})
 option(GINKGO_DPCPP_SINGLE_MODE "Do not compile double kernels for the DPC++ backend." OFF)
 option(GINKGO_INSTALL_RPATH "Set the RPATH when installing its libraries." ON)
@@ -275,13 +271,9 @@ endif()
 # System provided, third party libraries (not bundled!)
 set(GINKGO_HAVE_HWLOC 0)
 if(GINKGO_BUILD_HWLOC)
-    find_package(HWLOC 2.1)
-    if (HWLOC_FOUND)
-        set(GINKGO_HAVE_HWLOC 1)
-    else()
-        message(WARNING "HWLOC could not be found. HWLOC support will be disabled.")
-        set(GINKGO_BUILD_HWLOC OFF CACHE BOOL "HWLOC support was disabled because a system package could not be found." FORCE)
-    endif()
+    find_package(HWLOC 2.1 REQUIRED)
+    set(GINKGO_HAVE_HWLOC 1)
+    message(WARNING "The GINKGO_BUILD_HWLOC option has no beneficial effect. Consider setting it to GINKGO_BUILD_HWLOC=OFF.")
 endif()
 
 set(GINKGO_HAVE_PAPI_SDE 0)

INSTALL.md

@@ -51,9 +51,7 @@ Ginkgo adds the following additional switches to control what is being built:
     `OFF` otherwise.
 *   `-DGINKGO_HIP_AMDGPU="gpuarch1;gpuarch2"` the amdgpu_target(s) variable
     passed to hipcc for the `hcc` HIP backend. The default is none (auto).
-*   `-DGINKGO_BUILD_HWLOC={ON, OFF}` builds Ginkgo with HWLOC. If system HWLOC
-    is not found, Ginkgo will try to build it. Default is `ON` on Linux. Ginkgo
-    does not support HWLOC on Windows/MacOS, so the default is `OFF` on Windows/MacOS.
+*   `-DGINKGO_BUILD_HWLOC={ON, OFF}` builds Ginkgo with HWLOC. Default is `OFF`.
 *   `-DGINKGO_BUILD_DOC={ON, OFF}` creates an HTML version of Ginkgo's documentation
     from inline comments in the code. The default is `OFF`.
 *   `-DGINKGO_DOC_GENERATE_EXAMPLES={ON, OFF}` generates the documentation of examples

cmake/Modules/FindHWLOC.cmake

@@ -67,15 +67,20 @@ if (HWLOC_INCLUDE_DIRS)
     endif()
 endif()
 
-if (NOT HWLOC_FIND_QUIETLY)
-    if (HWLOC_INCLUDE_DIRS AND HWLOC_LIBRARIES)
-        message(STATUS "Looking for HWLOC - found version ${HWLOC_VERSION}")
-    else()
-        message(STATUS "${Magenta}Looking for HWLOC - not found"
-            "\n   Please check that your environment variable HWLOC_DIR"
-            "\n   has been set properly.${ColourReset}")
-        unset(HWLOC_LIBRARIES CACHE)
-        unset(HWLOC_INCLUDE_DIRS CACHE)
+if (HWLOC_INCLUDE_DIRS AND HWLOC_LIBRARIES)
+    if (NOT HWLOC_FIND_QUIETLY)
+    message(STATUS "Looking for HWLOC - found version ${HWLOC_VERSION}")
+    endif()
+else()
+    unset(HWLOC_LIBRARIES CACHE)
+    unset(HWLOC_INCLUDE_DIRS CACHE)
+    set(hwloc_err_msg "${Magenta}Looking for HWLOC - not found
+Please check that your environment variable HWLOC_DIR has been set properly.${ColourReset}")
+    if(HWLOC_FIND_REQUIRED)
+        message(FATAL_ERROR "${hwloc_err_msg}")
+    endif()
+    if(NOT HWLOC_FIND_QUIETLY)
+        message(STATUS "${hwloc_err_msg}")
     endif()
 endif()
 

cmake/autodetect_system_libs.cmake

@@ -1,7 +1,3 @@
-if (NOT DEFINED GINKGO_BUILD_HWLOC)
-    find_package(HWLOC 2.1)
-endif()
-
 if (NOT DEFINED GINKGO_BUILD_PAPI_SDE)
     find_package(PAPI 7.0.1.0 COMPONENTS sde)
 endif()

cuda/test/base/CMakeLists.txt

@@ -2,8 +2,12 @@ ginkgo_create_test(array EXECUTABLE_NAME array_test RESOURCE_TYPE cudagpu) # arr
 ginkgo_create_cuda_test(cuda_executor)
 ginkgo_create_test(index_set RESOURCE_TYPE cudagpu)
 if(GINKGO_HAVE_HWLOC)
-    find_package(NUMA REQUIRED)
-    ginkgo_create_cuda_test(cuda_executor_topology ADDITIONAL_LIBRARIES NUMA::NUMA)
+    find_package(NUMA)
+    if(NUMA_FOUND)
+        ginkgo_create_cuda_test(cuda_executor_topology ADDITIONAL_LIBRARIES NUMA::NUMA)
+    else()
+        message(STATUS "NUMA not found, disabling HWLOC test.")
+    endif()
 endif()
 ginkgo_create_cuda_test(exception_helpers)
 ginkgo_create_cuda_test(kernel_launch)

hip/test/base/CMakeLists.txt

@@ -1,8 +1,12 @@
 ginkgo_create_hip_test(hip_executor)
 ginkgo_create_test(index_set RESOURCE_TYPE hipgpu)
 if(GINKGO_HAVE_HWLOC)
-    find_package(NUMA REQUIRED)
-    ginkgo_create_hip_test(hip_executor_topology ADDITIONAL_LIBRARIES NUMA::NUMA)
+    find_package(NUMA)
+    if(NUMA_FOUND)
+        ginkgo_create_hip_test(hip_executor_topology ADDITIONAL_LIBRARIES NUMA::NUMA)
+    else()
+        message(STATUS "NUMA not found, disabling HWLOC test.")
+    endif()
 endif()
 ginkgo_create_hip_test(kernel_launch)
 # correct flags for kernel_launch.hpp are set in GINKGO_HIPCC_OPTIONS