Fix node topology mapping (fixes #30):

- Detect CPU topology using hwloc APIs and filling in array of structs,
  where the length of the array is the total number of threads.
- Create struct to store topology information, including a toggle for
  correctly mapping a particular thread, core, and socket, to a unique
  integer. This deprecates CPU_DEV_VER.
- Create generic loop iterators for load_socket_batch, load_core_batch,
  and load_thread_batch.

Signed-off-by: Stephanie Labasan <[email protected]>

Author: Stephanie Labasan

CMakeLists.txt

@@ -4,8 +4,6 @@ cmake_minimum_required(VERSION 2.8)
 set(CMAKE_C_COMPILER "gcc")
 set(CMAKE_CXX_COMPILER "g++")
 
-set(HWLOC_DIR "" CACHE FILEPATH "path to hwloc installation")
-
 # Add -Wall if it is not there already.
 set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -g -Wall -O3")
 

include/msr_core.h

@@ -129,6 +129,21 @@ enum libmsr_batch_op_type_e
     BATCH_READ,
 };
 
+struct topo
+{
+    struct hwthread *thread_map;
+    int discontinuous_mapping;
+};
+
+struct hwthread
+{
+    int apic_id;
+    int thread_id;
+    int core_id;
+    int socket_id;
+    int sibling;
+};
+
 // Depending on their scope, MSRs can be written to or read from at either the
 // socket (aka package/cpu) or core level, and possibly the hardware thread
 // level.

src/CMake/thirdparty/SetupHwloc.cmake

@@ -1,25 +1,49 @@
-###############################################################################
-# Setup Hwloc
-# This file defines:
-#  HWLOC_FOUND - If Hwloc was found
-#  HWLOC_INCLUDE_DIRS - The Hwloc include directories
-#  
-#  If found, the Hwloc CMake targets will also be imported
-###############################################################################
-
-# first check for HWLOC_DIR
-
-if(NOT HWLOC_DIR)
-    MESSAGE(FATAL_ERROR "Hwloc support needs explicit HWLOC_DIR")
-endif()
+# First check for user-specified HWLOC_DIR
+if(HWLOC_DIR)
+    MESSAGE(STATUS "Looking for Hwloc using HWLOC_DIR = ${HWLOC_DIR}")
+
+    set(HWLOC_FOUND TRUE)
+    set(HWLOC_INCLUDE_DIRS ${HWLOC_DIR}/include)
+    set(HWLOC_LIBRARY ${HWLOC_DIR}/lib/libhwloc.so)
+
+    set(HWLOC_DIR ${HWLOC_DIR} CACHE PATH "" FORCE)
+
+    message(STATUS "FOUND Hwloc at ${HWLOC_DIR}")
+    message(STATUS "  HWLOC_INCLUDE_DIRS = ${HWLOC_INCLUDE_DIRS}")
+    message(STATUS "  HWLOC_LIBRARY = ${HWLOC_LIBRARY}")
+# If HWLOC_DIR not specified, then try to automatically find the HWLOC header
+# and library
+elseif(NOT HWLOC_DIR)
+    find_path(HWLOC_INCLUDE_DIRS
+        NAMES hwloc.h
+    )
 
-MESSAGE(STATUS "Looking for Hwloc using HWLOC_DIR = ${HWLOC_DIR}")
+    find_library(HWLOC_LIBRARY
+        NAMES libhwloc.so
+    )
 
-include(${HWLOC_DIR}/include)
+    if(HWLOC_INCLUDE_DIRS AND HWLOC_LIBRARY)
+        set(HWLOC_FOUND TRUE)
+        message(STATUS "HWLOC library found using find_library()")
+        message(STATUS "  HWLOC_INCLUDE_DIRS = ${HWLOC_INCLUDE_DIRS}")
+        message(STATUS "  HWLOC_LIBRARY = ${HWLOC_LIBRARY}")
+    endif()
+endif()
+
+# If HWLOC is still not found, then download and build HWLOC from source
+if(NOT HWLOC_INCLUDE_DIRS AND HWLOC_LIBRARY)
+    MESSAGE(STATUS "Downloading and building Hwloc from source")
 
-set(HWLOC_FOUND TRUE)
-set(HWLOC_LIBRARY ${HWLOC_DIR}/lib/libhwloc.so)
-set(HWLOC_INCLUDES ${HWLOC_DIR}/include)
+    ### Necessary for ExternalProject_Add
+    include(${CMAKE_ROOT}/Modules/ExternalProject.cmake)
+    include(../SetupExternalProjects.cmake)
+    message(STATUS "ExternalDownload Hwloc")
+    message(STATUS "  HWLOC_INCLUDE_DIRS = ${HWLOC_INCLUDE_DIRS}")
+    message(STATUS "  HWLOC_LIBRARY = ${HWLOC_LIBRARY}")
+    set(HWLOC_FOUND TRUE)
+endif()
 
-message(STATUS "FOUND Hwloc at ${HWLOC_DIR}")
-message(STATUS "HWLOC_INCLUDES = ${HWLOC_INCLUDES}")
+# Abort if all methods fail
+if(NOT HWLOC_FOUND)
+    MESSAGE(FATAL_ERROR "Hwloc support needed")
+endif()

src/CMakeLists.txt

@@ -41,4 +41,5 @@ install(TARGETS msr msr-static DESTINATION "${CMAKE_INSTALL_PREFIX}/lib" EXPORT
 #
 # Headers are in ../include
 #
-include_directories(${PROJECT_SOURCE_DIR}/include)
+include_directories(${PROJECT_SOURCE_DIR}/include
+                    ${HWLOC_INCLUDE_DIRS})