Dep/Jemalloc: Enable MADV_FREE if available

(cherry picked from commit 10ad43916f)

.travis.yml

@@ -39,7 +39,7 @@ install:
   - mysql -uroot -e 'create database test_mysql;'
   - mkdir bin
   - cd bin
-  - cmake ../ -DWITH_WARNINGS=1 -DWITH_COREDEBUG=0 -DUSE_COREPCH=1 -DUSE_SCRIPTPCH=1 -DTOOLS=1 -DSCRIPTS=dynamic -DSERVERS=1 -DNOJEM=1 -DCMAKE_BUILD_TYPE=Debug -DCMAKE_C_FLAGS="-Werror" -DCMAKE_CXX_FLAGS="-Werror" -DCMAKE_C_FLAGS_DEBUG="-DNDEBUG" -DCMAKE_CXX_FLAGS_DEBUG="-DNDEBUG" -DCMAKE_INSTALL_PREFIX=check_install
+  - cmake ../ -DWITH_WARNINGS=1 -DWITH_COREDEBUG=0 -DUSE_COREPCH=1 -DUSE_SCRIPTPCH=1 -DTOOLS=1 -DSCRIPTS=dynamic -DSERVERS=1 -DNOJEM=0 -DCMAKE_BUILD_TYPE=Debug -DCMAKE_C_FLAGS="-Werror" -DCMAKE_CXX_FLAGS="-Werror" -DCMAKE_C_FLAGS_DEBUG="-DNDEBUG" -DCMAKE_CXX_FLAGS_DEBUG="-DNDEBUG" -DCMAKE_INSTALL_PREFIX=check_install
   - cd ..
   - chmod +x contrib/check_updates.sh
 

dep/jemalloc/CMakeLists.txt

@@ -10,6 +10,8 @@
 
 if(CMAKE_SYSTEM_NAME MATCHES "Linux" AND NOT NOJEM)
   # We need to generate the jemalloc_def.h header based on platform-specific settings
+  CHECK_SYMBOL_EXISTS(MADV_FREE "sys/mman.h" HAVE_MADV_FREE)
+  
   if (PLATFORM EQUAL 32)
     set(JEM_SIZEDEF 2)
     set(JEM_TLSMODEL)
@@ -20,6 +22,12 @@ if(CMAKE_SYSTEM_NAME MATCHES "Linux" AND NOT NOJEM)
 	set(JEM_VADDRBITS 48)
   endif()
 
+  if (HAVE_MADV_FREE)
+    set(JEM_MADFREE_DEF "#define")
+  else()
+    set(JEM_MADFREE_DEF "#undef")
+  endif()
+
   # Create the header, so we can use it
   configure_file(
     "${CMAKE_SOURCE_DIR}/dep/jemalloc/jemalloc_internal_defs.h.in.cmake"

dep/jemalloc/jemalloc_internal_defs.h.in.cmake

@@ -268,7 +268,7 @@
  *                                 MADV_FREE, though typically with higher
  *                                 system overhead.
  */
-/*#define JEMALLOC_PURGE_MADVISE_FREE*/ 
+@JEM_MADFREE_DEF@ JEMALLOC_PURGE_MADVISE_FREE
 #define JEMALLOC_PURGE_MADVISE_DONTNEED 
 #define JEMALLOC_PURGE_MADVISE_DONTNEED_ZEROS 1