commit bb3c3cbee65ef42b2b3048afae008c719bc2056a
Author: Ole Reifschneider <mail@ole-reifschneider.de>
Date:   Sat Oct 24 18:48:01 2015 +0200

    Make jemalloc optional
    
    Don't enable it automagically if it exists

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 348e138..53e3873 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -260,12 +260,16 @@ if((CLANG_ASAN_UBSAN OR CLANG_MSAN OR CLANG_TSAN) AND NOT CMAKE_C_COMPILER_ID MA
   message(FATAL_ERROR "Sanitizers are only supported for Clang.")
 endif()
 
-if(CLANG_ASAN_UBSAN OR CLANG_MSAN OR CLANG_TSAN)
-  message(STATUS "Sanitizers have been enabled; don't use jemalloc.")
-else()
-  find_package(JeMalloc)
-  if(JEMALLOC_FOUND)
-    include_directories(SYSTEM ${JEMALLOC_INCLUDE_DIRS})
+option(ENABLE_JEMALLOC "enable jemalloc" OFF)
+
+if (ENABLE_JEMALLOC)
+  if(CLANG_ASAN_UBSAN OR CLANG_MSAN OR CLANG_TSAN)
+    message(STATUS "Sanitizers have been enabled; don't use jemalloc.")
+  else()
+    find_package(JeMalloc)
+    if(JEMALLOC_FOUND)
+      include_directories(SYSTEM ${JEMALLOC_INCLUDE_DIRS})
+    endif()
   endif()
 endif()