TCMalloc is a malloc replacement library optimized for multi-threaded usage. Also, it features a built-in heap debugger and profiler.
To build MariaDB 5.5 with TCMalloc, you need to use the following command
cmake -DCMAKE_EXE_LINKER_FLAGS='-ltcmalloc' -DWITH_SAFEMALLOC=OFF
Many other malloc replacement libraries (as well as heap debuggers and profilers) can be used with MariaDB in a similar fashion.