I tried using tbbmalloc_proxy on OSX Yosemite on a QT application and I got an instant crash during start up.
It crashes within __TBB_malloc_free_definite_size(), which I think is because it's being given a pointer that wasn't allocated using tbbmalloc to begin with. Looking in tbbmalloc/proxy_overload_osx.h, impl_free_definite_size() directly calls __TBB_malloc_free_definite_size() which has no checks for foreign allocated pointers. This looks fishy to me because impl_free(), declared as PREFIX(free) in tbbmalloc/proxy.cpp, calls __TBB_malloc_safer_free() which does have checks for foreign pointers. So there appears to be a bug here?
