I'm glad to hear that this has nothing to do with TBB, then?
P.S.: Are you just worried by the diagnostic (which seems harmless enough if malloc() merely postpones some administration), or are you actually getting allocation errors (you don't explicitly state what you want to do, like allocate a 2-GB block, or map a file...)? Anyway, there are probably better resources for you to consult about this problem.
P.S.: Also, use of virtual memory does not necessarily imply that storage in the swap file is used.