Comment (by Roland Haas):

There's an implementation in branch rhaas/short_walltime of CactusUtils. Turns out Cactus already checks if malloc.h (though not explicitly for malloc_info or open_memstream) exists. I would be extremely surprised if this worked with tcmalloc or jemalloc. It also restrict is restricted to Linux, at least on OSX, even when compiling with gcc there is no malloc.h, though given that all clusters are running GNU/Linux these days I am not too worried about that.

The branch produces numbers identical to mallinfo’s uordblks for the test function in embedded in it (for informational purposes only).

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Ticket URL: https://bitbucket.org/einsteintoolkit/tickets/issues/2352/support-64-bit-numbers-for