umem should support posix_memalign()
Libumem is described as being a replacement for the standard malloc functions. Illumos supports posix_memalign() in its standard C library. If libumem is used as a substitute to provide the standard allocation functions (at link time or run-time) and the application is using posix_memalign(), there will be a mix of allocator functions used (e.g. free() from umem used on pointer allocated by standard C library posix_memalign()) and the application is likely to fail. The solution for this is for libumem to also support posix_memalign().
Libumem already provides memalign().