Good point.
PyLong_FromLong() is faster than PyLong_FromLongLong(), IMO the fastest should be used when it is possible.
PyLong_FromUnsignedLong() and PyLong_FromUnsignedLongLong() are almost identical, they implement the same algorithm. The first one uses unsigned long (on the stack and for a register) while the other uses unsigned long long, so the difference in performance may be in the order of nano seconds on current processors. Should only PyLong_FromUnsignedLongLong() be used then or should this be left as is for consistency with the handling of PyLong_FromLong() ?

Another point (not related) is that the d_ino member of the DirEntry structure is of type ino_t which is unsigned and PR 1666 should be corrected to use unsigned instead in the last modifications made by the PR in os_DirEntry_inode_impl(). I will push this change when a decision has been taken on the point raised by Martin.