ARROW-2215: [Plasma] Hugetables munmap issue

[pcmoritz]

No description provided.

[xhochy]

Please don't do sudo calls in unit tests. This could rather be a script that is run as an extra step in the CI. Still, this does not seem to test any Arrow/Plasma functionality?

[robertnishihara]

The filesystem created here is used to test Plasma support for huge pages, which is a performance optimization.

[pcmoritz]

Thanks for the tip about sudo. The test was not complete yet. It is now ready, the test failure is unrelated.

[robertnishihara]

Looks good to me. Consider adding a comment in malloc.cc that if we change

arrow/cpp/src/plasma/malloc.cc

Line 158 in e50a8ec

pointer = pointer_advance(pointer, sizeof(size_t));

then we need to modify the client as well.

[robertnishihara]

I believe @xhochy's comment is addressed, so I will attempt to merge this.