Re: [PATCH] futex: fix shared futex operations on nommu

[Sebastian Andrzej Siewior]

* Rich Felker | 2016-04-26 11:53:44 [-0400]:

>The whole shared futex logic is meaningless for nommu. Perhaps I
>should have written a better message, though.
>
>With MMU, shared futex keys need to identify the physical backing for
>a memory address because it may be mapped at different addresses in
>different processes (or even multiple times in the same process).
>Without MMU this cannot happen. You only have physical addresses. So
>the "private futex" behavior of using the virtual address as the key
>is always correct (for both shared and private cases) on nommu
>systems.

So using a shared futex on NOMMU does work but it would be more
efficient to always use a private futex instead.
Is this what you are saying?

>Rich

Sebastian