Messages in this thread | | | Date | Tue, 26 Apr 2016 18:11:07 +0200 | From | Sebastian Andrzej Siewior <> | Subject | Re: [PATCH] futex: fix shared futex operations on nommu |
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* 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
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