Re: [PATCH v12 00/21] futex: Add support task local hash maps, FUTEX2_NUMA and FUTEX2_MPOL

[Sebastian Andrzej Siewior]

On 2025-05-06 09:36:11 [+0200], Peter Zijlstra wrote:
> Well, if you do stupid things, you get to keep the pieces or something
> along those lines. Same as when userspace goes scribble the node value
> while another thread is waiting and all that.
> 
> Even with the unconditional write back you're going to have a problem
> with concurrent wait on the same futex.

We could add a global lock for the write back case to ensure there is
only one at a time. However let me document the current behaviour of the
new pieces and tick it off ;)

Sebastian