[PATCH v5 8/8] futex: Use runtime constants for __futex_hash() hot path

[Sebastian Andrzej Siewior]

On 2026-07-01 09:57:14 [+0200], Peter Zijlstra wrote:
> The big $1M question: does it actually make it go faster? The whole
> point here was performance, right? But I'm not seeing numbers showing
> how awesome these patches are.

I did complain about the about the size of __futex_data which is blown
on distro kernels due to CONFIG_NODES_SHIFT=10 on Debian for instance.
This makes it go away at no extra price but yeah let me boot a big box
and see.
If the performance remains unchanged it is still worth considering due
to size savings on the average box with 1 node. The biggest box I have
access to has four nodes. If I remember correctly, Prateek was saying
that AMD has "normal" boxes which would require =9 for normal operation
and they do run distro kernels so lowering that value is not an option.

Sebastian