Re: [RFC PATCH 2/3] futex: Add basic infrastructure for local task local hash.

From: Sebastian Andrzej Siewior
Date: Mon Oct 28 2024 - 06:24:22 EST


On 2024-10-28 11:16:33 [+0100], Peter Zijlstra wrote:
> On Sun, Oct 27, 2024 at 12:34:51AM +0200, Sebastian Andrzej Siewior wrote:
>
> > Introduce a task local hash map. The hashmap can be allocated via
> > prctl(PR_FUTEX_HASH, PR_FUTEX_HASH_ALLOCATE, 0)
>
> Per process, per task is useless and will make things malfunction.
>
> Things missing in this patch are CLONE_THREAD / CLONE_VM, and create
> must be absolutely forbidden once mm_users != 1.

I moved this to struct signal_struct and limited it for now to the
group leader.

Sebastian