Re: [patch 4/8] futex: Add support for unlocking robust futexes

[Mathieu Desnoyers]

On 2026-03-16 13:13, Thomas Gleixner wrote:
[...]
> PI futexes have a similar problem both for the non-contented user space
> unlock and the in kernel unlock:
>
>    1)	robust_list_set_op_pending(mutex);
>    2)	robust_list_remove(mutex);
> 	
>    	lval = gettid();
>    3)	if (!atomic_try_cmpxchg(lock, lval, 0))
>    4)		sys_futex(UNLOCK_PI,....);
>    5)	robust_list_clear_op_pending();

We can document that the window in this case is between #3 and #5.

Other than this detail:

Reviewed-by: Mathieu Desnoyers <mathieu.desnoyers@xxxxxxxxxxxx>

--
Mathieu Desnoyers
EfficiOS Inc.
https://www.efficios.com