Re: [PATCH v2] locking/rwbase: Prevent indefinite writer starvation

[Sebastian Andrzej Siewior]

On 2023-01-20 17:37:11 [+0800], Hillf Danton wrote:
> 
> I am fine with either 4ms or 40ms, or a second.
> 
> Given the cure, does it still work when reader bias for RT tasks is allowed?
No.

> If not, why keep starving waiters after they pay the 40ms price?

That kind of starvation will also happen if you have only spinlock_t
locks and you say 3 RT tasks that acquire the lock back to back. And a
few SCHED_OTHER tasks. Those 3 will be always be in front of the queue
(as they skip the line) and the following SCHED_OTHER tasks will starve
and never get the lock.

So it is basically the same scenario.

Sebastian