Re: [PATC] block: update queue limits atomically

[Mikulas Patocka]

On Tue, 18 Mar 2025, Jens Axboe wrote:

> > Yeah, it looks fine, but I feel it is still fragile, and not sure it is one
> > accepted solution.
> 
> Agree - it'd be much better to have the bio drivers provide the same
> guarantees that we get on the request side, rather than play games with
> this and pretend that concurrent update and usage is fine.
> 
> -- 
> Jens Axboe

And what mechanism should they use to read the queue limits?
* locking? (would degrade performance)
* percpu-rwsem? (no overhead for readers, writers wait for the RCU 
  synchronization)
* RCU?
* anything else?

Mikulas