Re: [PATCH v9 00/11] futex: Add support task local hash maps.

[Sebastian Andrzej Siewior <bigeasy@linutronix.de>]

On 2025-03-03 15:17:55 [+0100], To Peter Zijlstra wrote:
> > Anyway, the entire stack builds and boots, but is otherwise very much
> > untested.
> > 
> > WDYT?
> 
> well. Let take a look and do a bit of hammering.

so you kept the q.drop_hb_ref logic and the reference get. You kept the
private reference but renamed it and hid it behind the CLASS. I meant to
do it, just wanted to check if you had another idea regarding it. But
okay.

You avoided the two states by dropping refcount only there is no !new
pointer. That should work. 

There is no refcount check in futex_hash_free(). It wouldn't hurt to
check futex_phash for 0/1, right?

My first few tests succeeded. And I have a few RCU annotations, which I
post once I complete them and finish my requeue-pi tests.

Sebastian