Re: [RFC PATCH v3 3/4] hazptr: Implement Hazard Pointers

[Mathieu Desnoyers]

On 2024-10-08 15:50, Mathieu Desnoyers wrote:
[...]

> +/* Retire the protected hazard pointer from @slot. */
> +static inline
> +void hazptr_retire(struct hazptr_slot *slot, void *addr)
> +{
> +	WARN_ON_ONCE(slot->addr != addr);
> +	smp_store_release(&slot->addr, NULL);
> +}

Actually, comparing this with the literature and past presentations
from Maged Michael, "retire" is not the appropriate name here.

With Hazard Pointers, AFAIU, the "retire" operation is similar to a
call_rcu() memory reclaim. It marks the object for eventual reclamation
when it is safe to do so.

The API here really just releases the recently protected hazard
pointer. So I will rename this to "hazptr_release()".

At this stage, this hazptr API does not implement any retire operation,
and only offers the hazptr_scan() for reader/updater synchronization,
leaving the actual reclaim to the caller.

Thanks,

Mathieu

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