Re: [patch] v2 mm/slub: restore/expand unfreeze_partials() local exclusion scope

[Mike Galbraith]

It's moot, but for the record...

@@ -2418,6 +2418,17 @@ static void __unfreeze_partials(struct k
>  	if (n)
>  		spin_unlock_irqrestore(&n->list_lock, flags);
>
> +	/*
> +	 * If we got here via __slab_free() -> put_cpu_partial(),
> +	 * memcg_free_page_obj_cgroups() ->kfree() may send us
> +	 * back to __slab_free() -> put_cpu_partial() for an
> +	 * unfortunate second encounter with cpu_slab->lock.
> +	 */
> +	if (IS_ENABLED(CONFIG_PREEMPT_RT) && memcg_kmem_enabled()) {
> +		lockdep_assert_held(this_cpu_ptr(&s->cpu_slab.lock.lock));

...that assert needs to hide behind something less transparent.

	-Mike