Re: [RFC-PATCH 2/4] mm: Add __rcu_alloc_page_lockless() func.

Peter Zijlstra
2020-09-24T11:19:17Z

On Thu, Sep 24, 2020 at 10:16:14AM +0200, Uladzislau Rezki wrote:
> The key point is "enough". We need pages to make a) fast progress b) support
> single argument of kvfree_rcu(one_arg). Not vice versa. That "enough" depends
> on scheduler latency and vague pre-allocated number of pages, it might
> be not enough what would require to refill it more and more or we can overshoot
> that would lead to memory overhead. So we have here timing issues and
> not accurate model. IMHO.

I'm firmly opposed to the single argument kvfree_rcu() idea, that's
requiring memory to free memory.