Subject: Re: [bpf-next V5 PATCH 11/15] page_pool: refurbish version of page_pool code

From: Jesper Dangaard Brouer <[email-masked]>
Date: Fri, 23 Mar 2018 15:15:22 +0100

On Fri, 23 Mar 2018 06:29:55 -0700
Eric Dumazet <[email-masked]> wrote:

> On 03/23/2018 05:18 AM, Jesper Dangaard Brouer wrote:
> 
> > +
> > +void page_pool_destroy_rcu(struct page_pool *pool)
> > +{
> > +	call_rcu(&pool->rcu, __page_pool_destroy_rcu);
> > +}
> > +EXPORT_SYMBOL(page_pool_destroy_rcu);
> >   
> 
> 
> Why do we need to respect one rcu grace period before destroying a page pool ?

Due to previous allocator ID patch, which can have a pointer reference
to a page_pool, and the allocator ID lookup uses RCU.

> In any case, this should be called page_pool_destroy()

Okay.

-- 
Best regards,
  Jesper Dangaard Brouer
  MSc.CS, Principal Kernel Engineer at Red Hat
  LinkedIn: http://www.linkedin.com/in/brouer