Re: [PATCH net] page_pool: fix inconsistency for page_pool_ring_[un]lock()

Ilias Apalodimas
2023-05-22T11:46:06Z

Thanks Yunsheng

On Mon, 22 May 2023 at 14:08, Jesper Dangaard Brouer <jbrouer@redhat.com> wrote:
>
>
>
> On 22/05/2023 05.17, Yunsheng Lin wrote:
> > page_pool_ring_[un]lock() use in_softirq() to decide which
> > spin lock variant to use, and when they are called in the
> > context with in_softirq() being false, spin_lock_bh() is
> > called in page_pool_ring_lock() while spin_unlock() is
> > called in page_pool_ring_unlock(), because spin_lock_bh()
> > has disabled the softirq in page_pool_ring_lock(), which
> > causes inconsistency for spin lock pair calling.
> >
> > This patch fixes it by returning in_softirq state from
> > page_pool_producer_lock(), and use it to decide which
> > spin lock variant to use in page_pool_producer_unlock().
> >
> > As pool->ring has both producer and consumer lock, so
> > rename it to page_pool_producer_[un]lock() to reflect
> > the actual usage. Also move them to page_pool.c as they
> > are only used there, and remove the 'inline' as the
> > compiler may have better idea to do inlining or not.
> >
> > Fixes: 7886244736a4 ("net: page_pool: Add bulk support for ptr_ring")
> > Signed-off-by: Yunsheng Lin<linyunsheng@huawei.com>
>
> Thanks for spotting and fixing this! :-)
>
> Acked-by: Jesper Dangaard Brouer <brouer@redhat.com>
>

Acked-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>