Re: [PATCH v2 hmm 10/11] mm/hmm: Do not use list*_rcu() for hmm->ranges

[Souptick Joarder <jrdr.linux@gmail.com>]

On Fri, Jun 7, 2019 at 12:15 AM Jason Gunthorpe <jgg@ziepe.ca> wrote:
>
> From: Jason Gunthorpe <jgg@mellanox.com>
>
> This list is always read and written while holding hmm->lock so there is
> no need for the confusing _rcu annotations.
>
> Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
> Reviewed-by: Jérôme Glisse <jglisse@redhat.com>

Acked-by: Souptick Joarder <jrdr.linux@gmail.com>

> ---
>  mm/hmm.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/mm/hmm.c b/mm/hmm.c
> index c2fecb3ecb11e1..709d138dd49027 100644
> --- a/mm/hmm.c
> +++ b/mm/hmm.c
> @@ -911,7 +911,7 @@ int hmm_range_register(struct hmm_range *range,
>         mutex_lock(&hmm->lock);
>
>         range->hmm = hmm;
> -       list_add_rcu(&range->list, &hmm->ranges);
> +       list_add(&range->list, &hmm->ranges);
>
>         /*
>          * If there are any concurrent notifiers we have to wait for them for
> @@ -941,7 +941,7 @@ void hmm_range_unregister(struct hmm_range *range)
>                 return;
>
>         mutex_lock(&hmm->lock);
> -       list_del_rcu(&range->list);
> +       list_del(&range->list);
>         mutex_unlock(&hmm->lock);
>
>         /* Drop reference taken by hmm_range_register() */
> --
> 2.21.0
>