Re: [linux-next PATCH 1/2] mm: khugepaged: add exceed_max_ptes_* helpers

Kirill A. Shutemov
2020-04-30T21:59:24Z

On Thu, Apr 30, 2020 at 06:56:21AM +0800, Yang Shi wrote:
> The max_ptes_{swap|none|shared} are defined to tune the behavior of
> khugepaged. The are checked at a couple of places with open coding.
> Replace the opencoding to exceed_pax_ptes_{swap|none_shared} helpers to
> improve the readability.
>
> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
> Cc: Hugh Dickins <hughd@google.com>
> Cc: Andrea Arcangeli <aarcange@redhat.com>
> Signed-off-by: Yang Shi <yang.shi@linux.alibaba.com>
> ---
> mm/khugepaged.c | 27 +++++++++++++++++++++------
> 1 file changed, 21 insertions(+), 6 deletions(-)
>
> diff --git a/mm/khugepaged.c b/mm/khugepaged.c
> index a02a4c5..0c8d30b 100644
> --- a/mm/khugepaged.c
> +++ b/mm/khugepaged.c
> @@ -339,6 +339,21 @@ struct attribute_group khugepaged_attr_group = {
> };
> #endif /* CONFIG_SYSFS */
>
> +static inline bool exceed_max_ptes_none(unsigned int *nr_ptes)
> +{
> + return (++(*nr_ptes) > khugepaged_max_ptes_none);
> +}
> +
> +static inline bool exceed_max_ptes_swap(unsigned int *nr_ptes)
> +{
> + return (++(*nr_ptes) > khugepaged_max_ptes_swap);
> +}
> +
> +static inline bool exceed_max_ptes_shared(unsigned int *nr_ptes)
> +{
> + return (++(*nr_ptes) > khugepaged_max_ptes_shared);
> +}
> +

Frankly, I find this ugly and confusing. Open-coded version is more
readable to me.

--
Kirill A. Shutemov