On 19.08.22 11:30, Wupeng Ma wrote:
> From: Ma Wupeng <mawupeng1@xxxxxxxxxx>
>
> Since min_free_kbytes is based on gfp_zone(GFP_USER) which does not include
> zone movable. However zone movable will get its min share in
> __setup_per_zone_wmarks() which does not make any sense.
>
> And like highmem pages, __GFP_HIGH and PF_MEMALLOC allocations usually
> don't need movable pages, so there is no need to assign min pages for zone
> movable.
>
> Let's cap pages_min for zone movable to a small value here just link
> highmem pages.
>
> Signed-off-by: Ma Wupeng <mawupeng1@xxxxxxxxxx>
> ---
> mm/page_alloc.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/mm/page_alloc.c b/mm/page_alloc.c
> index e5486d47406e..ff644205370f 100644
> --- a/mm/page_alloc.c
> +++ b/mm/page_alloc.c
> @@ -8638,7 +8638,7 @@ static void __setup_per_zone_wmarks(void)
>
> /* Calculate total number of !ZONE_HIGHMEM pages */
> for_each_zone(zone) {
> - if (!is_highmem(zone))
> + if (!is_highmem(zone) && zone_idx(zone) != ZONE_MOVABLE)
> lowmem_pages += zone_managed_pages(zone);
> }
>
> @@ -8648,7 +8648,7 @@ static void __setup_per_zone_wmarks(void)
> spin_lock_irqsave(&zone->lock, flags);
> tmp = (u64)pages_min * zone_managed_pages(zone);
> do_div(tmp, lowmem_pages);
> - if (is_highmem(zone)) {
> + if (is_highmem(zone) || zone_idx(zone) == ZONE_MOVABLE) {
> /*
> * __GFP_HIGH and PF_MEMALLOC allocations usually don't
> * need highmem pages, so cap pages_min to a small
This kind-off makes sense to me, but I'm not completely sure about all
implications. We most certainly should update the comment as well.
--
Thanks,
David / dhildenb
