On Thu, Jun 01, 2023 at 06:35:36AM +0000, Haifeng Xu wrote:
> For empty zone, it's unnecessary to account for pages used by memmap.
> Also, the pages reserved in dma zone can be ignored.
>
> Signed-off-by: Haifeng Xu <haifeng.xu@xxxxxxxxxx>
> ---
> mm/mm_init.c | 11 +++++++----
> 1 file changed, 7 insertions(+), 4 deletions(-)
>
> diff --git a/mm/mm_init.c b/mm/mm_init.c
> index 232efac9a929..b82718d596c3 100644
> --- a/mm/mm_init.c
> +++ b/mm/mm_init.c
> @@ -1543,6 +1543,13 @@ static void __init free_area_init_core(struct pglist_data *pgdat)
> size = zone->spanned_pages;
> freesize = zone->present_pages;
>
> + if (!size) {
> + nr_kernel_pages += 0;
> + nr_all_pages += 0;
Please drop these, they are nops anyway.
> + zone_init_internals(zone, j, nid, 0);
> + continue;
> + }
> +
> /*
> * Adjust freesize so that it accounts for how much memory
> * is used by this zone for memmap. This affects the watermark
> @@ -1579,10 +1586,6 @@ static void __init free_area_init_core(struct pglist_data *pgdat)
> * And all highmem pages will be managed by the buddy system.
> */
> zone_init_internals(zone, j, nid, freesize);
> -
> - if (!size)
> - continue;
> -
> setup_usemap(zone);
> init_currently_empty_zone(zone, zone->zone_start_pfn, size);
> }
> --
> 2.25.1
>
--
Sincerely yours,
Mike.
