Re: [PATCH v2 1/2] mm/memory_hotplug: remove reset_node_managed_pages() in hotadd_init_pgdat()

From: Michal Hocko
Date: Wed Jun 07 2023 - 06:27:36 EST


On Wed 07-06-23 02:45:48, Haifeng Xu wrote:
> managed pages has already been set to 0 in free_area_init_core_hotplug(),
> via zone_init_internals() on each zone. It's pointless to reset again.
>
> Furthermore, reset_node_managed_pages() no longer needs to be exposed
> outside of mm/memblock.c. Remove declaration in include/linux/memblock.h
> and define it as static.
>
> In addtion to this, the only caller of reset_node_managed_pages() is
> reset_all_zones_managed_pages(), which is annotated with __init, so it
> should be safe to also mark reset_node_managed_pages() as __init.
>
> Signed-off-by: Haifeng Xu <haifeng.xu@xxxxxxxxxx>
> Suggested-by: David Hildenbrand <david@xxxxxxxxxx>

Acked-by: Michal Hocko <mhocko@xxxxxxxx>

> ---
> v2:
> - unexport reset_node_managed_pages()
> - mark reset_node_managed_pages() as __init
> - update commit message
> ---
> include/linux/memblock.h | 1 -
> mm/memblock.c | 2 +-
> mm/memory_hotplug.c | 1 -
> 3 files changed, 1 insertion(+), 3 deletions(-)
>
> diff --git a/include/linux/memblock.h b/include/linux/memblock.h
> index f82ee3fac1cd..f71ff9f0ec81 100644
> --- a/include/linux/memblock.h
> +++ b/include/linux/memblock.h
> @@ -128,7 +128,6 @@ int memblock_clear_nomap(phys_addr_t base, phys_addr_t size);
>
> void memblock_free_all(void);
> void memblock_free(void *ptr, size_t size);
> -void reset_node_managed_pages(pg_data_t *pgdat);
> void reset_all_zones_managed_pages(void);
>
> /* Low level functions */
> diff --git a/mm/memblock.c b/mm/memblock.c
> index 3feafea06ab2..da4264528e1e 100644
> --- a/mm/memblock.c
> +++ b/mm/memblock.c
> @@ -2122,7 +2122,7 @@ static unsigned long __init free_low_memory_core_early(void)
>
> static int reset_managed_pages_done __initdata;
>
> -void reset_node_managed_pages(pg_data_t *pgdat)
> +static void __init reset_node_managed_pages(pg_data_t *pgdat)
> {
> struct zone *z;
>
> diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
> index 8e0fa209d533..65e385f34679 100644
> --- a/mm/memory_hotplug.c
> +++ b/mm/memory_hotplug.c
> @@ -1210,7 +1210,6 @@ static pg_data_t __ref *hotadd_init_pgdat(int nid)
> * online_pages() and offline_pages().
> * TODO: should be in free_area_init_core_hotplug?
> */
> - reset_node_managed_pages(pgdat);
> reset_node_present_pages(pgdat);
>
> return pgdat;
> --
> 2.25.1

--
Michal Hocko
SUSE Labs