Re: [PATCH] mm/mm_init: Fix the zone->managed_pages comment to match the code

[David Hildenbrand <david@redhat.com>]

On 29.12.24 19:09, Jiwen Qi wrote:
> The invocation of zone_init_internals(zone, j, nid, zone->present_pages)
> initializes zone->managed_pages to zone->present_pages. zone->present_pages
> is not 0 when the zone is not empty.
> 
> Signed-off-by: Jiwen Qi <jiwen7.qi@gmail.com>
> ---
>   mm/mm_init.c | 5 +++--
>   1 file changed, 3 insertions(+), 2 deletions(-)
> 
> diff --git a/mm/mm_init.c b/mm/mm_init.c
> index 24b68b425afb..6cf6243c4c52 100644
> --- a/mm/mm_init.c
> +++ b/mm/mm_init.c
> @@ -1567,8 +1567,9 @@ static void __init free_area_init_core(struct pglist_data *pgdat)
>   		unsigned long size = zone->spanned_pages;
>   
>   		/*
> -		 * Initialize zone->managed_pages as 0 , it will be reset
> -		 * when memblock allocator frees pages into buddy system.
> +		 * Initialize zone->managed_pages to zone->present_pages, it
> +		 * will be reset when memblock allocator frees pages into
> +		 * buddy system.


Maybe we can be a bit clearer:

"Initialize zone->managed_pages to zone->present_pages as a first rough 
estimate. memblock_free_all() will reset zone->managed_pages to 0, and
calculate the actual managed pages as they are freed to the buddy."

?

It might also make sense to mention commit 0ac5e785dcb797 in the patch 
description, that contains some more details.


-- 
Cheers,

David / dhildenb