Re: [PATCH] mm/mm_init.c: only align start of ZONE_MOVALBE on nodes with memory

[Dev Jain <dev.jain@arm.com>]

On 11/02/25 1:59 pm, Wei Yang wrote:
> At the beginning of find_zone_movable_pfns_for_nodes(), it has properly
> set node_states[N_MEMORY] in early_calculate_totalpages().
> 
> Instead of iterate on all possible nodes, we can just do the alignment
> on nodes with memory.
> 
> Signed-off-by: Wei Yang <richard.weiyang@gmail.com>
> ---
>   mm/mm_init.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/mm/mm_init.c b/mm/mm_init.c
> index 35754a8ae6c0..3ec50b5fda12 100644
> --- a/mm/mm_init.c
> +++ b/mm/mm_init.c
> @@ -547,7 +547,7 @@ static void __init find_zone_movable_pfns_for_nodes(void)
>   
>   out2:
>   	/* Align start of ZONE_MOVABLE on all nids to MAX_ORDER_NR_PAGES */
> -	for (nid = 0; nid < MAX_NUMNODES; nid++) {
> +	for_each_node_state(nid, N_MEMORY) {
>   		unsigned long start_pfn, end_pfn;
>   
>   		zone_movable_pfn[nid] =

I have boot tested this, and also read the code and it makes sense: The 
only flag which gives the possibility of ZONE_MOVABLE is N_MEMORY, and 
it gets set in early_calculate_totalpages(), and before the label out2, 
no function plays with node_states[]. So please consider:

Reviewed-by: Dev Jain <dev.jain@arm.com>