Re: [PATCH 3/4] mm/memory_hotplug: clean up try_offline_node

[Oscar Salvador]

On Mon, Feb 07, 2022 at 09:36:42PM +0800, Miaohe Lin wrote:
> We can use helper macro node_spanned_pages to check whether node spans
> pages. And we can change the parameter of check_cpu_on_node to nid as
> that's what it really cares. Thus we can further get rid of the local
> variable pgdat and improve the readability a bit.
> 
> Signed-off-by: Miaohe Lin <linmiaohe@xxxxxxxxxx>

Reviewed-by: Oscar Salvador <osalvador@xxxxxxx>

> ---
>  mm/memory_hotplug.c | 9 ++++-----
>  1 file changed, 4 insertions(+), 5 deletions(-)
> 
> diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
> index 140809e60e9a..4b9eef861ee4 100644
> --- a/mm/memory_hotplug.c
> +++ b/mm/memory_hotplug.c
> @@ -2008,12 +2008,12 @@ static int get_nr_vmemmap_pages_cb(struct memory_block *mem, void *arg)
>  	return mem->nr_vmemmap_pages;
>  }
>  
> -static int check_cpu_on_node(pg_data_t *pgdat)
> +static int check_cpu_on_node(int nid)
>  {
>  	int cpu;
>  
>  	for_each_present_cpu(cpu) {
> -		if (cpu_to_node(cpu) == pgdat->node_id)
> +		if (cpu_to_node(cpu) == nid)
>  			/*
>  			 * the cpu on this node isn't removed, and we can't
>  			 * offline this node.
> @@ -2047,7 +2047,6 @@ static int check_no_memblock_for_node_cb(struct memory_block *mem, void *arg)
>   */
>  void try_offline_node(int nid)
>  {
> -	pg_data_t *pgdat = NODE_DATA(nid);
>  	int rc;
>  
>  	/*
> @@ -2055,7 +2054,7 @@ void try_offline_node(int nid)
>  	 * offline it. A node spans memory after move_pfn_range_to_zone(),
>  	 * e.g., after the memory block was onlined.
>  	 */
> -	if (pgdat->node_spanned_pages)
> +	if (node_spanned_pages(nid))
>  		return;
>  
>  	/*
> @@ -2067,7 +2066,7 @@ void try_offline_node(int nid)
>  	if (rc)
>  		return;
>  
> -	if (check_cpu_on_node(pgdat))
> +	if (check_cpu_on_node(nid))
>  		return;
>  
>  	/*
> -- 
> 2.23.0
> 
> 

-- 
Oscar Salvador
SUSE Labs