Re: [PATCH v10 1/3] mm: Add node_to_range lookup facility to numa_memblks

[Mike Rapoport <rppt@kernel.org>]

On Fri, Aug 01, 2025 at 06:20:27PM +0100, shiju.jose@huawei.com wrote:
> From: Shiju Jose <shiju.jose@huawei.com>
> 
> Lookup facility to retrieve memory phys lowest continuous range for
> a NUMA node is required in the numa_memblks for the ACPI RAS2 memory
> scrub use case.

If the code that needs to find the lowest contiguous range in a node runs
before we discard .init you can just use

	unsigned long pfn = node_start_pfn(nid);
	unsigned long start_pfn, end_pfn;

	memblock_search_pfn_nid(pfn, &start_pfn, &end_pfn);
 
> Suggested-by: Jonathan Cameron <jonathan.cameron@huawei.com>
> Signed-off-by: Shiju Jose <shiju.jose@huawei.com>
> ---
>  include/linux/numa.h         | 10 ++++++++++
>  include/linux/numa_memblks.h |  2 ++
>  mm/numa.c                    | 10 ++++++++++
>  mm/numa_memblks.c            | 23 +++++++++++++++++++++++
>  4 files changed, 45 insertions(+)
> 
> diff --git a/include/linux/numa.h b/include/linux/numa.h
> index e6baaf6051bc..d41e583a902d 100644
> --- a/include/linux/numa.h
> +++ b/include/linux/numa.h
> @@ -41,6 +41,10 @@ int memory_add_physaddr_to_nid(u64 start);
>  int phys_to_target_node(u64 start);
>  #endif
>  
> +#ifndef node_to_phys_lowest_continuous_range
> +int node_to_phys_lowest_continuous_range(int nid, u64 *start, u64 *end);
> +#endif
> +
>  int numa_fill_memblks(u64 start, u64 end);
>  
>  #else /* !CONFIG_NUMA */
> @@ -63,6 +67,12 @@ static inline int phys_to_target_node(u64 start)
>  	return 0;
>  }
>  
> +static inline int node_to_phys_lowest_continuous_range(int nid, u64 *start,
> +						       u64 *end)
> +{
> +	return 0;
> +}
> +
>  static inline void alloc_offline_node_data(int nid) {}
>  #endif
>  
> diff --git a/include/linux/numa_memblks.h b/include/linux/numa_memblks.h
> index 991076cba7c5..ccc53029de8b 100644
> --- a/include/linux/numa_memblks.h
> +++ b/include/linux/numa_memblks.h
> @@ -55,6 +55,8 @@ extern int phys_to_target_node(u64 start);
>  #define phys_to_target_node phys_to_target_node
>  extern int memory_add_physaddr_to_nid(u64 start);
>  #define memory_add_physaddr_to_nid memory_add_physaddr_to_nid
> +extern int node_to_phys_lowest_continuous_range(int nid, u64 *start, u64 *end);
> +#define node_to_phys_lowest_continuous_range node_to_phys_lowest_continuous_range
>  #endif /* CONFIG_NUMA_KEEP_MEMINFO */
>  
>  #endif /* CONFIG_NUMA_MEMBLKS */
> diff --git a/mm/numa.c b/mm/numa.c
> index 7d5e06fe5bd4..0affb56ef4f2 100644
> --- a/mm/numa.c
> +++ b/mm/numa.c
> @@ -59,3 +59,13 @@ int phys_to_target_node(u64 start)
>  }
>  EXPORT_SYMBOL_GPL(phys_to_target_node);
>  #endif
> +
> +#ifndef node_to_phys_lowest_continuous_range
> +int node_to_phys_lowest_continuous_range(int nid, u64 *start, u64 *end)
> +{
> +	pr_info_once("Unknown target phys addr range for node=%d\n", nid);
> +
> +	return 0;
> +}
> +EXPORT_SYMBOL_GPL(node_to_phys_lowest_continuous_range);
> +#endif
> diff --git a/mm/numa_memblks.c b/mm/numa_memblks.c
> index 541a99c4071a..9cbaa38cb92d 100644
> --- a/mm/numa_memblks.c
> +++ b/mm/numa_memblks.c
> @@ -590,4 +590,27 @@ int memory_add_physaddr_to_nid(u64 start)
>  }
>  EXPORT_SYMBOL_GPL(memory_add_physaddr_to_nid);
>  
> +static int nid_to_meminfo(struct numa_meminfo *mi, int nid, u64 *start, u64 *end)
> +{
> +	int i;
> +
> +	if (!numa_valid_node(nid))
> +		return -EINVAL;
> +
> +	for (i = 0; i < mi->nr_blks; i++) {
> +		if (mi->blk[i].nid == nid) {
> +			*start = mi->blk[i].start;
> +			*end = mi->blk[i].end;
> +			return 0;
> +		}
> +	}
> +
> +	return -ENODEV;
> +}
> +
> +int node_to_phys_lowest_continuous_range(int nid, u64 *start, u64 *end)
> +{
> +	return nid_to_meminfo(&numa_meminfo, nid, start, end);
> +}
> +EXPORT_SYMBOL_GPL(node_to_phys_lowest_continuous_range);
>  #endif /* CONFIG_NUMA_KEEP_MEMINFO */
> -- 
> 2.43.0
> 

-- 
Sincerely yours,
Mike.