Subject: Re: [PATCH v3 09/26] arch, mm: pull out allocation of NODE_DATA to generic code

From: Jonathan Cameron <[email-masked]>
Date: Fri, 2 Aug 2024 10:55:27 +0100

On Thu,  1 Aug 2024 09:08:09 +0300
Mike Rapoport <[email-masked]> wrote:

> From: "Mike Rapoport (Microsoft)" <[email-masked]>
> 
> Architectures that support NUMA duplicate the code that allocates
> NODE_DATA on the node-local memory with slight variations in reporting
> of the addresses where the memory was allocated.
> 
> Use x86 version as the basis for the generic alloc_node_data() function
> and call this function in architecture specific numa initialization.
> 
> Round up node data size to SMP_CACHE_BYTES rather than to PAGE_SIZE like
> x86 used to do since the bootmem era when allocation granularity was
> PAGE_SIZE anyway.
> 
> Signed-off-by: Mike Rapoport (Microsoft) <[email-masked]>
> Acked-by: David Hildenbrand <[email-masked]>
> Reviewed-by: Jonathan Cameron <[email-masked]>
> Tested-by: Zi Yan <[email-masked]> # for x86_64 and arm64

One comment unrelated to this patch set as such, just made
more obvious by it.

> diff --git a/arch/powerpc/mm/numa.c b/arch/powerpc/mm/numa.c
> index 0744a9a2944b..3c1da08304d0 100644
> --- a/arch/powerpc/mm/numa.c
> +++ b/arch/powerpc/mm/numa.c
> @@ -1093,27 +1093,9 @@ void __init dump_numa_cpu_topology(void)
>  static void __init setup_node_data(int nid, u64 start_pfn, u64 end_pfn)
>  {
>  	u64 spanned_pages = end_pfn - start_pfn;

Trivial, but might as well squash this local variable into the
single place it's used.

> -	const size_t nd_size = roundup(sizeof(pg_data_t), SMP_CACHE_BYTES);
> -	u64 nd_pa;
> -	void *nd;
> -	int tnid;
> -
> -	nd_pa = memblock_phys_alloc_try_nid(nd_size, SMP_CACHE_BYTES, nid);
> -	if (!nd_pa)
> -		panic("Cannot allocate %zu bytes for node %d data\n",
> -		      nd_size, nid);
> -
> -	nd = __va(nd_pa);
> -
> -	/* report and initialize */
> -	pr_info("  NODE_DATA [mem %#010Lx-%#010Lx]\n",
> -		nd_pa, nd_pa + nd_size - 1);
> -	tnid = early_pfn_to_nid(nd_pa >> PAGE_SHIFT);
> -	if (tnid != nid)
> -		pr_info("    NODE_DATA(%d) on node %d\n", nid, tnid);
> -
> -	node_data[nid] = nd;
> -	memset(NODE_DATA(nid), 0, sizeof(pg_data_t));
> +
> +	alloc_node_data(nid);
> +
>  	NODE_DATA(nid)->node_id = nid;
>  	NODE_DATA(nid)->node_start_pfn = start_pfn;
>  	NODE_DATA(nid)->node_spanned_pages = spanned_pages;