Re: [PATCH] mm/memblock: Introduce memblock_alloc_node_or_panic() helper

[Mike Rapoport]

On Thu, Jun 04, 2026 at 11:41:39AM +0800, Zhen Ni wrote:
> During early boot, several subsystems allocate memory from specific
> NUMA nodes using memblock_alloc_node(). When allocation fails, the
> typical requirement is to panic immediately.
> 
> Introduce memblock_alloc_node_or_panic() to automatically panic on
> allocation failure. This reduces repetitive error checking, improves code
> consistency across subsystems, and enhances code readability.

memblock_alloc_or_panic() made sense because it's the most used memblock
API.

Adding panic() versions for a handful of uses is unnecessary churn.

A better patch would be to update panic() messages to convey more useful
information.
 
> Signed-off-by: Zhen Ni <zhen.ni@xxxxxxxxxxxx>
> ---
>  arch/sh/mm/numa.c            | 10 ++++------
>  arch/sparc/kernel/setup_64.c | 16 ++++++----------
>  arch/x86/coco/sev/core.c     |  5 ++---
>  include/linux/memblock.h     |  6 ++++++
>  mm/memblock.c                | 22 ++++++++++++++++++++++
>  mm/mm_init.c                 | 11 ++++-------
>  mm/sparse.c                  | 13 +++++--------
>  7 files changed, 49 insertions(+), 34 deletions(-)
> 
> diff --git a/arch/sh/mm/numa.c b/arch/sh/mm/numa.c
> index 9bc212b5e762..32b01697b27f 100644
> --- a/arch/sh/mm/numa.c
> +++ b/arch/sh/mm/numa.c
> @@ -38,12 +38,10 @@ void __init setup_bootmem_node(int nid, unsigned long start, unsigned long end)
>  	__add_active_range(nid, start_pfn, end_pfn);
>  
>  	/* Node-local pgdat */
> -	NODE_DATA(nid) = memblock_alloc_node(sizeof(struct pglist_data),
> -					     SMP_CACHE_BYTES, nid);
> -	if (!NODE_DATA(nid))
> -		panic("%s: Failed to allocate %zu bytes align=0x%x nid=%d\n",
> -		      __func__, sizeof(struct pglist_data), SMP_CACHE_BYTES,
> -		      nid);
> +	NODE_DATA(nid) = memblock_alloc_node_or_panic(
> +				sizeof(struct pglist_data),
> +				SMP_CACHE_BYTES,
> +				nid);

Please don't touch this, the entire file is going away after rc1.

>  
>  	NODE_DATA(nid)->node_start_pfn = start_pfn;
>  	NODE_DATA(nid)->node_spanned_pages = end_pfn - start_pfn;

-- 
Sincerely yours,
Mike.