> On Sep 29, 2026, at 15:16, David Hildenbrand (Arm) <[email protected]> wrote:
>
> On 9/27/26 04:54, Muchun Song wrote:
>> HugeTLB and sparse-vmemmap each have their own helper to allocate the
>> shared vmemmap tail page used by vmemmap optimization.
>>
>> Factor that logic into a common vmemmap_shared_tail_page() helper. It
>> allocates the page through vmemmap_alloc_block(), initializes the tail
>> struct pages, and uses cmpxchg() to install the per-zone shared page.
>>
>> This removes duplicate allocation logic while handling both early boot
>> and runtime allocation through the same helper.
>>
>> Signed-off-by: Muchun Song <[email protected]>
>> Acked-by: Qi Zheng <[email protected]>
>> Acked-by: Mike Rapoport (Microsoft) <[email protected]>
>> ---
>> v5:
>> - Move this patch before CONFIG_VMEMMAP_OPTIMIZATION is introduced
>>
>> v4:
>> - Update the commit message for the renamed VMEMMAP_OPTIMIZATION config
>> - Collect Acked-by from Mike Rapoport
>>
>> v2:
>> - Collect Acked-by from Qi Zheng
>> ---
>
> [...]
>
>>
>> #ifdef CONFIG_HUGETLB_PAGE_OPTIMIZE_VMEMMAP
>> -static __meminit struct page *vmemmap_get_tail(unsigned int order, struct
>> zone *zone)
>> +struct page __ref *vmemmap_shared_tail_page(unsigned int order, struct zone
>> *zone)
>> {
>> - struct page *p, *tail;
>> - unsigned int idx;
>> - int node = zone_to_nid(zone);
>> + void *addr;
>> + struct page *page;
>> + const unsigned int idx = order - VMEMMAP_OPTIMIZATION_MIN_ORDER;
>
> Nit: constants read much nicer all the way at the top.
I can update to this next version.
>
>
> Acked-by: David Hildenbrand (Arm) <[email protected]>
Thanks.
>
> --
> Cheers,
>
> David
