Re: [PATCH] mm/hugetlb: remove gigantic page support for HIGHMEM

[Michal Hocko]

On Wed 11-07-18 12:59:13, Mike Kravetz wrote:
> This reverts commit ee8f248d266e ("hugetlb: add phys addr to struct
> huge_bootmem_page")
> 
> At one time powerpc used this field and supporting code. However that
> was removed with commit 79cc38ded1e1 ("powerpc/mm/hugetlb: Add support
> for reserving gigantic huge pages via kernel command line").
> 
> There are no users of this field and supporting code, so remove it.
> 
> Signed-off-by: Mike Kravetz <mike.kravetz@xxxxxxxxxx>

Acked-by: Michal Hocko <mhocko@xxxxxxxx>

> ---
>  include/linux/hugetlb.h | 3 ---
>  mm/hugetlb.c            | 9 +--------
>  2 files changed, 1 insertion(+), 11 deletions(-)
> 
> diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h
> index 36fa6a2a82e3..c39d9170a8a0 100644
> --- a/include/linux/hugetlb.h
> +++ b/include/linux/hugetlb.h
> @@ -348,9 +348,6 @@ struct hstate {
>  struct huge_bootmem_page {
>  	struct list_head list;
>  	struct hstate *hstate;
> -#ifdef CONFIG_HIGHMEM
> -	phys_addr_t phys;
> -#endif
>  };
>  
>  struct page *alloc_huge_page(struct vm_area_struct *vma,
> diff --git a/mm/hugetlb.c b/mm/hugetlb.c
> index 430be42b6ca1..e39593df050b 100644
> --- a/mm/hugetlb.c
> +++ b/mm/hugetlb.c
> @@ -2139,16 +2139,9 @@ static void __init gather_bootmem_prealloc(void)
>  	struct huge_bootmem_page *m;
>  
>  	list_for_each_entry(m, &huge_boot_pages, list) {
> +		struct page *page = virt_to_page(m);
>  		struct hstate *h = m->hstate;
> -		struct page *page;
>  
> -#ifdef CONFIG_HIGHMEM
> -		page = pfn_to_page(m->phys >> PAGE_SHIFT);
> -		memblock_free_late(__pa(m),
> -				   sizeof(struct huge_bootmem_page));
> -#else
> -		page = virt_to_page(m);
> -#endif
>  		WARN_ON(page_count(page) != 1);
>  		prep_compound_huge_page(page, h->order);
>  		WARN_ON(PageReserved(page));
> -- 
> 2.17.1

-- 
Michal Hocko
SUSE Labs