On 3/29/22 18:04, David Hildenbrand wrote:
> Let's prepare for passing RMAP_EXCLUSIVE, similarly as we do for
> page_add_anon_rmap() now. RMAP_COMPOUND is implicit for hugetlb
> pages and ignored.
>
> Signed-off-by: David Hildenbrand <david@xxxxxxxxxx>
Acked-by: Vlastimil Babka <vbabka@xxxxxxx>
> ---
> include/linux/rmap.h | 2 +-
> mm/migrate.c | 3 ++-
> mm/rmap.c | 9 ++++++---
> 3 files changed, 9 insertions(+), 5 deletions(-)
>
> diff --git a/include/linux/rmap.h b/include/linux/rmap.h
> index aa734d2e2b01..f47bc937c383 100644
> --- a/include/linux/rmap.h
> +++ b/include/linux/rmap.h
> @@ -191,7 +191,7 @@ void page_add_file_rmap(struct page *, struct vm_area_struct *,
> void page_remove_rmap(struct page *, struct vm_area_struct *,
> bool compound);
> void hugepage_add_anon_rmap(struct page *, struct vm_area_struct *,
> - unsigned long address);
> + unsigned long address, rmap_t flags);
> void hugepage_add_new_anon_rmap(struct page *, struct vm_area_struct *,
> unsigned long address);
>
> diff --git a/mm/migrate.c b/mm/migrate.c
> index 436f0ec2da03..48db9500d20e 100644
> --- a/mm/migrate.c
> +++ b/mm/migrate.c
> @@ -232,7 +232,8 @@ static bool remove_migration_pte(struct folio *folio,
> pte = pte_mkhuge(pte);
> pte = arch_make_huge_pte(pte, shift, vma->vm_flags);
> if (folio_test_anon(folio))
> - hugepage_add_anon_rmap(new, vma, pvmw.address);
> + hugepage_add_anon_rmap(new, vma, pvmw.address,
> + RMAP_NONE);
> else
> page_dup_file_rmap(new, true);
> set_huge_pte_at(vma->vm_mm, pvmw.address, pvmw.pte, pte);
> diff --git a/mm/rmap.c b/mm/rmap.c
> index 71bf881da2a6..b972eb8f351b 100644
> --- a/mm/rmap.c
> +++ b/mm/rmap.c
> @@ -2347,9 +2347,11 @@ void rmap_walk_locked(struct folio *folio, const struct rmap_walk_control *rwc)
> * The following two functions are for anonymous (private mapped) hugepages.
> * Unlike common anonymous pages, anonymous hugepages have no accounting code
> * and no lru code, because we handle hugepages differently from common pages.
> + *
> + * RMAP_COMPOUND is ignored.
> */
> -void hugepage_add_anon_rmap(struct page *page,
> - struct vm_area_struct *vma, unsigned long address)
> +void hugepage_add_anon_rmap(struct page *page, struct vm_area_struct *vma,
> + unsigned long address, rmap_t flags)
> {
> struct anon_vma *anon_vma = vma->anon_vma;
> int first;
> @@ -2359,7 +2361,8 @@ void hugepage_add_anon_rmap(struct page *page,
> /* address might be in next vma when migration races vma_adjust */
> first = atomic_inc_and_test(compound_mapcount_ptr(page));
> if (first)
> - __page_set_anon_rmap(page, vma, address, 0);
> + __page_set_anon_rmap(page, vma, address,
> + !!(flags & RMAP_EXCLUSIVE));
> }
>
> void hugepage_add_new_anon_rmap(struct page *page,
