Thanks. I've been working on converting most of the code in
migrate_device.c to use folios to add support for device-private THP
migration and had this exact change so feel free to add:
Reviewed-by: Alistair Popple <apopple@xxxxxxxxxx>
"Matthew Wilcox (Oracle)" <willy@xxxxxxxxxxxxx> writes:
> Replaces five calls to compound_head() with one.
>
> Signed-off-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
> ---
> mm/migrate_device.c | 23 ++++++++++++-----------
> 1 file changed, 12 insertions(+), 11 deletions(-)
>
> diff --git a/mm/migrate_device.c b/mm/migrate_device.c
> index 8ac1f79f754a..81193363f8cd 100644
> --- a/mm/migrate_device.c
> +++ b/mm/migrate_device.c
> @@ -564,6 +564,7 @@ static void migrate_vma_insert_page(struct migrate_vma *migrate,
> struct page *page,
> unsigned long *src)
> {
> + struct folio *folio = page_folio(page);
> struct vm_area_struct *vma = migrate->vma;
> struct mm_struct *mm = vma->vm_mm;
> bool flush = false;
> @@ -596,17 +597,17 @@ static void migrate_vma_insert_page(struct migrate_vma *migrate,
> goto abort;
> if (unlikely(anon_vma_prepare(vma)))
> goto abort;
> - if (mem_cgroup_charge(page_folio(page), vma->vm_mm, GFP_KERNEL))
> + if (mem_cgroup_charge(folio, vma->vm_mm, GFP_KERNEL))
> goto abort;
>
> /*
> - * The memory barrier inside __SetPageUptodate makes sure that
> - * preceding stores to the page contents become visible before
> + * The memory barrier inside __folio_mark_uptodate makes sure that
> + * preceding stores to the folio contents become visible before
> * the set_pte_at() write.
> */
> - __SetPageUptodate(page);
> + __folio_mark_uptodate(folio);
>
> - if (is_device_private_page(page)) {
> + if (folio_is_device_private(folio)) {
> swp_entry_t swp_entry;
>
> if (vma->vm_flags & VM_WRITE)
> @@ -617,8 +618,8 @@ static void migrate_vma_insert_page(struct migrate_vma *migrate,
> page_to_pfn(page));
> entry = swp_entry_to_pte(swp_entry);
> } else {
> - if (is_zone_device_page(page) &&
> - !is_device_coherent_page(page)) {
> + if (folio_is_zone_device(folio) &&
> + !folio_is_device_coherent(folio)) {
> pr_warn_once("Unsupported ZONE_DEVICE page type.\n");
> goto abort;
> }
> @@ -652,10 +653,10 @@ static void migrate_vma_insert_page(struct migrate_vma *migrate,
> goto unlock_abort;
>
> inc_mm_counter(mm, MM_ANONPAGES);
> - page_add_new_anon_rmap(page, vma, addr);
> - if (!is_zone_device_page(page))
> - lru_cache_add_inactive_or_unevictable(page, vma);
> - get_page(page);
> + folio_add_new_anon_rmap(folio, vma, addr);
> + if (!folio_is_zone_device(folio))
> + folio_add_lru_vma(folio, vma);
> + folio_get(folio);
>
> if (flush) {
> flush_cache_page(vma, addr, pte_pfn(orig_pte));
