On 10/13/22 20:12, Sidhartha Kumar wrote:
> Allows __prep_new_huge_page() to operate on a folio by converting
> set_hugetlb_cgroup*() to take in a folio.
>
> Signed-off-by: Sidhartha Kumar <sidhartha.kumar@xxxxxxxxxx>
> --- a/mm/hugetlb.c
> +++ b/mm/hugetlb.c
> @@ -1758,19 +1758,21 @@ static void __prep_account_new_huge_page(struct hstate *h, int nid)
> h->nr_huge_pages_node[nid]++;
> }
>
> -static void __prep_new_huge_page(struct hstate *h, struct page *page)
> +static void __prep_new_hugetlb_folio(struct hstate *h, struct folio *folio)
> {
> - hugetlb_vmemmap_optimize(h, page);
> - INIT_LIST_HEAD(&page->lru);
> - set_compound_page_dtor(page, HUGETLB_PAGE_DTOR);
> - hugetlb_set_page_subpool(page, NULL);
> - set_hugetlb_cgroup(page, NULL);
> - set_hugetlb_cgroup_rsvd(page, NULL);
> + hugetlb_vmemmap_optimize(h, &folio->page);
> + INIT_LIST_HEAD(&folio->lru);
> + folio->_folio_dtor = HUGETLB_PAGE_DTOR;
Seems like we should have a routine 'set_folio_dtor' that has the same
functionality as set_compound_page_dtor. Here, we loose the check for a
valid DTOR value (although not terribly valuable).
Not required for this patch, but something to note.
> + hugetlb_set_folio_subpool(folio, NULL);
> + set_hugetlb_cgroup(folio, NULL);
> + set_hugetlb_cgroup_rsvd(folio, NULL);
> }
>
> static void prep_new_huge_page(struct hstate *h, struct page *page, int nid)
> {
> - __prep_new_huge_page(h, page);
> + struct folio *folio = page_folio(page);
> +
> + __prep_new_hugetlb_folio(h, folio);
> spin_lock_irq(&hugetlb_lock);
> __prep_account_new_huge_page(h, nid);
> spin_unlock_irq(&hugetlb_lock);
> @@ -2731,8 +2733,10 @@ static int alloc_and_dissolve_huge_page(struct hstate *h, struct page *old_page,
> struct list_head *list)
> {
> gfp_t gfp_mask = htlb_alloc_mask(h) | __GFP_THISNODE;
> - int nid = page_to_nid(old_page);
> + struct folio *old_folio = page_folio(old_page);
> + int nid = folio_nid(old_folio);
> struct page *new_page;
> + struct folio *new_folio;
> int ret = 0;
>
> /*
> @@ -2745,16 +2749,17 @@ static int alloc_and_dissolve_huge_page(struct hstate *h, struct page *old_page,
> new_page = alloc_buddy_huge_page(h, gfp_mask, nid, NULL, NULL);
> if (!new_page)
> return -ENOMEM;
> - __prep_new_huge_page(h, new_page);
> + new_folio = page_folio(new_page);
> + __prep_new_hugetlb_folio(h, new_folio);
>
> retry:
> spin_lock_irq(&hugetlb_lock);
> - if (!PageHuge(old_page)) {
> + if (!folio_test_hugetlb(old_folio)) {
> /*
> * Freed from under us. Drop new_page too.
> */
> goto free_new;
> - } else if (page_count(old_page)) {
> + } else if (folio_ref_count(old_folio)) {
> /*
> * Someone has grabbed the page, try to isolate it here.
> * Fail with -EBUSY if not possible.
> @@ -2763,7 +2768,7 @@ static int alloc_and_dissolve_huge_page(struct hstate *h, struct page *old_page,
> ret = isolate_hugetlb(old_page, list);
> spin_lock_irq(&hugetlb_lock);
> goto free_new;
> - } else if (!HPageFreed(old_page)) {
> + } else if (!folio_test_hugetlb(old_folio)) {
Should that be?
} else if (!folio_test_hugetlb_freed(old_folio)) {
--
Mike Kravetz
> /*
> * Page's refcount is 0 but it has not been enqueued in the
> * freelist yet. Race window is small, so we can succeed here if
> @@ -2801,7 +2806,7 @@ static int alloc_and_dissolve_huge_page(struct hstate *h, struct page *old_page,
> free_new:
> spin_unlock_irq(&hugetlb_lock);
> /* Page has a zero ref count, but needs a ref to be freed */
> - set_page_refcounted(new_page);
> + folio_ref_unfreeze(new_folio, 1);
> update_and_free_page(h, new_page, false);
>
> return ret;
