mm/hugetlb: convert isolate_or_dissolve_huge_page to folios

Removes a call to compound_head() by using a folio when operating on the
head page of a hugetlb compound page.

Link: https://lkml.kernel.org/r/20221101223059.460937-6-sidhartha.kumar@oracle.com
Signed-off-by: Sidhartha Kumar <sidhartha.kumar@oracle.com>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Reviewed-by: Muchun Song <songmuchun@bytedance.com>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Cc: Bui Quang Minh <minhquangbui99@gmail.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Mina Almasry <almasrymina@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 05a8328..666a771 100644 (file)
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -2832,7 +2832,7 @@ free_new:
 int isolate_or_dissolve_huge_page(struct page *page, struct list_head *list)
 {
        struct hstate *h;
-       struct page *head;
+       struct folio *folio = page_folio(page);
        int ret = -EBUSY;
 
        /*
@@ -2841,9 +2841,8 @@ int isolate_or_dissolve_huge_page(struct page *page, struct list_head *list)
         * Return success when racing as if we dissolved the page ourselves.
         */
        spin_lock_irq(&hugetlb_lock);
-       if (PageHuge(page)) {
-               head = compound_head(page);
-               h = page_hstate(head);
+       if (folio_test_hugetlb(folio)) {
+               h = folio_hstate(folio);
        } else {
                spin_unlock_irq(&hugetlb_lock);
                return 0;
@@ -2858,10 +2857,10 @@ int isolate_or_dissolve_huge_page(struct page *page, struct list_head *list)
        if (hstate_is_gigantic(h))
                return -ENOMEM;
 
-       if (page_count(head) && !isolate_hugetlb(head, list))
+       if (folio_ref_count(folio) && !isolate_hugetlb(&folio->page, list))
                ret = 0;
-       else if (!page_count(head))
-               ret = alloc_and_dissolve_huge_page(h, head, list);
+       else if (!folio_ref_count(folio))
+               ret = alloc_and_dissolve_huge_page(h, &folio->page, list);
 
        return ret;
 }