Merge tag 'mm-hotfixes-stable-2022-05-27' of git://git.kernel.org/pub/scm/linux/kerne...

[platform/kernel/linux-rpi.git] / mm / hugetlb.c

diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 01f0e2e..7c468ac 100644 (file)
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -6755,7 +6755,14 @@ int huge_pmd_unshare(struct mm_struct *mm, struct vm_area_struct *vma,
        pud_clear(pud);
        put_page(virt_to_page(ptep));
        mm_dec_nr_pmds(mm);
-       *addr = ALIGN(*addr, HPAGE_SIZE * PTRS_PER_PTE) - HPAGE_SIZE;
+       /*
+        * This update of passed address optimizes loops sequentially
+        * processing addresses in increments of huge page size (PMD_SIZE
+        * in this case).  By clearing the pud, a PUD_SIZE area is unmapped.
+        * Update address to the 'last page' in the cleared area so that
+        * calling loop can move to first page past this area.
+        */
+       *addr |= PUD_SIZE - PMD_SIZE;
        return 1;
 }