thp: clean up __collapse_huge_page_isolate

There are duplicated places using release_pte_pages().
And release_all_pte_pages() can be removed.

Signed-off-by: Bob Liu <lliubbo@gmail.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Minchan Kim <minchan.kim@gmail.com>
Cc: Ni zhan Chen <nizhan.chen@gmail.com>
Acked-by: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 11 insertions, 27 deletions

diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index 40f17c34b415..6f022f505e88 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -1701,64 +1701,49 @@ static void release_pte_pages(pte_t *pte, pte_t *_pte)
         }
 }
 
-static void release_all_pte_pages(pte_t *pte)
-{
-        release_pte_pages(pte, pte + HPAGE_PMD_NR);
-}
-
 static int __collapse_huge_page_isolate(struct vm_area_struct *vma,
                                         unsigned long address,
                                         pte_t *pte)
 {
         struct page *page;
         pte_t *_pte;
-        int referenced = 0, isolated = 0, none = 0;
+        int referenced = 0, none = 0;
         for (_pte = pte; _pte < pte+HPAGE_PMD_NR;
              _pte++, address += PAGE_SIZE) {
                 pte_t pteval = *_pte;
                 if (pte_none(pteval)) {
                         if (++none <= khugepaged_max_ptes_none)
                                 continue;
-                        else {
-                                release_pte_pages(pte, _pte);
+                        else
                                 goto out;
-                        }
                 }
-                if (!pte_present(pteval) || !pte_write(pteval)) {
-                        release_pte_pages(pte, _pte);
+                if (!pte_present(pteval) || !pte_write(pteval))
                         goto out;
-                }
                 page = vm_normal_page(vma, address, pteval);
-                if (unlikely(!page)) {
-                        release_pte_pages(pte, _pte);
+                if (unlikely(!page))
                         goto out;
-                }
+
                 VM_BUG_ON(PageCompound(page));
                 BUG_ON(!PageAnon(page));
                 VM_BUG_ON(!PageSwapBacked(page));
 
                 /* cannot use mapcount: can't collapse if there's a gup pin */
-                if (page_count(page) != 1) {
-                        release_pte_pages(pte, _pte);
+                if (page_count(page) != 1)
                         goto out;
-                }
                 /*
                  * We can do it before isolate_lru_page because the
                  * page can't be freed from under us. NOTE: PG_lock
                  * is needed to serialize against split_huge_page
                  * when invoked from the VM.
                  */
-                if (!trylock_page(page)) {
-                        release_pte_pages(pte, _pte);
+                if (!trylock_page(page))
                         goto out;
-                }
                 /*
                  * Isolate the page to avoid collapsing an hugepage
                  * currently in use by the VM.
                  */
                 if (isolate_lru_page(page)) {
                         unlock_page(page);
-                        release_pte_pages(pte, _pte);
                         goto out;
                 }
                 /* 0 stands for page_is_file_cache(page) == false */
@@ -1771,12 +1756,11 @@ static int __collapse_huge_page_isolate(struct vm_area_struct *vma,
                     mmu_notifier_test_young(vma->vm_mm, address))
                         referenced = 1;
         }
-        if (unlikely(!referenced))
-                release_all_pte_pages(pte);
-        else
-                isolated = 1;
+        if (likely(referenced))
+                return 1;
 out:
-        return isolated;
+        release_pte_pages(pte, _pte);
+        return 0;
 }
 
 static void __collapse_huge_page_copy(pte_t *pte, struct page *page,