1 files changed, 7 insertions, 11 deletions

diff --git a/mm/mlock.c b/mm/mlock.c
index 008ea70b7afa..1ada366570cb 100644
--- a/mm/mlock.c
+++ b/mm/mlock.c
@@ -66,14 +66,10 @@ void __clear_page_mlock(struct page *page)
                 putback_lru_page(page);
         } else {
                 /*
-                 * Page not on the LRU yet.  Flush all pagevecs and retry.
+                 * We lost the race. the page already moved to evictable list.
                  */
-                lru_add_drain_all();
-                if (!isolate_lru_page(page))
-                        putback_lru_page(page);
-                else if (PageUnevictable(page))
+                if (PageUnevictable(page))
                         count_vm_event(UNEVICTABLE_PGSTRANDED);
-
         }
 }
 
@@ -166,7 +162,7 @@ static long __mlock_vma_pages_range(struct vm_area_struct *vma,
         unsigned long addr = start;
         struct page *pages[16]; /* 16 gives a reasonable batch */
         int nr_pages = (end - start) / PAGE_SIZE;
-        int ret;
+        int ret = 0;
         int gup_flags = 0;
 
         VM_BUG_ON(start & ~PAGE_MASK);
@@ -187,8 +183,6 @@ static long __mlock_vma_pages_range(struct vm_area_struct *vma,
         if (vma->vm_flags & VM_WRITE)
                 gup_flags |= GUP_FLAGS_WRITE;
 
-        lru_add_drain_all();    /* push cached pages to LRU */
-
         while (nr_pages > 0) {
                 int i;
 
@@ -251,8 +245,6 @@ static long __mlock_vma_pages_range(struct vm_area_struct *vma,
                 ret = 0;
         }
 
-        lru_add_drain_all();    /* to update stats */
-
         return ret;     /* count entire vma as locked_vm */
 }
 
@@ -546,6 +538,8 @@ asmlinkage long sys_mlock(unsigned long start, size_t len)
         if (!can_do_mlock())
                 return -EPERM;
 
+        lru_add_drain_all();    /* flush pagevec */
+
         down_write(&current->mm->mmap_sem);
         len = PAGE_ALIGN(len + (start & ~PAGE_MASK));
         start &= PAGE_MASK;
@@ -612,6 +606,8 @@ asmlinkage long sys_mlockall(int flags)
         if (!can_do_mlock())
                 goto out;
 
+        lru_add_drain_all();    /* flush pagevec */
+
         down_write(&current->mm->mmap_sem);
 
         lock_limit = current->signal->rlim[RLIMIT_MEMLOCK].rlim_cur;