diff options
Diffstat (limited to 'mm/rmap.c')
| -rw-r--r-- | mm/rmap.c | 36 |
1 files changed, 11 insertions, 25 deletions
diff --git a/mm/rmap.c b/mm/rmap.c index 78a692827a63..b93fb540c525 100644 --- a/mm/rmap.c +++ b/mm/rmap.c @@ -1304,6 +1304,10 @@ static int try_to_unmap_one(struct page *page, struct vm_area_struct *vma, int ret = SWAP_AGAIN; enum ttu_flags flags = (enum ttu_flags)arg; + /* munlock has nothing to gain from examining un-locked vmas */ + if ((flags & TTU_MUNLOCK) && !(vma->vm_flags & VM_LOCKED)) + goto out; + pte = page_check_address(page, mm, address, &ptl, 0); if (!pte) goto out; @@ -1314,9 +1318,12 @@ static int try_to_unmap_one(struct page *page, struct vm_area_struct *vma, * skipped over this mm) then we should reactivate it. */ if (!(flags & TTU_IGNORE_MLOCK)) { - if (vma->vm_flags & VM_LOCKED) - goto out_mlock; - + if (vma->vm_flags & VM_LOCKED) { + /* Holding pte lock, we do *not* need mmap_sem here */ + mlock_vma_page(page); + ret = SWAP_MLOCK; + goto out_unmap; + } if (flags & TTU_MUNLOCK) goto out_unmap; } @@ -1421,31 +1428,10 @@ static int try_to_unmap_one(struct page *page, struct vm_area_struct *vma, out_unmap: pte_unmap_unlock(pte, ptl); - if (ret != SWAP_FAIL && !(flags & TTU_MUNLOCK)) + if (ret != SWAP_FAIL && ret != SWAP_MLOCK && !(flags & TTU_MUNLOCK)) mmu_notifier_invalidate_page(mm, address); out: return ret; - -out_mlock: - pte_unmap_unlock(pte, ptl); - - - /* - * We need mmap_sem locking, Otherwise VM_LOCKED check makes - * unstable result and race. Plus, We can't wait here because - * we now hold anon_vma->rwsem or mapping->i_mmap_rwsem. - * if trylock failed, the page remain in evictable lru and later - * vmscan could retry to move the page to unevictable lru if the - * page is actually mlocked. - */ - if (down_read_trylock(&vma->vm_mm->mmap_sem)) { - if (vma->vm_flags & VM_LOCKED) { - mlock_vma_page(page); - ret = SWAP_MLOCK; - } - up_read(&vma->vm_mm->mmap_sem); - } - return ret; } bool is_vma_temporary_stack(struct vm_area_struct *vma) |