mm: MADV_FREE trivial clean up

1. Page table waker already pass the vma it is processing
so we don't need to pass vma.

2. If page table entry is dirty in try_to_unmap_one, the dirtiness
should propagate to PG_dirty of the page. So, it's enough to check
only PageDirty without other pte dirty bit checking.

Signed-off-by: Minchan Kim <minchan@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/mm/madvise.c b/mm/madvise.c
index 113dc021182bb7dcbaf0d83b01c55f17c7fb5f00..f6fd3dcfb471f705020fd0c60f8975e22b5f602c 100644 (file)
--- a/mm/madvise.c
+++ b/mm/madvise.c
@@ -24,11 +24,6 @@
 
 #include <asm/tlb.h>
 
-struct madvise_free_private {
-       struct vm_area_struct *vma;
-       struct mmu_gather *tlb;
-};
-
 /*
  * Any behaviour which results in changes to the vma->vm_flags needs to
  * take mmap_sem for writing. Others, which simply traverse vmas, need
@@ -269,10 +264,9 @@ static int madvise_free_pte_range(pmd_t *pmd, unsigned long addr,
                                unsigned long end, struct mm_walk *walk)
 
 {
-       struct madvise_free_private *fp = walk->private;
-       struct mmu_gather *tlb = fp->tlb;
+       struct mmu_gather *tlb = walk->private;
        struct mm_struct *mm = tlb->mm;
-       struct vm_area_struct *vma = fp->vma;
+       struct vm_area_struct *vma = walk->vma;
        spinlock_t *ptl;
        pte_t *pte, ptent;
        struct page *page;
@@ -329,15 +323,10 @@ static void madvise_free_page_range(struct mmu_gather *tlb,
                             struct vm_area_struct *vma,
                             unsigned long addr, unsigned long end)
 {
-       struct madvise_free_private fp = {
-               .vma = vma,
-               .tlb = tlb,
-       };
-
        struct mm_walk free_walk = {
                .pmd_entry = madvise_free_pte_range,
                .mm = vma->vm_mm,
-               .private = &fp,
+               .private = tlb,
        };
 
        BUG_ON(addr >= end);

diff --git a/mm/rmap.c b/mm/rmap.c
index c9b0c47cbd9f1d6cb069710cc5f48b1274fdd4dc..311eedb143271c8fa0800f6516e133b74ddb3011 100644 (file)
--- a/mm/rmap.c
+++ b/mm/rmap.c
@@ -1376,7 +1376,6 @@ static int try_to_unmap_one(struct page *page, struct vm_area_struct *vma,
        spinlock_t *ptl;
        int ret = SWAP_AGAIN;
        enum ttu_flags flags = (enum ttu_flags)arg;
-       int dirty = 0;
 
        /* munlock has nothing to gain from examining un-locked vmas */
        if ((flags & TTU_MUNLOCK) && !(vma->vm_flags & VM_LOCKED))
@@ -1426,8 +1425,7 @@ static int try_to_unmap_one(struct page *page, struct vm_area_struct *vma,
        }
 
        /* Move the dirty bit to the physical page now the pte is gone. */
-       dirty = pte_dirty(pteval);
-       if (dirty)
+       if (pte_dirty(pteval))
                set_page_dirty(page);
 
        /* Update high watermark before we lower rss */
@@ -1473,7 +1471,7 @@ static int try_to_unmap_one(struct page *page, struct vm_area_struct *vma,
 
                if (flags & TTU_FREE) {
                        VM_BUG_ON_PAGE(PageSwapCache(page), page);
-                       if (!dirty && !PageDirty(page)) {
+                       if (!PageDirty(page)) {
                                /* It's a freeable page by MADV_FREE */
                                dec_mm_counter(mm, MM_ANONPAGES);
                                goto discard;