mm: fix for infinite churning of mlocked pages

[pandora-kernel.git] / mm / rmap.c

diff --git a/mm/rmap.c b/mm/rmap.c
index 23122af..0895b5c 100644 (file)
--- a/mm/rmap.c
+++ b/mm/rmap.c
@@ -333,7 +333,9 @@ static int page_mapped_in_vma(struct page *page, struct vm_area_struct *vma)
  * repeatedly from either page_referenced_anon or page_referenced_file.
  */
 static int page_referenced_one(struct page *page,
-       struct vm_area_struct *vma, unsigned int *mapcount)
+                              struct vm_area_struct *vma,
+                              unsigned int *mapcount,
+                              unsigned long *vm_flags)
 {
        struct mm_struct *mm = vma->vm_mm;
        unsigned long address;
@@ -356,6 +358,7 @@ static int page_referenced_one(struct page *page,
         */
        if (vma->vm_flags & VM_LOCKED) {
                *mapcount = 1;  /* break early from loop */
+               *vm_flags |= VM_LOCKED;
                goto out_unmap;
        }
 
@@ -381,11 +384,14 @@ out_unmap:
        (*mapcount)--;
        pte_unmap_unlock(pte, ptl);
 out:
+       if (referenced)
+               *vm_flags |= vma->vm_flags;
        return referenced;
 }
 
 static int page_referenced_anon(struct page *page,
-                               struct mem_cgroup *mem_cont)
+                               struct mem_cgroup *mem_cont,
+                               unsigned long *vm_flags)
 {
        unsigned int mapcount;
        struct anon_vma *anon_vma;
@@ -405,7 +411,8 @@ static int page_referenced_anon(struct page *page,
                 */
                if (mem_cont && !mm_match_cgroup(vma->vm_mm, mem_cont))
                        continue;
-               referenced += page_referenced_one(page, vma, &mapcount);
+               referenced += page_referenced_one(page, vma,
+                                                 &mapcount, vm_flags);
                if (!mapcount)
                        break;
        }
@@ -418,6 +425,7 @@ static int page_referenced_anon(struct page *page,
  * page_referenced_file - referenced check for object-based rmap
  * @page: the page we're checking references on.
  * @mem_cont: target memory controller
+ * @vm_flags: collect encountered vma->vm_flags who actually referenced the page
  *
  * For an object-based mapped page, find all the places it is mapped and
  * check/clear the referenced flag.  This is done by following the page->mapping
@@ -427,7 +435,8 @@ static int page_referenced_anon(struct page *page,
  * This function is only called from page_referenced for object-based pages.
  */
 static int page_referenced_file(struct page *page,
-                               struct mem_cgroup *mem_cont)
+                               struct mem_cgroup *mem_cont,
+                               unsigned long *vm_flags)
 {
        unsigned int mapcount;
        struct address_space *mapping = page->mapping;
@@ -467,7 +476,8 @@ static int page_referenced_file(struct page *page,
                 */
                if (mem_cont && !mm_match_cgroup(vma->vm_mm, mem_cont))
                        continue;
-               referenced += page_referenced_one(page, vma, &mapcount);
+               referenced += page_referenced_one(page, vma,
+                                                 &mapcount, vm_flags);
                if (!mapcount)
                        break;
        }
@@ -481,29 +491,35 @@ static int page_referenced_file(struct page *page,
  * @page: the page to test
  * @is_locked: caller holds lock on the page
  * @mem_cont: target memory controller
+ * @vm_flags: collect encountered vma->vm_flags who actually referenced the page
  *
  * Quick test_and_clear_referenced for all mappings to a page,
  * returns the number of ptes which referenced the page.
  */
-int page_referenced(struct page *page, int is_locked,
-                       struct mem_cgroup *mem_cont)
+int page_referenced(struct page *page,
+                   int is_locked,
+                   struct mem_cgroup *mem_cont,
+                   unsigned long *vm_flags)
 {
        int referenced = 0;
 
        if (TestClearPageReferenced(page))
                referenced++;
 
+       *vm_flags = 0;
        if (page_mapped(page) && page->mapping) {
                if (PageAnon(page))
-                       referenced += page_referenced_anon(page, mem_cont);
+                       referenced += page_referenced_anon(page, mem_cont,
+                                                               vm_flags);
                else if (is_locked)
-                       referenced += page_referenced_file(page, mem_cont);
+                       referenced += page_referenced_file(page, mem_cont,
+                                                               vm_flags);
                else if (!trylock_page(page))
                        referenced++;
                else {
                        if (page->mapping)
-                               referenced +=
-                                       page_referenced_file(page, mem_cont);
+                               referenced += page_referenced_file(page,
+                                                       mem_cont, vm_flags);
                        unlock_page(page);
                }
        }
@@ -688,8 +704,10 @@ void page_add_new_anon_rmap(struct page *page,
  */
 void page_add_file_rmap(struct page *page)
 {
-       if (atomic_inc_and_test(&page->_mapcount))
+       if (atomic_inc_and_test(&page->_mapcount)) {
                __inc_zone_page_state(page, NR_FILE_MAPPED);
+               mem_cgroup_update_mapped_file_stat(page, 1);
+       }
 }
 
 #ifdef CONFIG_DEBUG_VM
@@ -738,6 +756,7 @@ void page_remove_rmap(struct page *page)
                        mem_cgroup_uncharge_page(page);
                __dec_zone_page_state(page,
                        PageAnon(page) ? NR_ANON_PAGES : NR_FILE_MAPPED);
+               mem_cgroup_update_mapped_file_stat(page, -1);
                /*
                 * It would be tidy to reset the PageAnon mapping here,
                 * but that might overwrite a racing page_add_anon_rmap
@@ -1202,7 +1221,6 @@ int try_to_unmap(struct page *page, int migration)
        return ret;
 }
 
-#ifdef CONFIG_UNEVICTABLE_LRU
 /**
  * try_to_munlock - try to munlock a page
  * @page: the page to be munlocked
@@ -1226,4 +1244,4 @@ int try_to_munlock(struct page *page)
        else
                return try_to_unmap_file(page, 1, 0);
 }
-#endif
+