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-rw-r--r--mm/rmap.c65
1 files changed, 38 insertions, 27 deletions
diff --git a/mm/rmap.c b/mm/rmap.c
index ebee816..869aaa3 100644
--- a/mm/rmap.c
+++ b/mm/rmap.c
@@ -49,6 +49,7 @@
#include <linux/swapops.h>
#include <linux/slab.h>
#include <linux/init.h>
+#include <linux/ksm.h>
#include <linux/rmap.h>
#include <linux/rcupdate.h>
#include <linux/module.h>
@@ -336,9 +337,9 @@ int page_mapped_in_vma(struct page *page, struct vm_area_struct *vma)
* Subfunctions of page_referenced: page_referenced_one called
* repeatedly from either page_referenced_anon or page_referenced_file.
*/
-static int page_referenced_one(struct page *page, struct vm_area_struct *vma,
- unsigned long address, unsigned int *mapcount,
- unsigned long *vm_flags)
+int page_referenced_one(struct page *page, struct vm_area_struct *vma,
+ unsigned long address, unsigned int *mapcount,
+ unsigned long *vm_flags)
{
struct mm_struct *mm = vma->vm_mm;
pte_t *pte;
@@ -507,28 +508,33 @@ int page_referenced(struct page *page,
unsigned long *vm_flags)
{
int referenced = 0;
+ int we_locked = 0;
if (TestClearPageReferenced(page))
referenced++;
*vm_flags = 0;
if (page_mapped(page) && page_rmapping(page)) {
- if (PageAnon(page))
+ if (!is_locked && (!PageAnon(page) || PageKsm(page))) {
+ we_locked = trylock_page(page);
+ if (!we_locked) {
+ referenced++;
+ goto out;
+ }
+ }
+ if (unlikely(PageKsm(page)))
+ referenced += page_referenced_ksm(page, mem_cont,
+ vm_flags);
+ else if (PageAnon(page))
referenced += page_referenced_anon(page, mem_cont,
vm_flags);
- else if (is_locked)
+ else if (page->mapping)
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, vm_flags);
+ if (we_locked)
unlock_page(page);
- }
}
-
+out:
if (page_test_and_clear_young(page))
referenced++;
@@ -620,14 +626,7 @@ static void __page_set_anon_rmap(struct page *page,
BUG_ON(!anon_vma);
anon_vma = (void *) anon_vma + PAGE_MAPPING_ANON;
page->mapping = (struct address_space *) anon_vma;
-
page->index = linear_page_index(vma, address);
-
- /*
- * nr_mapped state can be updated without turning off
- * interrupts because it is not modified via interrupt.
- */
- __inc_zone_page_state(page, NR_ANON_PAGES);
}
/**
@@ -665,14 +664,21 @@ static void __page_check_anon_rmap(struct page *page,
* @vma: the vm area in which the mapping is added
* @address: the user virtual address mapped
*
- * The caller needs to hold the pte lock and the page must be locked.
+ * The caller needs to hold the pte lock, and the page must be locked in
+ * the anon_vma case: to serialize mapping,index checking after setting.
*/
void page_add_anon_rmap(struct page *page,
struct vm_area_struct *vma, unsigned long address)
{
+ int first = atomic_inc_and_test(&page->_mapcount);
+ if (first)
+ __inc_zone_page_state(page, NR_ANON_PAGES);
+ if (unlikely(PageKsm(page)))
+ return;
+
VM_BUG_ON(!PageLocked(page));
VM_BUG_ON(address < vma->vm_start || address >= vma->vm_end);
- if (atomic_inc_and_test(&page->_mapcount))
+ if (first)
__page_set_anon_rmap(page, vma, address);
else
__page_check_anon_rmap(page, vma, address);
@@ -694,6 +700,7 @@ void page_add_new_anon_rmap(struct page *page,
VM_BUG_ON(address < vma->vm_start || address >= vma->vm_end);
SetPageSwapBacked(page);
atomic_set(&page->_mapcount, 0); /* increment count (starts at -1) */
+ __inc_zone_page_state(page, NR_ANON_PAGES);
__page_set_anon_rmap(page, vma, address);
if (page_evictable(page, vma))
lru_cache_add_lru(page, LRU_ACTIVE_ANON);
@@ -760,8 +767,8 @@ void page_remove_rmap(struct page *page)
* Subfunctions of try_to_unmap: try_to_unmap_one called
* repeatedly from either try_to_unmap_anon or try_to_unmap_file.
*/
-static int try_to_unmap_one(struct page *page, struct vm_area_struct *vma,
- unsigned long address, enum ttu_flags flags)
+int try_to_unmap_one(struct page *page, struct vm_area_struct *vma,
+ unsigned long address, enum ttu_flags flags)
{
struct mm_struct *mm = vma->vm_mm;
pte_t *pte;
@@ -1156,7 +1163,9 @@ int try_to_unmap(struct page *page, enum ttu_flags flags)
BUG_ON(!PageLocked(page));
- if (PageAnon(page))
+ if (unlikely(PageKsm(page)))
+ ret = try_to_unmap_ksm(page, flags);
+ else if (PageAnon(page))
ret = try_to_unmap_anon(page, flags);
else
ret = try_to_unmap_file(page, flags);
@@ -1177,15 +1186,17 @@ int try_to_unmap(struct page *page, enum ttu_flags flags)
*
* SWAP_AGAIN - no vma is holding page mlocked, or,
* SWAP_AGAIN - page mapped in mlocked vma -- couldn't acquire mmap sem
+ * SWAP_FAIL - page cannot be located at present
* SWAP_MLOCK - page is now mlocked.
*/
int try_to_munlock(struct page *page)
{
VM_BUG_ON(!PageLocked(page) || PageLRU(page));
- if (PageAnon(page))
+ if (unlikely(PageKsm(page)))
+ return try_to_unmap_ksm(page, TTU_MUNLOCK);
+ else if (PageAnon(page))
return try_to_unmap_anon(page, TTU_MUNLOCK);
else
return try_to_unmap_file(page, TTU_MUNLOCK);
}
-
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