summaryrefslogtreecommitdiffstats
path: root/mm/rmap.c
diff options
context:
space:
mode:
authorThomas Gleixner <tglx@linutronix.de>2012-11-21 20:31:52 +0100
committerThomas Gleixner <tglx@linutronix.de>2012-11-21 20:31:52 +0100
commit9c3f9e281697d02889c3b08922f3b30be75f56c2 (patch)
treee9f3d68e0019a47b982e2b8644f70eb66a3eff3c /mm/rmap.c
parentb8f61116c1ce342804a0897b0a80eb4df5f19453 (diff)
parentd6ad418763888f617ac5b4849823e4cd670df1dd (diff)
Merge branch 'fortglx/3.8/time' of git://git.linaro.org/people/jstultz/linux into timers/core
Fix trivial conflicts in: kernel/time/tick-sched.c Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Diffstat (limited to 'mm/rmap.c')
-rw-r--r--mm/rmap.c20
1 files changed, 15 insertions, 5 deletions
diff --git a/mm/rmap.c b/mm/rmap.c
index 7df7984d476..2ee1ef0f317 100644
--- a/mm/rmap.c
+++ b/mm/rmap.c
@@ -56,6 +56,7 @@
#include <linux/mmu_notifier.h>
#include <linux/migrate.h>
#include <linux/hugetlb.h>
+#include <linux/backing-dev.h>
#include <asm/tlbflush.h>
@@ -926,11 +927,8 @@ int page_mkclean(struct page *page)
if (page_mapped(page)) {
struct address_space *mapping = page_mapping(page);
- if (mapping) {
+ if (mapping)
ret = page_mkclean_file(mapping, page);
- if (page_test_and_clear_dirty(page_to_pfn(page), 1))
- ret = 1;
- }
}
return ret;
@@ -1116,6 +1114,7 @@ void page_add_file_rmap(struct page *page)
*/
void page_remove_rmap(struct page *page)
{
+ struct address_space *mapping = page_mapping(page);
bool anon = PageAnon(page);
bool locked;
unsigned long flags;
@@ -1138,8 +1137,19 @@ void page_remove_rmap(struct page *page)
* this if the page is anon, so about to be freed; but perhaps
* not if it's in swapcache - there might be another pte slot
* containing the swap entry, but page not yet written to swap.
+ *
+ * And we can skip it on file pages, so long as the filesystem
+ * participates in dirty tracking; but need to catch shm and tmpfs
+ * and ramfs pages which have been modified since creation by read
+ * fault.
+ *
+ * Note that mapping must be decided above, before decrementing
+ * mapcount (which luckily provides a barrier): once page is unmapped,
+ * it could be truncated and page->mapping reset to NULL at any moment.
+ * Note also that we are relying on page_mapping(page) to set mapping
+ * to &swapper_space when PageSwapCache(page).
*/
- if ((!anon || PageSwapCache(page)) &&
+ if (mapping && !mapping_cap_account_dirty(mapping) &&
page_test_and_clear_dirty(page_to_pfn(page), 1))
set_page_dirty(page);
/*