mm: do_migrate_range: reduce list_empty() check

[sfrench/cifs-2.6.git] / mm / page-writeback.c

diff --git a/mm/page-writeback.c b/mm/page-writeback.c
index e3bccac1f0255bb78373e6268aab787a370ee520..b840afa89761ce0d83690ff963385399246fa6d8 100644 (file)
--- a/mm/page-writeback.c
+++ b/mm/page-writeback.c
@@ -415,14 +415,8 @@ void global_dirty_limits(unsigned long *pbackground, unsigned long *pdirty)
 
        if (vm_dirty_bytes)
                dirty = DIV_ROUND_UP(vm_dirty_bytes, PAGE_SIZE);
-       else {
-               int dirty_ratio;
-
-               dirty_ratio = vm_dirty_ratio;
-               if (dirty_ratio < 5)
-                       dirty_ratio = 5;
-               dirty = (dirty_ratio * available_memory) / 100;
-       }
+       else
+               dirty = (vm_dirty_ratio * available_memory) / 100;
 
        if (dirty_background_bytes)
                background = DIV_ROUND_UP(dirty_background_bytes, PAGE_SIZE);
@@ -510,7 +504,7 @@ static void balance_dirty_pages(struct address_space *mapping,
                 * catch-up. This avoids (excessively) small writeouts
                 * when the bdi limits are ramping up.
                 */
-               if (nr_reclaimable + nr_writeback <
+               if (nr_reclaimable + nr_writeback <=
                                (background_thresh + dirty_thresh) / 2)
                        break;
 
@@ -542,8 +536,8 @@ static void balance_dirty_pages(struct address_space *mapping,
                 * the last resort safeguard.
                 */
                dirty_exceeded =
-                       (bdi_nr_reclaimable + bdi_nr_writeback >= bdi_thresh)
-                       || (nr_reclaimable + nr_writeback >= dirty_thresh);
+                       (bdi_nr_reclaimable + bdi_nr_writeback > bdi_thresh)
+                       || (nr_reclaimable + nr_writeback > dirty_thresh);
 
                if (!dirty_exceeded)
                        break;
@@ -1121,6 +1115,7 @@ void account_page_dirtied(struct page *page, struct address_space *mapping)
 {
        if (mapping_cap_account_dirty(mapping)) {
                __inc_zone_page_state(page, NR_FILE_DIRTY);
+               __inc_zone_page_state(page, NR_DIRTIED);
                __inc_bdi_stat(mapping->backing_dev_info, BDI_RECLAIMABLE);
                task_dirty_inc(current);
                task_io_account_write(PAGE_CACHE_SIZE);
@@ -1128,6 +1123,18 @@ void account_page_dirtied(struct page *page, struct address_space *mapping)
 }
 EXPORT_SYMBOL(account_page_dirtied);
 
+/*
+ * Helper function for set_page_writeback family.
+ * NOTE: Unlike account_page_dirtied this does not rely on being atomic
+ * wrt interrupts.
+ */
+void account_page_writeback(struct page *page)
+{
+       inc_zone_page_state(page, NR_WRITEBACK);
+       inc_zone_page_state(page, NR_WRITTEN);
+}
+EXPORT_SYMBOL(account_page_writeback);
+
 /*
  * For address_spaces which do not use buffers.  Just tag the page as dirty in
  * its radix tree.
@@ -1366,7 +1373,7 @@ int test_set_page_writeback(struct page *page)
                ret = TestSetPageWriteback(page);
        }
        if (!ret)
-               inc_zone_page_state(page, NR_WRITEBACK);
+               account_page_writeback(page);
        return ret;
 
 }