X-Git-Url: https://git.openpandora.org/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=mm%2Fpage-writeback.c;h=ea3f83b21197edbb5d8b50e78b7a27d3473c8796;hb=e07518e9ce84547ef7a81478dbd3fed1539726da;hp=50f08241f9815668d73b1adfcd5c9585f11bbc15;hpb=2cfab8d74ebfbe06ce2947117945c4f45a5915ec;p=pandora-kernel.git

diff --git a/mm/page-writeback.c b/mm/page-writeback.c
index 50f08241f981..ea3f83b21197 100644
--- a/mm/page-writeback.c
+++ b/mm/page-writeback.c
@@ -1800,6 +1800,24 @@ int __set_page_dirty_nobuffers(struct page *page)
 }
 EXPORT_SYMBOL(__set_page_dirty_nobuffers);
 
+/*
+ * Call this whenever redirtying a page, to de-account the dirty counters
+ * (NR_DIRTIED, BDI_DIRTIED, tsk->nr_dirtied), so that they match the written
+ * counters (NR_WRITTEN, BDI_WRITTEN) in long term. The mismatches will lead to
+ * systematic errors in balanced_dirty_ratelimit and the dirty pages position
+ * control.
+ */
+void account_page_redirty(struct page *page)
+{
+	struct address_space *mapping = page->mapping;
+	if (mapping && mapping_cap_account_dirty(mapping)) {
+		current->nr_dirtied--;
+		dec_zone_page_state(page, NR_DIRTIED);
+		dec_bdi_stat(mapping->backing_dev_info, BDI_DIRTIED);
+	}
+}
+EXPORT_SYMBOL(account_page_redirty);
+
 /*
  * When a writepage implementation decides that it doesn't want to write this
  * page for some reason, it should redirty the locked page via
@@ -1808,6 +1826,7 @@ EXPORT_SYMBOL(__set_page_dirty_nobuffers);
 int redirty_page_for_writepage(struct writeback_control *wbc, struct page *page)
 {
 	wbc->pages_skipped++;
+	account_page_redirty(page);
 	return __set_page_dirty_nobuffers(page);
 }
 EXPORT_SYMBOL(redirty_page_for_writepage);