summaryrefslogtreecommitdiffstats
path: root/mm/page-writeback.c
diff options
context:
space:
mode:
Diffstat (limited to 'mm/page-writeback.c')
-rw-r--r--mm/page-writeback.c19
1 files changed, 19 insertions, 0 deletions
diff --git a/mm/page-writeback.c b/mm/page-writeback.c
index 5d1ef5d8613a..96b3e7aa705c 100644
--- a/mm/page-writeback.c
+++ b/mm/page-writeback.c
@@ -1825,6 +1825,24 @@ 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
* redirty_page_for_writepage() and it should then unlock the page and return 0
@@ -1832,6 +1850,7 @@ 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);