[PATCH 1/1] Add check for dirty_writeback_interval in bdi_wakeup_thread_delayed

[Raghavendra D Prabhu <rprabhu@wnohang.net>]

In the function bdi_wakeup_thread_delayed, no checks are performed on
dirty_writeback_interval unlike other places and timeout is being set to
zero as result, thus defeating the purpose. So, I have changed it to be
passed default value of interval which is 500 centiseconds, when it is
set to zero.
I have also verified this and tested it.

Signed-off-by: Raghavendra D Prabhu <rprabhu@wnohang.net>
---
  mm/backing-dev.c |    5 ++++-
  1 files changed, 4 insertions(+), 1 deletions(-)

diff --git a/mm/backing-dev.c b/mm/backing-dev.c
index befc875..d06533c 100644
--- a/mm/backing-dev.c
+++ b/mm/backing-dev.c
@@ -336,7 +336,10 @@ void bdi_wakeup_thread_delayed(struct backing_dev_info *bdi)
  {
  	unsigned long timeout;
  
-	timeout = msecs_to_jiffies(dirty_writeback_interval * 10);
+	if (dirty_writeback_interval)
+		timeout = msecs_to_jiffies(dirty_writeback_interval * 10);
+	else
+		timeout = msecs_to_jiffies(5000);
  	mod_timer(&bdi->wb.wakeup_timer, jiffies + timeout);
  }
  
-- 
1.7.4.4

--------------------------
Raghavendra Prabhu
GPG Id : D72BE977