2 files changed, 4 insertions, 0 deletions

diff --git a/include/trace/events/writeback.h b/include/trace/events/writeback.h
index 84ab72df953c..f345f66ae9d1 100644
--- a/include/trace/events/writeback.h
+++ b/include/trace/events/writeback.h
@@ -81,6 +81,8 @@ DEFINE_EVENT(writeback_class, name, \
         TP_ARGS(bdi))
 
 DEFINE_WRITEBACK_EVENT(writeback_nowork);
+DEFINE_WRITEBACK_EVENT(writeback_wake_thread);
+DEFINE_WRITEBACK_EVENT(writeback_wake_forker_thread);
 DEFINE_WRITEBACK_EVENT(writeback_bdi_register);
 DEFINE_WRITEBACK_EVENT(writeback_bdi_unregister);
 DEFINE_WRITEBACK_EVENT(writeback_thread_start);
diff --git a/mm/backing-dev.c b/mm/backing-dev.c
index 99890831d557..9008c4e207f6 100644
--- a/mm/backing-dev.c
+++ b/mm/backing-dev.c
@@ -310,6 +310,7 @@ static void wakeup_timer_fn(unsigned long data)
 
         spin_lock_bh(&bdi->wb_lock);
         if (bdi->wb.task) {
+                trace_writeback_wake_thread(bdi);
                 wake_up_process(bdi->wb.task);
         } else {
                 /*
@@ -317,6 +318,7 @@ static void wakeup_timer_fn(unsigned long data)
                  * In this case we have to wake-up the forker thread which
                  * should create and run the bdi thread.
                  */
+                trace_writeback_wake_forker_thread(bdi);
                 wake_up_process(default_backing_dev_info.wb.task);
         }
         spin_unlock_bh(&bdi->wb_lock);