From 603320239fb436f175c8b6bfa43d5023c47a6dc2 Mon Sep 17 00:00:00 2001 From: Artem Bityutskiy Date: Sun, 25 Jul 2010 14:29:24 +0300 Subject: writeback: add new tracepoints Add 2 new trace points to the periodic write-back wake up case, just like we do in the 'bdi_queue_work()' function. Namely, introduce: 1. trace_writeback_wake_thread(bdi) 2. trace_writeback_wake_forker_thread(bdi) The first event is triggered every time we wake up a bdi thread to start periodic background write-out. The second event is triggered only when the bdi thread does not exist and should be created by the forker thread. This patch was suggested by Dave Chinner and Christoph Hellwig. Signed-off-by: Artem Bityutskiy Signed-off-by: Jens Axboe --- include/trace/events/writeback.h | 2 ++ mm/backing-dev.c | 2 ++ 2 files changed, 4 insertions(+) diff --git a/include/trace/events/writeback.h b/include/trace/events/writeback.h index 84ab72d..f345f66 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 9989083..9008c4e 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); -- cgit v1.1