This tracks when balance_dirty_pages() tries to wakeup the flusher thread for background writeback (if it was not started already). Suggested-by: Christoph Hellwig Signed-off-by: Wu Fengguang --- fs/fs-writeback.c | 1 + include/trace/events/writeback.h | 1 + 2 files changed, 2 insertions(+) --- linux-next.orig/include/trace/events/writeback.h 2010-11-07 21:54:19.000000000 +0800 +++ linux-next/include/trace/events/writeback.h 2010-11-07 21:56:42.000000000 +0800 @@ -81,6 +81,7 @@ DEFINE_EVENT(writeback_class, name, \ TP_ARGS(bdi)) DEFINE_WRITEBACK_EVENT(writeback_nowork); +DEFINE_WRITEBACK_EVENT(writeback_wake_background); DEFINE_WRITEBACK_EVENT(writeback_wake_thread); DEFINE_WRITEBACK_EVENT(writeback_wake_forker_thread); DEFINE_WRITEBACK_EVENT(writeback_bdi_register); --- linux-next.orig/fs/fs-writeback.c 2010-11-07 21:54:19.000000000 +0800 +++ linux-next/fs/fs-writeback.c 2010-11-07 21:56:42.000000000 +0800 @@ -169,6 +169,7 @@ void bdi_start_background_writeback(stru * We just wake up the flusher thread. It will perform background * writeback as soon as there is no other work to do. */ + trace_writeback_wake_background(bdi); spin_lock_bh(&bdi->wb_lock); bdi_wakeup_flusher(bdi); spin_unlock_bh(&bdi->wb_lock); -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/