From 028c2dd184c097809986684f2f0627eea5529fea Mon Sep 17 00:00:00 2001 From: Dave Chinner Date: Wed, 7 Jul 2010 13:24:07 +1000 Subject: writeback: Add tracing to balance_dirty_pages Tracing high level background writeback events is good, but it doesn't give the entire picture. Add visibility into write throttling to catch IO dispatched by foreground throttling of processing dirtying lots of pages. Signed-off-by: Dave Chinner Signed-off-by: Jens Axboe --- mm/page-writeback.c | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'mm') diff --git a/mm/page-writeback.c b/mm/page-writeback.c index 37498ef61548..d556cd829af6 100644 --- a/mm/page-writeback.c +++ b/mm/page-writeback.c @@ -34,6 +34,7 @@ #include #include #include +#include /* * After a CPU has dirtied this many pages, balance_dirty_pages_ratelimited @@ -535,11 +536,13 @@ static void balance_dirty_pages(struct address_space *mapping, * threshold otherwise wait until the disk writes catch * up. */ + trace_wbc_balance_dirty_start(&wbc, bdi); if (bdi_nr_reclaimable > bdi_thresh) { writeback_inodes_wb(&bdi->wb, &wbc); pages_written += write_chunk - wbc.nr_to_write; get_dirty_limits(&background_thresh, &dirty_thresh, &bdi_thresh, bdi); + trace_wbc_balance_dirty_written(&wbc, bdi); } /* @@ -565,6 +568,7 @@ static void balance_dirty_pages(struct address_space *mapping, if (pages_written >= write_chunk) break; /* We've done our duty */ + trace_wbc_balance_dirty_wait(&wbc, bdi); __set_current_state(TASK_INTERRUPTIBLE); io_schedule_timeout(pause); -- cgit v1.2.3