From 87c6a9b253520b66e7f5e8f67a37a701eaa51cee Mon Sep 17 00:00:00 2001 From: Jens Axboe <jens.axboe@oracle.com> Date: Thu, 17 Sep 2009 19:59:14 +0200 Subject: [PATCH] writeback: make balance_dirty_pages() gradually back more off Currently it just sleeps for a very short time, just 1 jiffy. If we keep looping in there, continually delay for a little longer of up to 100msec in total. That was the old limit for congestion wait. Signed-off-by: Jens Axboe <jens.axboe@oracle.com> --- mm/page-writeback.c | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-) diff --git a/mm/page-writeback.c b/mm/page-writeback.c index 2585349469e0..d1ba46441053 100644 --- a/mm/page-writeback.c +++ b/mm/page-writeback.c @@ -485,6 +485,7 @@ static void balance_dirty_pages(struct address_space *mapping) unsigned long bdi_thresh; unsigned long pages_written = 0; unsigned long write_chunk = sync_writeback_pages(); + unsigned long pause = 1; struct backing_dev_info *bdi = mapping->backing_dev_info; @@ -561,7 +562,15 @@ static void balance_dirty_pages(struct address_space *mapping) if (pages_written >= write_chunk) break; /* We've done our duty */ - schedule_timeout_interruptible(1); + schedule_timeout_interruptible(pause); + + /* + * Increase the delay for each loop, up to our previous + * default of taking a 100ms nap. + */ + pause <<= 1; + if (pause > HZ / 10) + pause = HZ / 10; } if (bdi_nr_reclaimable + bdi_nr_writeback < bdi_thresh && -- GitLab