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>
This commit is contained in:
Jens Axboe 2009-09-17 19:59:14 +02:00
parent 3542a5c0de
commit 87c6a9b253

View File

@ -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 &&