writeback: make balance_dirty_pages() gradually back more off (87c6a9b2) · Commits · 戴 / test

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

+10 −1

Original line number	Diff line number	Diff line
		@@ -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 &&

Admin message