Commit e92eebbb authored by Jan Kara's avatar Jan Kara Committed by Jens Axboe
Browse files

mm: Move updates of dirty_exceeded into one place 



Transition of wb->dirty_exceeded from 0 to 1 happens before we go to
sleep in balance_dirty_pages() while transition from 1 to 0 happens when
exiting from balance_dirty_pages(), possibly based on old values. This
does not make a lot of sense since wb->dirty_exceeded should simply
reflect whether wb is over dirty limit and so we should ratelimit
entering to balance_dirty_pages() less. Move the two updates together.

Signed-off-by: default avatarJan Kara <jack@suse.cz>
Signed-off-by: default avatarStefan Roesch <shr@fb.com>
Link: https://lore.kernel.org/r/20220623175157.1715274-3-shr@fb.com


Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent ea6813be

mm/page-writeback.c

+2 −5
Original line number Diff line number Diff line
@@ -1729,8 +1729,8 @@ static void balance_dirty_pages(struct bdi_writeback *wb, 
				sdtc = mdtc;

		}



		if (dirty_exceeded && !wb->dirty_exceeded)

			wb->dirty_exceeded = 1;

		if (dirty_exceeded != wb->dirty_exceeded)

			wb->dirty_exceeded = dirty_exceeded;



		if (time_is_before_jiffies(READ_ONCE(wb->bw_time_stamp) +

					   BANDWIDTH_INTERVAL))
@@ -1834,9 +1834,6 @@ static void balance_dirty_pages(struct bdi_writeback *wb, 
		if (fatal_signal_pending(current))

			break;

	}



	if (!dirty_exceeded && wb->dirty_exceeded)

		wb->dirty_exceeded = 0;

}



static DEFINE_PER_CPU(int, bdp_ratelimits);