tree 427e4b1f535dfa483de6b71d1f59c13fd07a0ff9
parent 5b9b357435a51ff14835c06d8b00765a4c68f313
author Wu Fengguang <fengguang.wu@intel.com> 1322969161 -0600
committer Wu Fengguang <fengguang.wu@intel.com> 1324189231 +0800

writeback: do strict bdi dirty_exceeded

This helps to reduce dirty throttling polls and hence CPU overheads.

bdi->dirty_exceeded typically only helps when suddenly starting 100+
dd's on a disk, in which case the dd's may need to poll
balance_dirty_pages() earlier than tsk->nr_dirtied_pause.

CC: Jan Kara <jack@suse.cz>
CC: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>