Commit 499d05ec authored Nov 16, 2011 by Jan Kara Committed by Wu Fengguang Nov 16, 2011

mm: Make task in balance_dirty_pages() killable



There is no reason why task in balance_dirty_pages() shouldn't be killable
and it helps in recovering from some error conditions (like when filesystem
goes in error state and cannot accept writeback anymore but we still want to
kill processes using it to be able to unmount it).

There will be follow up patches to further abort the generic_perform_write()
and other filesystem write loops, to avoid large write + SIGKILL combination
exceeding the dirty limit and possibly strange OOM.

Reported-by: Kazuya Mio <k-mio@sx.jp.nec.com>
Tested-by: Kazuya Mio <k-mio@sx.jp.nec.com>
Reviewed-by: Neil Brown <neilb@suse.de>
Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>

parent 6aaf05f4

mm/page-writeback.c

+4 −1

Original line number	Diff line number	Diff line
		@@ -1133,7 +1133,7 @@ pause:
		pages_dirtied,
		pause,
		start_time);
		__set_current_state(TASK_UNINTERRUPTIBLE);
		__set_current_state(TASK_KILLABLE);
		io_schedule_timeout(pause);

		dirty_thresh = hard_dirty_limit(dirty_thresh);
		@@ -1145,6 +1145,9 @@ pause:
		*/
		if (nr_dirty < dirty_thresh)
		break;

		if (fatal_signal_pending(current))
		break;
		}

		if (!dirty_exceeded && bdi->dirty_exceeded)

Admin message