The break is designed mainly to help the single task case. For the 1-dd case, it looks better to lower the break threshold to 125ms data. After all, it's not easy for the dirty pages to drop by 250ms worth of data when you only slept 200ms (note: the max pause time has been doubled for reducing overheads when there are lots of concurrent dirtiers). Signed-off-by: Wu Fengguang <fengguang.wu@xxxxxxxxx> --- mm/page-writeback.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) --- linux-next.orig/mm/page-writeback.c 2010-12-09 12:19:22.000000000 +0800 +++ linux-next/mm/page-writeback.c 2010-12-09 12:26:56.000000000 +0800 @@ -652,13 +652,13 @@ static void balance_dirty_pages(struct a * bdi_dirty = nr_dirty * = (background_thresh + dirty_thresh) / 2 * >> bdi_thresh - * Then the task could be blocked for a dozen second to flush - * all the exceeded (bdi_dirty - bdi_thresh) pages. So offer a - * complementary way to break out of the loop when 250ms worth + * Then the task could be blocked for many seconds to flush all + * the exceeded (bdi_dirty - bdi_thresh) pages. So offer a + * complementary way to break out of the loop when 125ms worth * of dirty pages have been cleaned during our pause time. */ - if (nr_dirty < dirty_thresh && - bdi_prev_dirty - bdi_dirty > (long)bdi->write_bandwidth / 4) + if (nr_dirty <= dirty_thresh && + bdi_prev_dirty - bdi_dirty > (long)bdi->write_bandwidth / 8) break; bdi_prev_dirty = bdi_dirty; -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxxx For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom policy in Canada: sign http://dissolvethecrtc.ca/ Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>