path: root/mm
diff options
authorWu Fengguang <fengguang.wu@intel.com>2009-09-23 20:33:40 +0800
committerJens Axboe <jens.axboe@oracle.com>2009-09-25 18:08:24 +0200
commitd3ddec7635b6fb37cb49e3553bdeea59642be653 (patch)
tree662a1ea9c0eac6aa9bb07d4f67b6aad84709600c /mm
parentwriteback: balance_dirty_pages() shall write more than dirtied pages (diff)
writeback: stop background writeback when below background threshold
Treat bdi_start_writeback(0) as a special request to do background write, and stop such work when we are below the background dirty threshold. Also simplify the (nr_pages <= 0) checks. Since we already pass in nr_pages=LONG_MAX for WB_SYNC_ALL and background writes, we don't need to worry about it being decreased to zero. Reported-by: Richard Kennedy <richard@rsk.demon.co.uk> CC: Jan Kara <jack@suse.cz> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Wu Fengguang <fengguang.wu@intel.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Diffstat (limited to 'mm')
1 files changed, 3 insertions, 3 deletions
diff --git a/mm/page-writeback.c b/mm/page-writeback.c
index cbd4cba468bd..3c78fc316202 100644
--- a/mm/page-writeback.c
+++ b/mm/page-writeback.c
@@ -593,10 +593,10 @@ static void balance_dirty_pages(struct address_space *mapping,
* background_thresh, to keep the amount of dirty memory low.
if ((laptop_mode && pages_written) ||
- (!laptop_mode && ((nr_writeback = global_page_state(NR_FILE_DIRTY)
- + global_page_state(NR_UNSTABLE_NFS))
+ (!laptop_mode && ((global_page_state(NR_FILE_DIRTY)
+ + global_page_state(NR_UNSTABLE_NFS))
> background_thresh)))
- bdi_start_writeback(bdi, nr_writeback);
+ bdi_start_writeback(bdi, 0);
void set_page_dirty_balance(struct page *page, int page_mkwrite)