writeback: make laptop_mode_timer_fn() handle multiple bdi_writeback's

For cgroup writeback support, all bdi-wide operations should be
distributed to all its wb's (bdi_writeback's).

This patch updates laptop_mode_timer_fn() so that it invokes
wb_start_writeback() on all wb's rather than just the root one.  As
the intent is writing out all dirty data, there's no reason to split
the number of pages to write.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Jan Kara <jack@suse.cz>
Signed-off-by: Jens Axboe <axboe@fb.com>
This commit is contained in:
Tejun Heo 2015-05-22 17:13:52 -04:00 committed by Jens Axboe
parent c00ddad39f
commit a06fd6b102

View File

@ -1723,14 +1723,20 @@ void laptop_mode_timer_fn(unsigned long data)
struct request_queue *q = (struct request_queue *)data;
int nr_pages = global_page_state(NR_FILE_DIRTY) +
global_page_state(NR_UNSTABLE_NFS);
struct bdi_writeback *wb;
struct wb_iter iter;
/*
* We want to write everything out, not just down to the dirty
* threshold
*/
if (bdi_has_dirty_io(&q->backing_dev_info))
wb_start_writeback(&q->backing_dev_info.wb, nr_pages, true,
WB_REASON_LAPTOP_TIMER);
if (!bdi_has_dirty_io(&q->backing_dev_info))
return;
bdi_for_each_wb(wb, &q->backing_dev_info, &iter, 0)
if (wb_has_dirty_io(wb))
wb_start_writeback(wb, nr_pages, true,
WB_REASON_LAPTOP_TIMER);
}
/*