Note in the bdi_writeback structure if a task is currently being limited in balance_dirty_pages(), waiting for writeback to proceed.
Signed-off-by: Jens Axboe <[email protected]> --- include/linux/backing-dev-defs.h | 2 ++ mm/backing-dev.c | 1 + mm/page-writeback.c | 2 ++ 3 files changed, 5 insertions(+) diff --git a/include/linux/backing-dev-defs.h b/include/linux/backing-dev-defs.h index 3f103076d0bf..1212c374b928 100644 --- a/include/linux/backing-dev-defs.h +++ b/include/linux/backing-dev-defs.h @@ -116,6 +116,8 @@ struct bdi_writeback { struct list_head work_list; struct delayed_work dwork; /* work item used for writeback */ + atomic_t dirty_sleeping; /* waiting on dirty limit exceeded */ + struct list_head bdi_node; /* anchored at bdi->wb_list */ #ifdef CONFIG_CGROUP_WRITEBACK diff --git a/mm/backing-dev.c b/mm/backing-dev.c index 0c6317b7db38..41db7dff11d0 100644 --- a/mm/backing-dev.c +++ b/mm/backing-dev.c @@ -310,6 +310,7 @@ static int wb_init(struct bdi_writeback *wb, struct backing_dev_info *bdi, spin_lock_init(&wb->work_lock); INIT_LIST_HEAD(&wb->work_list); INIT_DELAYED_WORK(&wb->dwork, wb_workfn); + atomic_set(&wb->dirty_sleeping, 0); wb->congested = wb_congested_get_create(bdi, blkcg_id, gfp); if (!wb->congested) diff --git a/mm/page-writeback.c b/mm/page-writeback.c index 999792d35ccc..028a3d4d7129 100644 --- a/mm/page-writeback.c +++ b/mm/page-writeback.c @@ -1746,7 +1746,9 @@ pause: pause, start_time); __set_current_state(TASK_KILLABLE); + atomic_inc(&wb->dirty_sleeping); io_schedule_timeout(pause); + atomic_dec(&wb->dirty_sleeping); current->dirty_paused_when = now + pause; current->nr_dirtied = 0; -- 2.8.0.rc4.6.g7e4ba36
