diff options
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/fs-writeback.c | 102 |
1 files changed, 32 insertions, 70 deletions
diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c index 21f46fb3a10..8067d3719e9 100644 --- a/fs/fs-writeback.c +++ b/fs/fs-writeback.c @@ -22,7 +22,6 @@ #include <linux/mm.h> #include <linux/pagemap.h> #include <linux/kthread.h> -#include <linux/freezer.h> #include <linux/writeback.h> #include <linux/blkdev.h> #include <linux/backing-dev.h> @@ -88,20 +87,6 @@ static inline struct inode *wb_inode(struct list_head *head) #define CREATE_TRACE_POINTS #include <trace/events/writeback.h> -/* Wakeup flusher thread or forker thread to fork it. Requires bdi->wb_lock. */ -static void bdi_wakeup_flusher(struct backing_dev_info *bdi) -{ - if (bdi->wb.task) { - wake_up_process(bdi->wb.task); - } else { - /* - * The bdi thread isn't there, wake up the forker thread which - * will create and run it. - */ - wake_up_process(default_backing_dev_info.wb.task); - } -} - static void bdi_queue_work(struct backing_dev_info *bdi, struct wb_writeback_work *work) { @@ -109,10 +94,9 @@ static void bdi_queue_work(struct backing_dev_info *bdi, spin_lock_bh(&bdi->wb_lock); list_add_tail(&work->list, &bdi->work_list); - if (!bdi->wb.task) - trace_writeback_nothread(bdi, work); - bdi_wakeup_flusher(bdi); spin_unlock_bh(&bdi->wb_lock); + + mod_delayed_work(bdi_wq, &bdi->wb.dwork, 0); } static void @@ -127,10 +111,8 @@ __bdi_start_writeback(struct backing_dev_info *bdi, long nr_pages, */ work = kzalloc(sizeof(*work), GFP_ATOMIC); if (!work) { - if (bdi->wb.task) { - trace_writeback_nowork(bdi); - wake_up_process(bdi->wb.task); - } + trace_writeback_nowork(bdi); + mod_delayed_work(bdi_wq, &bdi->wb.dwork, 0); return; } @@ -177,9 +159,7 @@ void bdi_start_background_writeback(struct backing_dev_info *bdi) * writeback as soon as there is no other work to do. */ trace_writeback_wake_background(bdi); - spin_lock_bh(&bdi->wb_lock); - bdi_wakeup_flusher(bdi); - spin_unlock_bh(&bdi->wb_lock); + mod_delayed_work(bdi_wq, &bdi->wb.dwork, 0); } /* @@ -1020,66 +1000,48 @@ long wb_do_writeback(struct bdi_writeback *wb, int force_wait) /* * Handle writeback of dirty data for the device backed by this bdi. Also - * wakes up periodically and does kupdated style flushing. + * reschedules periodically and does kupdated style flushing. */ -int bdi_writeback_thread(void *data) +void bdi_writeback_workfn(struct work_struct *work) { - struct bdi_writeback *wb = data; + struct bdi_writeback *wb = container_of(to_delayed_work(work), + struct bdi_writeback, dwork); struct backing_dev_info *bdi = wb->bdi; long pages_written; current->flags |= PF_SWAPWRITE; - set_freezable(); - wb->last_active = jiffies; - - /* - * Our parent may run at a different priority, just set us to normal - */ - set_user_nice(current, 0); - - trace_writeback_thread_start(bdi); - while (!kthread_freezable_should_stop(NULL)) { + if (likely(!current_is_workqueue_rescuer() || + list_empty(&bdi->bdi_list))) { /* - * Remove own delayed wake-up timer, since we are already awake - * and we'll take care of the periodic write-back. + * The normal path. Keep writing back @bdi until its + * work_list is empty. Note that this path is also taken + * if @bdi is shutting down even when we're running off the + * rescuer as work_list needs to be drained. */ - del_timer(&wb->wakeup_timer); - - pages_written = wb_do_writeback(wb, 0); - + do { + pages_written = wb_do_writeback(wb, 0); + trace_writeback_pages_written(pages_written); + } while (!list_empty(&bdi->work_list)); + } else { + /* + * bdi_wq can't get enough workers and we're running off + * the emergency worker. Don't hog it. Hopefully, 1024 is + * enough for efficient IO. + */ + pages_written = writeback_inodes_wb(&bdi->wb, 1024, + WB_REASON_FORKER_THREAD); trace_writeback_pages_written(pages_written); - - if (pages_written) - wb->last_active = jiffies; - - set_current_state(TASK_INTERRUPTIBLE); - if (!list_empty(&bdi->work_list) || kthread_should_stop()) { - __set_current_state(TASK_RUNNING); - continue; - } - - if (wb_has_dirty_io(wb) && dirty_writeback_interval) - schedule_timeout(msecs_to_jiffies(dirty_writeback_interval * 10)); - else { - /* - * We have nothing to do, so can go sleep without any - * timeout and save power. When a work is queued or - * something is made dirty - we will be woken up. - */ - schedule(); - } } - /* Flush any work that raced with us exiting */ - if (!list_empty(&bdi->work_list)) - wb_do_writeback(wb, 1); + if (!list_empty(&bdi->work_list) || + (wb_has_dirty_io(wb) && dirty_writeback_interval)) + queue_delayed_work(bdi_wq, &wb->dwork, + msecs_to_jiffies(dirty_writeback_interval * 10)); - trace_writeback_thread_stop(bdi); - return 0; + current->flags &= ~PF_SWAPWRITE; } - /* * Start writeback of `nr_pages' pages. If `nr_pages' is zero, write back * the whole world. |