diff options
| -rw-r--r-- | fs/fs-writeback.c | 36 | ||||
| -rw-r--r-- | include/linux/backing-dev.h | 2 | ||||
| -rw-r--r-- | mm/backing-dev.c | 73 |
3 files changed, 70 insertions, 41 deletions
diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c index 55f6e46e06f..bfa2df2c7ce 100644 --- a/fs/fs-writeback.c +++ b/fs/fs-writeback.c @@ -76,7 +76,7 @@ static void bdi_queue_work(struct backing_dev_info *bdi, { trace_writeback_queue(bdi, work); - spin_lock(&bdi->wb_lock); + spin_lock_bh(&bdi->wb_lock); list_add_tail(&work->list, &bdi->work_list); if (bdi->wb.task) { wake_up_process(bdi->wb.task); @@ -88,7 +88,7 @@ static void bdi_queue_work(struct backing_dev_info *bdi, trace_writeback_nothread(bdi, work); wake_up_process(default_backing_dev_info.wb.task); } - spin_unlock(&bdi->wb_lock); + spin_unlock_bh(&bdi->wb_lock); } static void @@ -704,13 +704,13 @@ get_next_work_item(struct backing_dev_info *bdi) { struct wb_writeback_work *work = NULL; - spin_lock(&bdi->wb_lock); + spin_lock_bh(&bdi->wb_lock); if (!list_empty(&bdi->work_list)) { work = list_entry(bdi->work_list.next, struct wb_writeback_work, list); list_del_init(&work->list); } - spin_unlock(&bdi->wb_lock); + spin_unlock_bh(&bdi->wb_lock); return work; } @@ -810,6 +810,12 @@ int bdi_writeback_thread(void *data) trace_writeback_thread_start(bdi); while (!kthread_should_stop()) { + /* + * Remove own delayed wake-up timer, since we are already awake + * and we'll take care of the preriodic write-back. + */ + del_timer(&wb->wakeup_timer); + pages_written = wb_do_writeback(wb, 0); trace_writeback_pages_written(pages_written); @@ -868,26 +874,6 @@ void wakeup_flusher_threads(long nr_pages) rcu_read_unlock(); } -/* - * This function is used when the first inode for this bdi is marked dirty. It - * wakes-up the corresponding bdi thread which should then take care of the - * periodic background write-out of dirty inodes. - */ -static void wakeup_bdi_thread(struct backing_dev_info *bdi) -{ - spin_lock(&bdi->wb_lock); - if (bdi->wb.task) - wake_up_process(bdi->wb.task); - else - /* - * When bdi tasks are inactive for long time, they are killed. - * In this case we have to wake-up the forker thread which - * should create and run the bdi thread. - */ - wake_up_process(default_backing_dev_info.wb.task); - spin_unlock(&bdi->wb_lock); -} - static noinline void block_dump___mark_inode_dirty(struct inode *inode) { if (inode->i_ino || strcmp(inode->i_sb->s_id, "bdev")) { @@ -1019,7 +1005,7 @@ out: spin_unlock(&inode_lock); if (wakeup_bdi) - wakeup_bdi_thread(bdi); + bdi_wakeup_thread_delayed(bdi); } EXPORT_SYMBOL(__mark_inode_dirty); diff --git a/include/linux/backing-dev.h b/include/linux/backing-dev.h index 71b6223e0a7..7628219e538 100644 --- a/include/linux/backing-dev.h +++ b/include/linux/backing-dev.h @@ -52,6 +52,7 @@ struct bdi_writeback { unsigned long last_active; /* last time bdi thread was active */ struct task_struct *task; /* writeback thread */ + struct timer_list wakeup_timer; /* used for delayed bdi thread wakeup */ struct list_head b_dirty; /* dirty inodes */ struct list_head b_io; /* parked for writeback */ struct list_head b_more_io; /* parked for more writeback */ @@ -105,6 +106,7 @@ void bdi_start_background_writeback(struct backing_dev_info *bdi); int bdi_writeback_thread(void *data); int bdi_has_dirty_io(struct backing_dev_info *bdi); void bdi_arm_supers_timer(void); +void bdi_wakeup_thread_delayed(struct backing_dev_info *bdi); extern spinlock_t bdi_lock; extern struct list_head bdi_list; diff --git a/mm/backing-dev.c b/mm/backing-dev.c index a9a08d88a74..cfff7225138 100644 --- a/mm/backing-dev.c +++ b/mm/backing-dev.c @@ -248,17 +248,6 @@ static int __init default_bdi_init(void) } subsys_initcall(default_bdi_init); -static void bdi_wb_init(struct bdi_writeback *wb, struct backing_dev_info *bdi) -{ - memset(wb, 0, sizeof(*wb)); - - wb->bdi = bdi; - wb->last_old_flush = jiffies; - INIT_LIST_HEAD(&wb->b_dirty); - INIT_LIST_HEAD(&wb->b_io); - INIT_LIST_HEAD(&wb->b_more_io); -} - int bdi_has_dirty_io(struct backing_dev_info *bdi) { return wb_has_dirty_io(&bdi->wb); @@ -316,6 +305,43 @@ static void sync_supers_timer_fn(unsigned long unused) bdi_arm_supers_timer(); } +static void wakeup_timer_fn(unsigned long data) +{ + struct backing_dev_info *bdi = (struct backing_dev_info *)data; + + spin_lock_bh(&bdi->wb_lock); + if (bdi->wb.task) { + wake_up_process(bdi->wb.task); + } else { + /* + * When bdi tasks are inactive for long time, they are killed. + * In this case we have to wake-up the forker thread which + * should create and run the bdi thread. + */ + wake_up_process(default_backing_dev_info.wb.task); + } + spin_unlock_bh(&bdi->wb_lock); +} + +/* + * This function is used when the first inode for this bdi is marked dirty. It + * wakes-up the corresponding bdi thread which should then take care of the + * periodic background write-out of dirty inodes. Since the write-out would + * starts only 'dirty_writeback_interval' centisecs from now anyway, we just + * set up a timer which wakes the bdi thread up later. + * + * Note, we wouldn't bother setting up the timer, but this function is on the + * fast-path (used by '__mark_inode_dirty()'), so we save few context switches + * by delaying the wake-up. + */ +void bdi_wakeup_thread_delayed(struct backing_dev_info *bdi) +{ + unsigned long timeout; + + timeout = msecs_to_jiffies(dirty_writeback_interval * 10); + mod_timer(&bdi->wb.wakeup_timer, jiffies + timeout); +} + /* * Calculate the longest interval (jiffies) bdi threads are allowed to be * inactive. @@ -353,8 +379,10 @@ static int bdi_forker_thread(void *ptr) * Temporary measure, we want to make sure we don't see * dirty data on the default backing_dev_info */ - if (wb_has_dirty_io(me) || !list_empty(&me->bdi->work_list)) + if (wb_has_dirty_io(me) || !list_empty(&me->bdi->work_list)) { + del_timer(&me->wakeup_timer); wb_do_writeback(me, 0); + } spin_lock_bh(&bdi_lock); set_current_state(TASK_INTERRUPTIBLE); @@ -386,7 +414,7 @@ static int bdi_forker_thread(void *ptr) break; } - spin_lock(&bdi->wb_lock); + spin_lock_bh(&bdi->wb_lock); /* * If there is no work to do and the bdi thread was * inactive long enough - kill it. The wb_lock is taken @@ -403,7 +431,7 @@ static int bdi_forker_thread(void *ptr) action = KILL_THREAD; break; } - spin_unlock(&bdi->wb_lock); + spin_unlock_bh(&bdi->wb_lock); } spin_unlock_bh(&bdi_lock); @@ -427,9 +455,9 @@ static int bdi_forker_thread(void *ptr) * The spinlock makes sure we do not lose * wake-ups when racing with 'bdi_queue_work()'. */ - spin_lock(&bdi->wb_lock); + spin_lock_bh(&bdi->wb_lock); bdi->wb.task = task; - spin_unlock(&bdi->wb_lock); + spin_unlock_bh(&bdi->wb_lock); } break; @@ -586,6 +614,7 @@ void bdi_unregister(struct backing_dev_info *bdi) if (bdi->dev) { trace_writeback_bdi_unregister(bdi); bdi_prune_sb(bdi); + del_timer_sync(&bdi->wb.wakeup_timer); if (!bdi_cap_flush_forker(bdi)) bdi_wb_shutdown(bdi); @@ -596,6 +625,18 @@ void bdi_unregister(struct backing_dev_info *bdi) } EXPORT_SYMBOL(bdi_unregister); +static void bdi_wb_init(struct bdi_writeback *wb, struct backing_dev_info *bdi) +{ + memset(wb, 0, sizeof(*wb)); + + wb->bdi = bdi; + wb->last_old_flush = jiffies; + INIT_LIST_HEAD(&wb->b_dirty); + INIT_LIST_HEAD(&wb->b_io); + INIT_LIST_HEAD(&wb->b_more_io); + setup_timer(&wb->wakeup_timer, wakeup_timer_fn, (unsigned long)bdi); +} + int bdi_init(struct backing_dev_info *bdi) { int i, err; |