diff options
Diffstat (limited to 'fs/btrfs/async-thread.c')
| -rw-r--r-- | fs/btrfs/async-thread.c | 61 |
1 files changed, 53 insertions, 8 deletions
diff --git a/fs/btrfs/async-thread.c b/fs/btrfs/async-thread.c index 8e2fec05dbe0..c84ca1f5259a 100644 --- a/fs/btrfs/async-thread.c +++ b/fs/btrfs/async-thread.c @@ -16,11 +16,11 @@ * Boston, MA 021110-1307, USA. */ -#include <linux/version.h> #include <linux/kthread.h> #include <linux/list.h> #include <linux/spinlock.h> -# include <linux/freezer.h> +#include <linux/freezer.h> +#include <linux/ftrace.h> #include "async-thread.h" #define WORK_QUEUED_BIT 0 @@ -143,6 +143,7 @@ static int worker_loop(void *arg) struct btrfs_work *work; do { spin_lock_irq(&worker->lock); +again_locked: while (!list_empty(&worker->pending)) { cur = worker->pending.next; work = list_entry(cur, struct btrfs_work, list); @@ -165,14 +166,50 @@ static int worker_loop(void *arg) check_idle_worker(worker); } - worker->working = 0; if (freezing(current)) { + worker->working = 0; + spin_unlock_irq(&worker->lock); refrigerator(); } else { - set_current_state(TASK_INTERRUPTIBLE); spin_unlock_irq(&worker->lock); - if (!kthread_should_stop()) + if (!kthread_should_stop()) { + cpu_relax(); + /* + * we've dropped the lock, did someone else + * jump_in? + */ + smp_mb(); + if (!list_empty(&worker->pending)) + continue; + + /* + * this short schedule allows more work to + * come in without the queue functions + * needing to go through wake_up_process() + * + * worker->working is still 1, so nobody + * is going to try and wake us up + */ + schedule_timeout(1); + smp_mb(); + if (!list_empty(&worker->pending)) + continue; + + /* still no more work?, sleep for real */ + spin_lock_irq(&worker->lock); + set_current_state(TASK_INTERRUPTIBLE); + if (!list_empty(&worker->pending)) + goto again_locked; + + /* + * this makes sure we get a wakeup when someone + * adds something new to the queue + */ + worker->working = 0; + spin_unlock_irq(&worker->lock); + schedule(); + } __set_current_state(TASK_RUNNING); } } while (!kthread_should_stop()); @@ -350,13 +387,14 @@ int btrfs_requeue_work(struct btrfs_work *work) { struct btrfs_worker_thread *worker = work->worker; unsigned long flags; + int wake = 0; if (test_and_set_bit(WORK_QUEUED_BIT, &work->flags)) goto out; spin_lock_irqsave(&worker->lock, flags); - atomic_inc(&worker->num_pending); list_add_tail(&work->list, &worker->pending); + atomic_inc(&worker->num_pending); /* by definition we're busy, take ourselves off the idle * list @@ -368,10 +406,16 @@ int btrfs_requeue_work(struct btrfs_work *work) &worker->workers->worker_list); spin_unlock_irqrestore(&worker->workers->lock, flags); } + if (!worker->working) { + wake = 1; + worker->working = 1; + } spin_unlock_irqrestore(&worker->lock, flags); - + if (wake) + wake_up_process(worker->task); out: + return 0; } @@ -398,9 +442,10 @@ int btrfs_queue_worker(struct btrfs_workers *workers, struct btrfs_work *work) } spin_lock_irqsave(&worker->lock, flags); + + list_add_tail(&work->list, &worker->pending); atomic_inc(&worker->num_pending); check_busy_worker(worker); - list_add_tail(&work->list, &worker->pending); /* * avoid calling into wake_up_process if this thread has already |