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authorChris Mason <chris.mason@oracle.com>2009-08-05 16:36:45 -0400
committerChris Mason <chris.mason@oracle.com>2009-09-11 13:31:04 -0400
commit4e3f9c5042b43301d70781aee4a164a20878066b (patch)
treeb2ace00c27553ec2a10958e17d6b90ea264d5886
parent40431d6c1288793a682fc6f5e5b5c9d5cac34608 (diff)
downloadop-kernel-dev-4e3f9c5042b43301d70781aee4a164a20878066b.zip
op-kernel-dev-4e3f9c5042b43301d70781aee4a164a20878066b.tar.gz
Btrfs: keep irqs on more often in the worker threads
The btrfs worker thread spinlock was being used both for the queueing of IO and for the processing of ordered events. The ordered events never happen from end_io handlers, and so they don't need to use the _irq version of spinlocks. This adds a dedicated lock to the ordered lists so they don't have to run with irqs off. Signed-off-by: Chris Mason <chris.mason@oracle.com>
-rw-r--r--fs/btrfs/async-thread.c23
-rw-r--r--fs/btrfs/async-thread.h3
2 files changed, 16 insertions, 10 deletions
diff --git a/fs/btrfs/async-thread.c b/fs/btrfs/async-thread.c
index f10c895..4b4372d 100644
--- a/fs/btrfs/async-thread.c
+++ b/fs/btrfs/async-thread.c
@@ -124,14 +124,12 @@ out:
static noinline int run_ordered_completions(struct btrfs_workers *workers,
struct btrfs_work *work)
{
- unsigned long flags;
-
if (!workers->ordered)
return 0;
set_bit(WORK_DONE_BIT, &work->flags);
- spin_lock_irqsave(&workers->lock, flags);
+ spin_lock(&workers->order_lock);
while (1) {
if (!list_empty(&workers->prio_order_list)) {
@@ -154,17 +152,17 @@ static noinline int run_ordered_completions(struct btrfs_workers *workers,
if (test_and_set_bit(WORK_ORDER_DONE_BIT, &work->flags))
break;
- spin_unlock_irqrestore(&workers->lock, flags);
+ spin_unlock(&workers->order_lock);
work->ordered_func(work);
/* now take the lock again and call the freeing code */
- spin_lock_irqsave(&workers->lock, flags);
+ spin_lock(&workers->order_lock);
list_del(&work->order_list);
work->ordered_free(work);
}
- spin_unlock_irqrestore(&workers->lock, flags);
+ spin_unlock(&workers->order_lock);
return 0;
}
@@ -345,6 +343,7 @@ void btrfs_init_workers(struct btrfs_workers *workers, char *name, int max)
INIT_LIST_HEAD(&workers->order_list);
INIT_LIST_HEAD(&workers->prio_order_list);
spin_lock_init(&workers->lock);
+ spin_lock_init(&workers->order_lock);
workers->max_workers = max;
workers->idle_thresh = 32;
workers->name = name;
@@ -374,6 +373,7 @@ int btrfs_start_workers(struct btrfs_workers *workers, int num_workers)
INIT_LIST_HEAD(&worker->prio_pending);
INIT_LIST_HEAD(&worker->worker_list);
spin_lock_init(&worker->lock);
+
atomic_set(&worker->num_pending, 0);
atomic_set(&worker->refs, 1);
worker->workers = workers;
@@ -453,10 +453,8 @@ static struct btrfs_worker_thread *find_worker(struct btrfs_workers *workers)
again:
spin_lock_irqsave(&workers->lock, flags);
worker = next_worker(workers);
- spin_unlock_irqrestore(&workers->lock, flags);
if (!worker) {
- spin_lock_irqsave(&workers->lock, flags);
if (workers->num_workers >= workers->max_workers) {
goto fallback;
} else if (workers->atomic_worker_start) {
@@ -469,6 +467,7 @@ again:
goto again;
}
}
+ spin_unlock_irqrestore(&workers->lock, flags);
return worker;
fallback:
@@ -552,14 +551,18 @@ int btrfs_queue_worker(struct btrfs_workers *workers, struct btrfs_work *work)
worker = find_worker(workers);
if (workers->ordered) {
- spin_lock_irqsave(&workers->lock, flags);
+ /*
+ * you're not allowed to do ordered queues from an
+ * interrupt handler
+ */
+ spin_lock(&workers->order_lock);
if (test_bit(WORK_HIGH_PRIO_BIT, &work->flags)) {
list_add_tail(&work->order_list,
&workers->prio_order_list);
} else {
list_add_tail(&work->order_list, &workers->order_list);
}
- spin_unlock_irqrestore(&workers->lock, flags);
+ spin_unlock(&workers->order_lock);
} else {
INIT_LIST_HEAD(&work->order_list);
}
diff --git a/fs/btrfs/async-thread.h b/fs/btrfs/async-thread.h
index a562ad8..fc089b9 100644
--- a/fs/btrfs/async-thread.h
+++ b/fs/btrfs/async-thread.h
@@ -99,6 +99,9 @@ struct btrfs_workers {
/* lock for finding the next worker thread to queue on */
spinlock_t lock;
+ /* lock for the ordered lists */
+ spinlock_t order_lock;
+
/* extra name for this worker, used for current->name */
char *name;
};
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