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Btrfs: Clear the device->running_pending flag before bailing on congestion

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Btrfs maintains a queue of async bio submissions so the checksumming
threads don't have to wait on get_request_wait.  In order to avoid
extra wakeups, this code has a running_pending flag that is used
to tell new submissions they don't need to wake the thread.

When the threads notice congestion on a single device, they
may decide to requeue the job and move on to other devices.  This
makes sure the running_pending flag is cleared before the
job is requeued.

It should help avoid IO stalls by making sure the task is woken up
when new submissions come in.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
This commit is contained in:
Chris Mason
2009-01-16 11:58:19 -05:00
parent e293e97e36
commit 1d9e2ae949
1 changed files with 1 additions and 0 deletions
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fs/btrfs/volumes.c
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@@ -220,6 +220,7 @@ loop:
tail->bi_next = old_head; tail->bi_next = old_head;
else else
device->pending_bio_tail = tail; device->pending_bio_tail = tail;
device->running_pending = 0;
spin_unlock(&device->io_lock); spin_unlock(&device->io_lock);
btrfs_requeue_work(&device->work); btrfs_requeue_work(&device->work);