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| author | Jason Wang <jasowang@redhat.com> | 2016-03-04 06:24:51 -0500 |
|---|---|---|
| committer | Alistair Strachan <astrachan@google.com> | 2019-05-14 17:56:52 -0700 |
| commit | eb7e61ae8c0aa8b1e9d3e36a055785da096d0f0e (patch) | |
| tree | 90622f58a1af9f7702adffe14fa6a172f72e8b53 | |
| parent | ea4e49b0dff9cacd52db01dbef9dd7e1ae4bb858 (diff) | |
UPSTREAM: vhost: introduce vhost_has_work()
This path introduces a helper which can give a hint for whether or not
there's a work queued in the work list. This could be used for busy
polling code to exit the busy loop.
Signed-off-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
(cherry picked from commit 526d3e7ff515582eaf7cf5d9da2a11bf681204e6)
Bug: 121166534
Test: Ran cuttlefish with android-4.4 + VSOCKETS, VMWARE_VMCI_VSOCKETS
Signed-off-by: Alistair Strachan <astrachan@google.com>
Change-Id: I2717a212f888b0d3ea78f1ce0bcc21ec9dee5050
| -rw-r--r-- | drivers/vhost/vhost.c | 7 | ||||
| -rw-r--r-- | drivers/vhost/vhost.h | 1 |
2 files changed, 8 insertions, 0 deletions
diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c index 167a263dfb86..65a1d2da114a 100644 --- a/drivers/vhost/vhost.c +++ b/drivers/vhost/vhost.c @@ -263,6 +263,13 @@ void vhost_work_queue(struct vhost_dev *dev, struct vhost_work *work) } EXPORT_SYMBOL_GPL(vhost_work_queue); +/* A lockless hint for busy polling code to exit the loop */ +bool vhost_has_work(struct vhost_dev *dev) +{ + return !list_empty(&dev->work_list); +} +EXPORT_SYMBOL_GPL(vhost_has_work); + void vhost_poll_queue(struct vhost_poll *poll) { vhost_work_queue(poll->dev, &poll->work); diff --git a/drivers/vhost/vhost.h b/drivers/vhost/vhost.h index 8f0dd0d915d4..eef33b11a7ed 100644 --- a/drivers/vhost/vhost.h +++ b/drivers/vhost/vhost.h @@ -37,6 +37,7 @@ struct vhost_poll { void vhost_work_init(struct vhost_work *work, vhost_work_fn_t fn); void vhost_work_queue(struct vhost_dev *dev, struct vhost_work *work); +bool vhost_has_work(struct vhost_dev *dev); void vhost_poll_init(struct vhost_poll *poll, vhost_work_fn_t fn, unsigned long mask, struct vhost_dev *dev); |