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| author |   Jason Wang <jasowang@redhat.com> | 2016-03-04 06:24:51 -0500 |
|---|---|---|
| committer |   Michael S. Tsirkin <mst@redhat.com> | 2016-03-11 02:18:45 +0200 |
| commit | 526d3e7ff515582eaf7cf5d9da2a11bf681204e6 (patch) | |
| tree | 0f8cb97f616c8b09c1c8dd90530006581b26a3da /drivers/vhost | |
| parent | virtio_balloon: Allow to resize and update the balloon stats in parallel (diff) | |
| download | linux-dev-526d3e7ff515582eaf7cf5d9da2a11bf681204e6.tar.xz linux-dev-526d3e7ff515582eaf7cf5d9da2a11bf681204e6.zip | |
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>
Diffstat (limited to 'drivers/vhost')
| -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 328c54ab0154..596de212fe7e 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); |