This path introduces a helper which can give a hint for whether or not there's a work queued in the work list.
Signed-off-by: Jason Wang <jasow...@redhat.com> --- drivers/vhost/vhost.c | 7 +++++++ drivers/vhost/vhost.h | 1 + 2 files changed, 8 insertions(+) diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c index eec2f11..163b365 100644 --- a/drivers/vhost/vhost.c +++ b/drivers/vhost/vhost.c @@ -245,6 +245,13 @@ 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 4772862..ea0327d 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); -- 1.8.3.1 _______________________________________________ Virtualization mailing list Virtualization@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/virtualization