[RFC V7 PATCH 2/7] virtio_ring: try to disable event index callbacks in virtqueue_disable_cb()
From: Jason Wang <jasowang@redhat.com>
Date: 2015-05-25 05:24:23
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Subsystem:
the rest, virtio core · Maintainers:
Linus Torvalds, "Michael S. Tsirkin", Jason Wang
Currently, we do nothing to prevent the callbacks in virtqueue_disable_cb() when event index is used. This may cause spurious interrupts which may damage the performance. This patch tries to publish last_used_idx as the used even to prevent the callbacks. Signed-off-by: Jason Wang <jasowang@redhat.com> --- drivers/virtio/virtio_ring.c | 1 + 1 file changed, 1 insertion(+)
diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c
index 096b857..a83aebc 100644
--- a/drivers/virtio/virtio_ring.c
+++ b/drivers/virtio/virtio_ring.c@@ -538,6 +538,7 @@ void virtqueue_disable_cb(struct virtqueue *_vq) struct vring_virtqueue *vq = to_vvq(_vq); vq->vring.avail->flags |= cpu_to_virtio16(_vq->vdev, VRING_AVAIL_F_NO_INTERRUPT); + vring_used_event(&vq->vring) = cpu_to_virtio16(_vq->vdev, vq->last_used_idx); } EXPORT_SYMBOL_GPL(virtqueue_disable_cb);
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1.8.3.1