From: Jason Wang <jasowang@redhat.com>
To: rusty@rustcorp.com.au, mst@redhat.com,
virtualization@lists.linux-foundation.org,
linux-kernel@vger.kernel.org, netdev@vger.kernel.org
Cc: davem@davemloft.net, eric.dumazet@gmail.com,
Jason Wang <jasowang@redhat.com>
Subject: [RFC PATCH net-next 2/6] virtio: introduce virtio_enable_cb_avail()
Date: Wed, 15 Oct 2014 15:25:26 +0800 [thread overview]
Message-ID: <1413357930-45302-3-git-send-email-jasowang@redhat.com> (raw)
In-Reply-To: <1413357930-45302-1-git-send-email-jasowang@redhat.com>
This patch introduces virtio_enable_cb_avail() to publish avail idx
and used event. This could be used by batched buffer submitting to
reduce the number of tx interrupts.
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
---
drivers/virtio/virtio_ring.c | 22 ++++++++++++++++++++--
include/linux/virtio.h | 2 ++
2 files changed, 22 insertions(+), 2 deletions(-)
diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c
index 1b3929f..d67fbf8 100644
--- a/drivers/virtio/virtio_ring.c
+++ b/drivers/virtio/virtio_ring.c
@@ -567,14 +567,32 @@ unsigned virtqueue_enable_cb_prepare(struct virtqueue *_vq)
* entry. Always do both to keep code simple. */
vq->vring.avail->flags &= ~VRING_AVAIL_F_NO_INTERRUPT;
/* Make sure used event never go backwards */
- if (!vring_need_event(vring_used_event(&vq->vring),
- vq->vring.avail->idx, last_used_idx))
+ if (vq->vring.avail->idx != vring_used_event(&vq->vring) &&
+ !vring_need_event(vring_used_event(&vq->vring),
+ vq->vring.avail->idx, last_used_idx)) {
vring_used_event(&vq->vring) = last_used_idx;
+ }
END_USE(vq);
return last_used_idx;
}
EXPORT_SYMBOL_GPL(virtqueue_enable_cb_prepare);
+bool virtqueue_enable_cb_avail(struct virtqueue *_vq)
+{
+ struct vring_virtqueue *vq = to_vvq(_vq);
+ bool ret;
+
+ START_USE(vq);
+ vq->vring.avail->flags &= ~VRING_AVAIL_F_NO_INTERRUPT;
+ vring_used_event(&vq->vring) = vq->vring.avail->idx;
+ ret = vring_need_event(vq->vring.avail->idx,
+ vq->last_used_idx, vq->vring.used->idx);
+ END_USE(vq);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(virtqueue_enable_cb_avail);
+
/**
* virtqueue_poll - query pending used buffers
* @vq: the struct virtqueue we're talking about.
diff --git a/include/linux/virtio.h b/include/linux/virtio.h
index b46671e..bfaf058 100644
--- a/include/linux/virtio.h
+++ b/include/linux/virtio.h
@@ -65,6 +65,8 @@ bool virtqueue_enable_cb(struct virtqueue *vq);
unsigned virtqueue_enable_cb_prepare(struct virtqueue *vq);
+bool virtqueue_enable_cb_avail(struct virtqueue *vq);
+
bool virtqueue_poll(struct virtqueue *vq, unsigned);
bool virtqueue_enable_cb_delayed(struct virtqueue *vq);
--
1.7.1
next prev parent reply other threads:[~2014-10-15 7:44 UTC|newest]
Thread overview: 36+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-10-15 7:25 [RFC PATCH net-next 0/6] Always use tx interrupt for virtio-net Jason Wang
2014-10-15 7:25 ` [RFC PATCH net-next 1/6] virtio: make sure used event never go backwards Jason Wang
2014-10-15 9:34 ` Michael S. Tsirkin
2014-10-15 10:13 ` Jason Wang
2014-10-15 10:32 ` Michael S. Tsirkin
2014-10-15 10:44 ` Jason Wang
2014-10-15 11:38 ` Michael S. Tsirkin
2014-10-17 5:04 ` Jason Wang
2014-10-15 7:25 ` Jason Wang [this message]
2014-10-15 9:28 ` [RFC PATCH net-next 2/6] virtio: introduce virtio_enable_cb_avail() Michael S. Tsirkin
2014-10-15 10:19 ` Jason Wang
2014-10-15 10:41 ` Michael S. Tsirkin
2014-10-15 10:58 ` Jason Wang
2014-10-15 11:43 ` Michael S. Tsirkin
2014-10-15 7:25 ` [RFC PATCH net-next 3/6] virtio-net: small optimization on free_old_xmit_skbs() Jason Wang
2014-10-15 9:36 ` Eric Dumazet
2014-10-15 9:37 ` Michael S. Tsirkin
2014-10-15 9:49 ` David Laight
2014-10-15 10:48 ` Michael S. Tsirkin
2014-10-15 10:51 ` David Laight
2014-10-15 12:00 ` Michael S. Tsirkin
2014-10-15 7:25 ` [RFC PATCH net-next 4/6] virtio-net: return the number of packets sent in free_old_xmit_skbs() Jason Wang
2014-10-15 7:25 ` [RFC PATCH net-next 5/6] virtio-net: enable tx interrupt Jason Wang
2014-10-15 9:37 ` Eric Dumazet
2014-10-15 10:21 ` Jason Wang
2014-10-15 10:18 ` Michael S. Tsirkin
2014-10-15 10:25 ` Jason Wang
2014-10-15 10:43 ` Michael S. Tsirkin
2014-10-15 11:00 ` Jason Wang
2014-10-15 7:25 ` [RFC PATCH net-next 6/6] virtio-net: enable tx interrupt only for the final skb in the chain Jason Wang
2014-10-15 10:22 ` Michael S. Tsirkin
2014-10-15 10:31 ` Jason Wang
2014-10-15 10:46 ` Michael S. Tsirkin
2014-10-15 10:25 ` [RFC PATCH net-next 0/6] Always use tx interrupt for virtio-net Michael S. Tsirkin
2014-10-15 11:14 ` Jason Wang
2014-10-15 11:58 ` Michael S. Tsirkin
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