在 2022/9/1 13:54, Guo Zhi 写道:
Vsock uses buffers in order, and for tx driver doesn't have to
know the length of the buffer. So we can do a batch for vsock if
in order negotiated, only write one used ring for a batch of buffers
Signed-off-by: Guo Zhi <qtxuning1...@sjtu.edu.cn>
---
drivers/vhost/vsock.c | 12 ++++++++++--
1 file changed, 10 insertions(+), 2 deletions(-)
diff --git a/drivers/vhost/vsock.c b/drivers/vhost/vsock.c
index 368330417bde..e08fbbb5439e 100644
--- a/drivers/vhost/vsock.c
+++ b/drivers/vhost/vsock.c
@@ -497,7 +497,7 @@ static void vhost_vsock_handle_tx_kick(struct vhost_work
*work)
struct vhost_vsock *vsock = container_of(vq->dev, struct vhost_vsock,
dev);
struct virtio_vsock_pkt *pkt;
- int head, pkts = 0, total_len = 0;
+ int head, pkts = 0, total_len = 0, add = 0;
unsigned int out, in;
bool added = false;
@@ -551,10 +551,18 @@ static void vhost_vsock_handle_tx_kick(struct vhost_work *work)
else
virtio_transport_free_pkt(pkt);
- vhost_add_used(vq, head, 0);
+ if (!vhost_has_feature(vq, VIRTIO_F_IN_ORDER)) {
+ vhost_add_used(vq, head, 0);
I'd do this step by step.
1) switch to use vhost_add_used_n() for vsock, less copy_to_user()
better performance
2) do in-order on top
+ } else {
+ vq->heads[add].id = head;
+ vq->heads[add++].len = 0;
How can we guarantee that we are in the boundary of the heads array?
Btw in the case of in-order we don't need to record the heads, instead
we just need to know the head of the last buffer, it reduces the stress
on the cache.
Thanks
+ }
added = true;
} while(likely(!vhost_exceeds_weight(vq, ++pkts, total_len)));
+ /* If in order feature negotiaged, we can do a batch to increase performance */
+ if (vhost_has_feature(vq, VIRTIO_F_IN_ORDER) && added)
+ vhost_add_used_n(vq, vq->heads, add);
no_more_replies:
if (added)
vhost_signal(&vsock->dev, vq);
_______________________________________________
Virtualization mailing list
Virtualization@lists.linux-foundation.org
https://lists.linuxfoundation.org/mailman/listinfo/virtualization
