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Groups > linux.kernel > #1517801
| From | Jason Wang <jasowang@redhat.com> |
|---|---|
| Newsgroups | linux.kernel |
| Subject | [PATCH 3/3] vhost_net: tx support batching |
| Date | 2016-11-09 08:40 +0100 |
| Message-ID | <sBvEd-4gF-11@gated-at.bofh.it> (permalink) |
| References | <sBvEd-4gF-3@gated-at.bofh.it> |
| Organization | linux.* mail to news gateway |
This patch tries to utilize tuntap rx batching by peeking the tx
virtqueue during transmission, if there's more available buffers in
the virtqueue, set MSG_MORE flag for a hint for tuntap to batch the
packets. The maximum number of batched tx packets were specified
through a module parameter: tx_bached.
When use 16 as tx_batched:
Pktgen test shows 16% on tx pps in guest.
Netperf test does not show obvious regression.
For safety, 1 were used as the default value for tx_batched.
Signed-off-by: Jason Wang <jasowang@redhat.com>
---
drivers/vhost/net.c | 15 ++++++++++++++-
drivers/vhost/vhost.c | 1 +
drivers/vhost/vhost.h | 1 +
3 files changed, 16 insertions(+), 1 deletion(-)
diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c
index 5dc128a..51c378e 100644
--- a/drivers/vhost/net.c
+++ b/drivers/vhost/net.c
@@ -35,6 +35,10 @@ module_param(experimental_zcopytx, int, 0444);
MODULE_PARM_DESC(experimental_zcopytx, "Enable Zero Copy TX;"
" 1 -Enable; 0 - Disable");
+static int tx_batched = 1;
+module_param(tx_batched, int, 0444);
+MODULE_PARM_DESC(tx_batched, "Number of patches batched in TX");
+
/* Max number of bytes transferred before requeueing the job.
* Using this limit prevents one virtqueue from starving others. */
#define VHOST_NET_WEIGHT 0x80000
@@ -454,6 +458,16 @@ static void handle_tx(struct vhost_net *net)
msg.msg_control = NULL;
ubufs = NULL;
}
+ total_len += len;
+ if (vq->delayed < tx_batched &&
+ total_len < VHOST_NET_WEIGHT &&
+ !vhost_vq_avail_empty(&net->dev, vq)) {
+ vq->delayed++;
+ msg.msg_flags |= MSG_MORE;
+ } else {
+ vq->delayed = 0;
+ msg.msg_flags &= ~MSG_MORE;
+ }
/* TODO: Check specific error and bomb out unless ENOBUFS? */
err = sock->ops->sendmsg(sock, &msg, len);
if (unlikely(err < 0)) {
@@ -472,7 +486,6 @@ static void handle_tx(struct vhost_net *net)
vhost_add_used_and_signal(&net->dev, vq, head, 0);
else
vhost_zerocopy_signal_used(net, vq);
- total_len += len;
vhost_net_tx_packet(net);
if (unlikely(total_len >= VHOST_NET_WEIGHT)) {
vhost_poll_queue(&vq->poll);
diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c
index fdf4cdf..bc362c7 100644
--- a/drivers/vhost/vhost.c
+++ b/drivers/vhost/vhost.c
@@ -311,6 +311,7 @@ static void vhost_vq_reset(struct vhost_dev *dev,
vq->busyloop_timeout = 0;
vq->umem = NULL;
vq->iotlb = NULL;
+ vq->delayed = 0;
}
static int vhost_worker(void *data)
diff --git a/drivers/vhost/vhost.h b/drivers/vhost/vhost.h
index 78f3c5f..9f81a94 100644
--- a/drivers/vhost/vhost.h
+++ b/drivers/vhost/vhost.h
@@ -141,6 +141,7 @@ struct vhost_virtqueue {
bool user_be;
#endif
u32 busyloop_timeout;
+ int delayed;
};
struct vhost_msg_node {
--
2.7.4
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[PATCH 1/3] tuntap: rx batching Jason Wang <jasowang@redhat.com> - 2016-11-09 08:40 +0100
[PATCH 3/3] vhost_net: tx support batching Jason Wang <jasowang@redhat.com> - 2016-11-09 08:40 +0100
Re: [PATCH 3/3] vhost_net: tx support batching "Michael S. Tsirkin" <mst@redhat.com> - 2016-11-09 21:10 +0100
Re: [PATCH 3/3] vhost_net: tx support batching Jason Wang <jasowang@redhat.com> - 2016-11-11 03:30 +0100
[PATCH 2/3] vhost: better detection of available buffers Jason Wang <jasowang@redhat.com> - 2016-11-09 08:40 +0100
Re: [PATCH 2/3] vhost: better detection of available buffers "Michael S. Tsirkin" <mst@redhat.com> - 2016-11-09 21:00 +0100
Re: [PATCH 2/3] vhost: better detection of available buffers Jason Wang <jasowang@redhat.com> - 2016-11-11 03:20 +0100
Re: [PATCH 2/3] vhost: better detection of available buffers "Michael S. Tsirkin" <mst@redhat.com> - 2016-11-11 04:50 +0100
Re: [PATCH 2/3] vhost: better detection of available buffers Jason Wang <jasowang@redhat.com> - 2016-11-11 05:20 +0100
Re: [PATCH 2/3] vhost: better detection of available buffers "Michael S. Tsirkin" <mst@redhat.com> - 2016-11-11 17:30 +0100
Re: [PATCH 1/3] tuntap: rx batching "Michael S. Tsirkin" <mst@redhat.com> - 2016-11-09 17:40 +0100
Re: [PATCH 1/3] tuntap: rx batching Jason Wang <jasowang@redhat.com> - 2016-11-11 03:10 +0100
Re: [PATCH 1/3] tuntap: rx batching "Michael S. Tsirkin" <mst@redhat.com> - 2016-11-11 04:40 +0100
Re: [PATCH 1/3] tuntap: rx batching John Fastabend <john.fastabend@gmail.com> - 2016-11-11 05:20 +0100
Re: [PATCH 1/3] tuntap: rx batching Jason Wang <jasowang@redhat.com> - 2016-11-11 05:30 +0100
Re: [PATCH 1/3] tuntap: rx batching John Fastabend <john.fastabend@gmail.com> - 2016-11-11 05:50 +0100
Re: [PATCH 1/3] tuntap: rx batching "Michael S. Tsirkin" <mst@redhat.com> - 2016-11-11 17:30 +0100
Re: [PATCH 1/3] tuntap: rx batching Jason Wang <jasowang@redhat.com> - 2016-11-11 05:20 +0100
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