[net-next,V2] vhost_net: conditionally enable tx polling
diff mbox series

Message ID 1510544734-6142-1-git-send-email-jasowang@redhat.com
State New, archived
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Series
  • [net-next,V2] vhost_net: conditionally enable tx polling
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Commit Message

Jason Wang Nov. 13, 2017, 3:45 a.m. UTC
We always poll tx for socket, this is sub optimal since this will
slightly increase the waitqueue traversing time and more important,
vhost could not benefit from commit 9e641bdcfa4e ("net-tun:
restructure tun_do_read for better sleep/wakeup efficiency") even if
we've stopped rx polling during handle_rx(), tx poll were still left
in the waitqueue.

Pktgen from a remote host to VM over mlx4 on two 2.00GHz Xeon E5-2650
shows 11.7% improvements on rx PPS. (from 1.28Mpps to 1.44Mpps)

Cc: Wei Xu <wexu@redhat.com>
Cc: Matthew Rosato <mjrosato@linux.vnet.ibm.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
---
Changes from V1:
- don't try to disable tx polling during start
- poll tx on error unconditonally
---
 drivers/vhost/net.c | 2 ++
 1 file changed, 2 insertions(+)

Patch
diff mbox series

diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c
index 68677d9..8d626d7 100644
--- a/drivers/vhost/net.c
+++ b/drivers/vhost/net.c
@@ -471,6 +471,7 @@  static void handle_tx(struct vhost_net *net)
 		goto out;
 
 	vhost_disable_notify(&net->dev, vq);
+	vhost_net_disable_vq(net, vq);
 
 	hdr_size = nvq->vhost_hlen;
 	zcopy = nvq->ubufs;
@@ -556,6 +557,7 @@  static void handle_tx(struct vhost_net *net)
 					% UIO_MAXIOV;
 			}
 			vhost_discard_vq_desc(vq, 1);
+			vhost_net_enable_vq(net, vq);
 			break;
 		}
 		if (err != len)