From: Jason Wang <jasowang@redhat.com>
To: mst@redhat.com, jasowang@redhat.com, kvm@vger.kernel.org,
virtualization@lists.linux-foundation.org,
netdev@vger.kernel.org, linux-kernel@vger.kernel.org
Cc: Wei Xu <wexu@redhat.com>, Matthew Rosato <mjrosato@linux.vnet.ibm.com>
Subject: [PATCH net-next V2] vhost_net: conditionally enable tx polling
Date: Mon, 13 Nov 2017 11:45:34 +0800 [thread overview]
Message-ID: <1510544734-6142-1-git-send-email-jasowang@redhat.com> (raw)
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(+)
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)
--
2.7.4
reply other threads:[~2017-11-13 3:45 UTC|newest]
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