From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751805AbdKMDpn (ORCPT ); Sun, 12 Nov 2017 22:45:43 -0500 Received: from mx1.redhat.com ([209.132.183.28]:51208 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751349AbdKMDpm (ORCPT ); Sun, 12 Nov 2017 22:45:42 -0500 From: Jason Wang 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 , Matthew Rosato Subject: [PATCH net-next V2] vhost_net: conditionally enable tx polling Date: Mon, 13 Nov 2017 11:45:34 +0800 Message-Id: <1510544734-6142-1-git-send-email-jasowang@redhat.com> X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.27]); Mon, 13 Nov 2017 03:45:42 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 Cc: Matthew Rosato Signed-off-by: Jason Wang --- 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