From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753447AbdC2QNi (ORCPT ); Wed, 29 Mar 2017 12:13:38 -0400 Received: from mx1.redhat.com ([209.132.183.28]:13325 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752944AbdC2QNg (ORCPT ); Wed, 29 Mar 2017 12:13:36 -0400 DMARC-Filter: OpenDMARC Filter v1.3.2 mx1.redhat.com ECA667304C Authentication-Results: ext-mx10.extmail.prod.ext.phx2.redhat.com; dmarc=none (p=none dis=none) header.from=redhat.com Authentication-Results: ext-mx10.extmail.prod.ext.phx2.redhat.com; spf=pass smtp.mailfrom=mst@redhat.com DKIM-Filter: OpenDKIM Filter v2.11.0 mx1.redhat.com ECA667304C Date: Wed, 29 Mar 2017 19:13:33 +0300 From: "Michael S. Tsirkin" To: linux-kernel@vger.kernel.org Cc: Jason Wang , virtualization@lists.linux-foundation.org, netdev@vger.kernel.org Subject: Re: [PATCH] virtio_net: enable big packets for large MTU values Message-ID: <20170329191324-mutt-send-email-mst@kernel.org> References: <1490791079-22108-1-git-send-email-mst@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1490791079-22108-1-git-send-email-mst@redhat.com> X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.39]); Wed, 29 Mar 2017 16:13:35 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Mar 29, 2017 at 03:38:09PM +0300, Michael S. Tsirkin wrote: > If one enables e.g. jumbo frames without mergeable > buffers, packets won't fit in 1500 byte buffers > we use. Switch to big packet mode instead. > TODO: make sizing more exact, possibly extend small > packet mode to use larger pages. > > Signed-off-by: Michael S. Tsirkin Fixes: 14de9d114a82 ("virtio-net: Add initial MTU advice feature") > --- > drivers/net/virtio_net.c | 4 ++++ > 1 file changed, 4 insertions(+) > > diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c > index e0fb3707..9dc31dc 100644 > --- a/drivers/net/virtio_net.c > +++ b/drivers/net/virtio_net.c > @@ -2428,6 +2428,10 @@ static int virtnet_probe(struct virtio_device *vdev) > dev->mtu = mtu; > dev->max_mtu = mtu; > } > + > + /* TODO: size buffers correctly in this case. */ > + if (dev->mtu > ETH_DATA_LEN) > + vi->big_packets = true; > } > > if (vi->any_header_sg) > -- > MST