From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Michael S. Tsirkin" Subject: Re: [PATCH] virtio_net: enable big packets for large MTU values Date: Wed, 29 Mar 2017 19:13:33 +0300 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-Transfer-Encoding: 7bit Cc: netdev@vger.kernel.org, virtualization@lists.linux-foundation.org To: linux-kernel@vger.kernel.org Return-path: Content-Disposition: inline In-Reply-To: <1490791079-22108-1-git-send-email-mst@redhat.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: virtualization-bounces@lists.linux-foundation.org Errors-To: virtualization-bounces@lists.linux-foundation.org List-Id: netdev.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