Any chance this made it into 3.0.3?
It''d be really nice to be able to set MTU 9000 for some free
performance
improvements for iSCSI.
Thanks,
Dmitri
> -----Original Message-----
> From: xen-users-bounces@lists.xensource.com
> [mailto:xen-users-bounces@lists.xensource.com] On Behalf Of
> Daniele Palumbo
> Sent: Wednesday, September 13, 2006 10:55 AM
> To: xen-users@lists.xensource.com
> Cc: xen-devel
> Subject: Re: [Xen-users] Ethernet MTU
>
>
> I have some news...
>
> On Wednesday 16 August 2006 22:53, Dominique Rousseau wrote:
> > After some tries, it looks like the vif code don''t handle
> frames with
> > size larger than 1500.
>
> true:
> http://lists.xensource.com/archives/html/xen-devel/2006-08/msg
> 00944.html
>
> > Looking at the code, there is the following snippet that
> seems to be
> > the probleme (in drivers/xen/netback/netback.c) :
> >
> > if (unlikely(txreq.size < ETH_HLEN) ||
> > unlikely(txreq.size > ETH_FRAME_LEN)) {
> > DPRINTK("Bad packet size: %d\n",
txreq.size);
> > make_tx_response(netif, txreq.id,
> NETIF_RSP_ERROR);
> > netif_put(netif);
> > continue;
> > }
>
> ./include/linux/if_vlan.h:#define VLAN_ETH_FRAME_LEN 1518
> /* Max. octets
> in frame sans FCS */
> ./include/linux/if_ether.h:#define ETH_FRAME_LEN 1514
> /*
> Max. octets in frame sans FCS */
>
> ./include/linux/if_vlan.h:#define VLAN_ETH_HLEN 18
> /* Total
> octets in header. */
> ./include/linux/if_ether.h:#define ETH_HLEN 14
> /* Total
> octets in header. */
>
> netfront_vlan.patch:
> ---
> # Node ID a5ee1cb525bbe8954dc3332ceec951e09a378b68
> # parent: c097485037f7417b77db34da198b62a9c9481dc5
> Make MTU rx check in netfront more permissive to allow for
> 8021q vlan tagging.
>
> Signed-off-by: Keir Fraser <keir@xensource.com>
>
> --- a/linux-2.6-xen-sparse/drivers/xen/netfront/netfront.c
> Wed Mar 15
> 12:41:58 2006 +0100
> +++ b/linux-2.6-xen-sparse/drivers/xen/netfront/netfront.c
> Wed Mar 15
> 12:52:33 2006 +0100
> @@ -845,11 +845,11 @@ static int netif_poll(struct net_device
> }
>
> while ((skb = __skb_dequeue(&rxq)) != NULL) {
> - if (skb->len > (dev->mtu + ETH_HLEN)) {
> + if (skb->len > (dev->mtu + ETH_HLEN + 4)) {
> if (net_ratelimit())
> printk(KERN_INFO "Received
> packet too big
> for "
> "MTU (%d > %d)\n",
> - skb->len - ETH_HLEN,
dev->mtu);
> + skb->len - ETH_HLEN - 4,
> + dev->mtu);
> skb->len = 0;
> skb->tail = skb->data;
> init_skb_shinfo(skb);
> ---
>
> looking at all that things, maybe the solutions is to change
> ETH_FRAME_LEN in
> VLAN_ETH_FRAME_LEN...
> or to remove that check (already done in unstable).
>
> i''ll try tomorrow.
>
> bye
> d.
>
> _______________________________________________
> Xen-users mailing list
> Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
>
The information transmitted is intended only for the person or entity to which
it is addressed and may contain confidential and/or privileged material. Any
review, retransmission, dissemination or other use of, or taking of any action
in reliance upon, this information by persons or entities other than the
intended recipient is prohibited. If you received this in error, please contact
the sender and delete the material from any computer
_______________________________________________
Xen-users mailing list
Xen-users@lists.xensource.com
http://lists.xensource.com/xen-users