[ovs-dev] [PATCH v5 net-next] MPLS: Use mpls_features to activate software MPLS GSO segmentation

[David Miller]

From: Simon Horman <horms at verge.net.au>
Date: Wed,  4 Jun 2014 08:53:17 +0900

> If an MPLS packet requires segmentation then use mpls_features
> to determine if the software implementation should be used.
> 
> As no driver advertises MPLS GSO segmentation this will always be
> the case.
> 
> I had not noticed that this was necessary before as software MPLS GSO
> segmentation was already being used in my test environment. I believe that
> the reason for that is the skbs in question always had fragments and the
> driver I used does not advertise NETIF_F_FRAGLIST (which seems to be the
> case for most drivers). Thus software segmentation was activated by
> skb_gso_ok().
> 
> This introduces the overhead of an extra call to skb_network_protocol()
> in the case where where CONFIG_NET_MPLS_GSO is set and
> skb->ip_summed == CHECKSUM_NONE.
> 
> Thanks to Jesse Gross for prompting me to investigate this.
> 
> Signed-off-by: Simon Horman <horms at verge.net.au>
> Acked-by: YAMAMOTO Takashi <yamamoto at valinux.co.jp>

Applied to net-next, thanks Simon.