[Xen-devel] "tcp: refine TSO autosizing" causes performance regression on Xen

[Eric Dumazet]

On Thu, 2015-04-16 at 12:20 +0800, Herbert Xu wrote:
> Eric Dumazet <eric.dumazet at gmail.com> wrote:
> >
> > We already have netdev->gso_max_size and netdev->gso_max_segs
> > which are cached into sk->sk_gso_max_size & sk->sk_gso_max_segs
> 
> It is quite dangerous to attempt tricks like this because a
> tc redirection or netfilter nat could change the destination
> device rendering such hints incorrect.

Right but we are talking of performance hints, on quite basic VM setup.

Here the guest would use xen and this hint would apply.