On Mon, 2013-07-22 at 19:38 +0100, Ben Hutchings wrote: > On Mon, 2013-07-22 at 11:29 -0700, Grant Grundler wrote: > > On Mon, Jul 22, 2013 at 10:07 AM, Eric Dumazet <eric.dumazet@xxxxxxxxx> wrote: > > ... > > > I guess that if a driver does not advertise NETIF_F_SG, this > > > skb_linearize() call is not needed : All frames reaching your xmit > > > function should already be linear > > > > As Ben Hutchings pointed out, hw_features is still setting this...but > > I'm not sure how that matters. > > > > ax88179_set_features() doesn't allow setting SG or TSO features. But > > I expect it would be "not too difficult" to add such that ethtool > > could set those features after boot. > [...] > > It already can. That's what putting feature flags in hw_features does. My original concern, that inspired this patch, was to remove SG support, as this driver does not have SG support at all. Linearize a full TSO packet needs order-5 allocations, thats likely to fail and lead to very slow TCP performance, because it will only rely on retransmits. -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
