Re: [RFC v2] mac80211: assign needed_headroom/tailroom for netdevs

David Miller
2008-05-05T19:50:13Z

From: Johannes Berg <johannes@sipsolutions.net>
Date: Mon, 05 May 2008 21:05:15 +0200

> On Mon, 2008-05-05 at 11:58 -0700, David Miller wrote:
> > From: Johannes Berg <johannes@sipsolutions.net>
> > Date: Mon, 05 May 2008 19:57:34 +0200
> >
> > > NETIF_F_FRAGLIST I haven't understood, but it seems to apply mostly for
> > > IP fragmentation?
> >
> > That's right. It's for cards that can do IP fragmentation in
> > hardware.
>
> What does "do IP fragmentation in hardware" mean?

My bad, it merely allows for devices that can handle
frag lists in sk_buff as transmit packets.

I guess you could use this, btw, to take on arbitrary things
to the front of frames to handle big headers. But that's more
expensive than just getting the LL header length right.