Subject: Re: [PATCH net-next] net: netdev_alloc_skb() use build_skb()

From: "Michael S. Tsirkin" <[email-masked]>
Date: Tue, 5 Jun 2012 00:20:50 +0300

On Mon, Jun 04, 2012 at 09:56:52PM +0200, Eric Dumazet wrote:
> On Mon, 2012-06-04 at 22:48 +0300, Michael S. Tsirkin wrote:
> 
> > If I do this what will truesize be? 128, no?
> 
> My example was not correct, since you must have enough room for the
> SKB_DATA_ALIGN(sizeof(struct skb_shared_info))  ( 320 bytes )
> 
> So it would be 128 + 320 = 448
> 

Ugh. I forgot about that. shinfo goes into the same page,
so we'll have to also make all frags shorter by 320
to leave space for shinfo at tail.
overall looks like we need hyprevisor extensions if
we want to use build_skb ...