On Mon, Aug 29, 2016 at 12:22:37PM -0700, Eric Dumazet wrote: > On Mon, 2016-08-29 at 15:51 -0300, Marcelo Ricardo Leitner wrote: > > skb->truesize = SKB_TRUESIZE(skb_end_offset(skb)); > > > > Shouldn't __pskb_pull_tail() already fix this? As it seems the expected > > behavior and it would have a more global effect then. For drivers not > > using copybreak, that's needed here anyway, but maybe this help other > > protocols/situations too. > > That would be difficult, because some callers do their own truesize > tacking (skb might be attached/charged to a socket, so changing > skb->truesize would need to adjust the amount that was charged) > > This is why pskb_expand_head() is not allowed to mess with skb->truesize > (but in the opposite way, since we probably are increasing > skb->truesize) >
Ok, makes sense. > Not sure it is worth the pain in fast path, where packets are consumed > so fast that their skb->truesize being slightly over estimated is not an > issue. Good point, thanks.
