Hi,
On Fri, 2017-07-21 at 17:20 +0200, John Crispin wrote:
> In order to make HW flow offloading work in latest MediaTek silicon we need
> to propagate part of the RX DMS descriptor to the upper layers populating
> the flow offload engines HW tables. This patch adds an extra element to
> struct skb_shared_info allowing the ethernet drivers RX napi code to store
> the required information and make it persistent for the lifecycle of the
> skb and its clones.
>
> Signed-off-by: John Crispin <j...@phrozen.org>
> ---
> include/linux/skbuff.h | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
> index 4093552be1de..db9576cd946b 100644
> --- a/include/linux/skbuff.h
> +++ b/include/linux/skbuff.h
> @@ -426,6 +426,7 @@ struct skb_shared_info {
> unsigned int gso_type;
> u32 tskey;
> __be32 ip6_frag_id;
> + u32 dma_desc;
>
> /*
> * Warning : all fields before dataref are cleared in __alloc_skb()
This will increase the skb_shared_info struct size, which is already
quite large, and can have several kind of performance drawback.
AFAIK this is discouraged.
I don't understand the use case; the driver will set this field, but
who is going to consume it?
Thanks,
Paolo
