On 12/08/2018 01:57 AM, Florian Westphal wrote:
> Jesper Dangaard Brouer <bro...@redhat.com> wrote:
>> From: Ilias Apalodimas <ilias.apalodi...@linaro.org>
>>
>> This patch is changing struct sk_buff, and is thus per-definition
>> controversial.
>>
>> Place a new member 'mem_info' of type struct xdp_mem_info, just after
>> members (flags) head_frag and pfmemalloc, And not in between
>> headers_start/end to ensure skb_copy() and pskb_copy() work as-is.
>> Copying mem_info during skb_clone() is required. This makes sure that
>> pages are correctly freed or recycled during the altered
>> skb_free_head() invocation.
>
> I read this to mean that this 'info' isn't accessed/needed until skb
> is freed. Any reason its not added at the end?
>
> This would avoid moving other fields that are probably accessed
> more frequently during processing.
>
But I do not get why the patch is needed.
Adding extra cost for each skb destruction is costly.
I though XDP was all about _not_ having skbs.
Please let's do not slow down the non XDP stack only to make XDP more appealing.
