Re: [PATCH net-next 1/6] net: skbuff: don't use union for napi_id and sender_cpu

From: Eric Dumazet
Date: Thu Mar 31 2016 - 22:55:33 EST

On Fri, 2016-04-01 at 10:13 +0800, Jason Wang wrote:

> The problem is we want to support busy polling for tun. This needs
> napi_id to be passed to tun socket by sk_mark_napi_id() during
> tun_net_xmit(). But before reaching this, XPS will set sender_cpu will
> make us can't see correct napi_id.

Looks like napi_id should have precedence then ?

Only forwarding should allow the field to be cleared to allow XPS to do
its job.

Maybe skb_sender_cpu_clear() was removed too early (commit

Look, it is 8pm here, I am pretty sure a solution can be found,
but I am also need to take a break, I started at 3am today...