On Mon, 2017-08-14 at 18:19 +0200, Jesper Dangaard Brouer wrote:
> The output (extracted below) didn't show who called 'do_raw_spin_lock',
> BUT it showed another interesting thing. The kernel code
> __dev_queue_xmit() in might create route dst-cache problem for itself(?),
> as it will first call skb_dst_force() and then skb_dst_drop() when the
> packet is transmitted on a VLAN.
>
> static int __dev_queue_xmit(struct sk_buff *skb, void *accel_priv)
> {
> [...]
> /* If device/qdisc don't need skb->dst, release it right now while
> * its hot in this cpu cache.
> */
> if (dev->priv_flags & IFF_XMIT_DST_RELEASE)
> skb_dst_drop(skb);
> else
> skb_dst_force(skb);
This is explained in this commit changelog.
https://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next.git/commit/?id=93f154b594fe47e4a7e5358b309add449a046cd3
