Re: [net-next,v4] openvswitch: Add packet len info to upcall.

On Mon, Jun 20, 2016 at 7:26 AM, William Tu [off-list ref] wrote:

The commit f2a4d086ed4c ("openvswitch: Add packet truncation support.")
introduces packet truncation before sending to userspace upcall receiver.
This patch passes up the skb->len before truncation so that the upcall
receiver knows the original packet size. Potentially this will be used
by sFlow, where OVS translates sFlow config header=N to a sample action,
truncating packet to N byte in kernel datapath. Thus, only N bytes instead
of full-packet size is copied from kernel to userspace, saving the
kernel-to-userspace bandwidth.

Signed-off-by: William Tu <redacted>
Cc: Pravin Shelar <redacted>
---
v3->v4:
- Add OVS_PACKET_ATTR_LEN only when packet is truncated,
  This avoid sending extra attribute in the case of miss flow.
v2->v3:
- Remove platform specific name.
- Fix issue when receiving GSO packet
- Remove skblen in struct dp_upcall_info
v1->v2:
- Pass skb->len to userspace instead of cutlen
---

Acked-by: Pravin B Shelar <redacted>

Thanks.