Re: [RFC PATCH 9/9] ixgbe/ixgbevf: Add support for GSO partial

On Fri, Mar 18, 2016 at 7:05 PM, Jesse Gross [off-list ref] wrote:

On Fri, Mar 18, 2016 at 4:25 PM, Alexander Duyck [off-list ref] wrote:

quoted

This patch adds support for partial GSO segmentation in the case of GRE or
UDP encapsulated frames.

The one bit in this patch that is a bit controversial is the fact that we
are leaving the inner IPv4 IP ID as a static value in the case of
segmentation.  As per RFC6864 this should be acceptable as TCP frames set
the DF bit so the IP ID should be ignored.  However this is not always the
case as header compression schemes for PPP and SLIP can end up taking a
performance hit as they have to record the fact that the ID didn't change
as expected.

In addition GRO was examining the IP ID field as well.  As such on older
GRO implementations TSO frames from this driver may end up blocking GRO on
the other end which will likely hurt performance instead of helping it.

Signed-off-by: Alexander Duyck <redacted>

I wasn't able to apply this patch, it seems like it might be based on
some Intel driver patches that haven't been merged into net-next yet?

Yeah, I based it off of Jeff's Kirshers dev-queue branch of his
next-queue git repo.  Odds are it isn't working because net-next still
doesn't have the HW_CSUM patches I submitted a couple months ago.  I
ended up doing that as I needed to pull in that and a couple of other
fixes for i40e in order to apply the patches for those two drivers.

- Alex