Re: [RFC v2 00/10] HFI Virtual Network Interface Controller (VNIC)

On Mon, Jan 09, 2017 at 07:39:54PM -0800, Vishwanathapura, Niranjana wrote:

On Mon, Jan 09, 2017 at 09:51:04AM +0200, Leon Romanovsky wrote:

quoted

On Thu, Dec 15, 2016 at 11:28:06AM -0500, Doug Ledford wrote:

quoted

On 12/15/2016 9:52 AM, ira.weiny wrote:

2) With more than 60% of the code being MAD related, and another
significant chunk being hfi related, and only a minor bit (20% maybe?)
being net related,

Hi Doug and Ira,

I may admit that I didn't read the code very deep, but from brief
overview, I didn't find support for the claim the "60% code is MAD related".
It looks like the opposite thing will be more accurate.

Can you help me to understand this claim? How did you come to this
conclusion?

Thanks

Hi Leon,

Here is the breakdown of patches based on functionality.

Hi Niranjana,
Thank you for breakdown, it helped a lot.

In this series, patches #3..#8 compose hfi_vnic driver. In that, patches #4,
#7 and #8 are MAD focused (interfacing with MAD agent and handling MAD
packets).

Patch #3 is net device with all goodies from net stack.
https://patchwork.kernel.org/patch/9475639/
Patch #4 has one IB MAD related struct, all other things are specific to
OFA and HFI declarations.
https://patchwork.kernel.org/patch/9475653/
Patch #7 continues to implement agnostic to IB MAD net device.
https://patchwork.kernel.org/patch/9475641/
Patch #8 is without doubts, MAD related.
https://patchwork.kernel.org/patch/9475651/

Let's put aside patch #8, in such case, the proposed code won't need IB/core at
all and will look exactly like many other net drivers which encapsulate/decapsulate
packets.

Patch #6 and half of #3 (_encap.c/h) are OPA encapsulation related. Patch #5
is netdev statistic related (which includes statistics MAD definitions).
So, only part of patch #3 (_netdev.c and _ethtool.c) deals with interfacing
with netstack.
Those percentage numbers are based on actual lines of code in these patches
(files).

We are also looking into Jason’s suggestion to make hfi_vnic interface to
the bottom driver a generic interface. This will include moving some of the
netstack interfacing to the bottom hfi1 driver.

Great, do you have rough estimation when will it be posted on the ML?

Thanks

Niranjana