Re: [Intel-wired-lan] [RFC PATCH v3 0/6] Configuring traffic classes via new hardware offload mechanism in tc/mqprio

On 9/7/2017 9:45 AM, Shannon Nelson wrote:

On 9/7/2017 4:00 AM, Amritha Nambiar wrote:

quoted

The following series introduces a new hardware offload mode in
tc/mqprio where the TCs, the queue configurations and
bandwidth rate limits are offloaded to the hardware. The existing
mqprio framework is extended to configure the queue counts and
layout and also added support for rate limiting. This is achieved
through new netlink attributes for the 'mode' option which takes
values such as 'dcb' (default) and 'channel' and a 'shaper' option
for QoS attributes such as bandwidth rate limits in hw mode 1.
Legacy devices can fall back to the existing setup supporting hw mode
1 without these additional options where only the TCs are offloaded
and then the 'mode' and 'shaper' options defaults to DCB support.
The i40e driver enables the new mqprio hardware offload mechanism
factoring the TCs, queue configuration and bandwidth rates by
creating HW channel VSIs.

In this new mode, the priority to traffic class mapping and the
user specified queue ranges are used to configure the traffic
class when the 'mode' option is set to 'channel'. This is achieved by
creating HW channels(VSI). A new channel is created for each of the
traffic class configuration offloaded via mqprio framework except for
the first TC (TC0) which is for the main VSI. TC0 for the main VSI is
also reconfigured as per user provided queue parameters. Finally,
bandwidth rate limits are set on these traffic classes through the
shaper attribute by sending these rates in addition to the number of
TCs and the queue configurations.

Example:
     # tc qdisc add dev eth0 root mqprio num_tc 2 map 0 0 0 0 1 1 1 1\
       queues 4@0 4@4 hw 1 mode channel shaper bw_rlimit\
       min_rate 1Gbit 2Gbit max_rate 4Gbit 5Gbit

     To dump the bandwidth rates:

     # tc qdisc show dev eth0

     qdisc mqprio 804a: root  tc 2 map 0 0 0 0 1 1 1 1 0 0 0 0 0 0 0 0
                  queues:(0:3) (4:7)
                  mode:channel
                  shaper:bw_rlimit   min_rate:1Gbit 2Gbit   max_rate:4Gbit 5Gbit

---

Amritha Nambiar (6):
       mqprio: Introduce new hardware offload mode and shaper in mqprio
       i40e: Add macro for PF reset bit
       i40e: Add infrastructure for queue channel support
       i40e: Enable 'channel' mode in mqprio for TC configs
       i40e: Refactor VF BW rate limiting
       i40e: Add support setting TC max bandwidth rates

It would be nice to know what has changed since the last review, either 
summarized here or in the individual patch files.  This helps in knowing 
how much attention should be given to this new set of patches, and 
encourages further review.  I don't remember seeing any responses to my 
previous comments, and it looks like not all of them were acted upon.

For all those patch files that have changed since the last revision, I
have captured all the new changes in the section titled "v3: " of each
patch file. Also, I had replied to most of your comments that they'll be
fixed in v3 and the one in the mqprio patch that error handling was
already being done and these responses can be verified in patchwork. I
missed to respond to your comment regarding supporting macvlan offloads
through these channels, that will not be a part of this series and will
be looked upon at a later time in a subsequent patch series.

sln

quoted

  drivers/net/ethernet/intel/i40e/i40e.h             |   44 +
  drivers/net/ethernet/intel/i40e/i40e_debugfs.c     |    3
  drivers/net/ethernet/intel/i40e/i40e_ethtool.c     |    8
  drivers/net/ethernet/intel/i40e/i40e_main.c        | 1463 +++++++++++++++++---
  drivers/net/ethernet/intel/i40e/i40e_txrx.h        |    2
  drivers/net/ethernet/intel/i40e/i40e_virtchnl_pf.c |   50 -
  include/net/pkt_cls.h                              |    9
  include/uapi/linux/pkt_sched.h                     |   32
  net/sched/sch_mqprio.c                             |  183 ++-
  9 files changed, 1551 insertions(+), 243 deletions(-)

--
_______________________________________________
Intel-wired-lan mailing list
Intel-wired-lan@osuosl.org
https://lists.osuosl.org/mailman/listinfo/intel-wired-lan