[dpdk-dev] [PATCH 0/2] net/softnic: sw fall-back for traffic management

[Dumitrescu, Cristian]

> -----Original Message-----
> From: Stephen Hemminger [mailto:stephen at networkplumber.org]
> Sent: Friday, August 11, 2017 4:28 PM
> To: Singh, Jasvinder <jasvinder.singh at intel.com>
> Cc: dev at dpdk.org; Dumitrescu, Cristian <cristian.dumitrescu at intel.com>;
> Yigit, Ferruh <ferruh.yigit at intel.com>; hemant.agrawal at nxp.com;
> Jerin.JacobKollanukkaran at cavium.com; Lu, Wenzhuo
> <wenzhuo.lu at intel.com>
> Subject: Re: [dpdk-dev] [PATCH 0/2] net/softnic: sw fall-back for traffic
> management
> 
> On Fri, 26 May 2017 19:11:47 +0100
> Jasvinder Singh <jasvinder.singh at intel.com> wrote:
> 
> > The SoftNIC PMD provides SW fall-back option for the NICs not supporting
> > the Traffic Management (TM) features.
> >
> > SoftNIC PMD overview:
> > - The SW fall-back is based on the existing librte_sched DPDK library.
> > - The TM-agnostic port (the underlay device) is wrapped into a TM-aware
> >   softnic port (the overlay device).
> > - Once the overlay device (virtual device) is created, the configuration of
> >   the underlay device is taking place through the overlay device.
> > - The SoftNIC PMD is generic, i.e. it works for any underlay device PMD that
> >   implements the ethdev API.
> >
> >   Similarly to Ring PMD, the SoftNIC virtual device can be created in two
> > different ways:
> > 1. Through EAL command line (--vdev option)_
> > 2._Through the rte_eth_softnic_create() API function called by the
> application
> >
> > SoftNIC PMD params:
> > - iface (mandatory): the ethdev port name (i.e. PCI address or vdev name)
> for
> > the underlay device
> > - txq_id (optional, default = 0): tx queue id of the underlay device
> > - deq_bsz (optional, default = 24): traffic manager dequeue burst size
> > - Example:_ --vdev 'net_softnic0,iface=0000:04:00.1,txq_id=0,deq_bsz=28'
> >
> > SoftNIC PMD build instructions:
> > - To build SoftNIC PMD, the following parameter needs to be set on
> > config/common_base file: CONFIG_RTE_LIBRTE_PMD_SOFTNIC=y
> > - The SoftNIC PMD depends on the TM API [1] and therefore is initially
> > targeted for the tm-next repository
> >
> >
> > Patch 1 adds softnic device PMD for traffic management.
> > Patch 2 adds traffic management ops to the softnic device suggested in
> > generic ethdev API for traffic management[1].
> >
> > [1] TM API version 4:_
> > http://www.dpdk.org/dev/patchwork/patch/24411/,
> > http://www.dpdk.org/dev/patchwork/patch/24412/
> >
> >
> > Jasvinder Singh (2):
> >   net/softnic: add softnic PMD for traffic management
> >   net/softnic: add traffic management ops
> >
> >  MAINTAINERS                                     |    5 +
> >  config/common_base                              |    5 +
> >  drivers/net/Makefile                            |    5 +
> >  drivers/net/softnic/Makefile                    |   58 ++
> >  drivers/net/softnic/rte_eth_softnic.c           |  578 ++++++++++++
> >  drivers/net/softnic/rte_eth_softnic.h           |   99 ++
> >  drivers/net/softnic/rte_eth_softnic_default.c   | 1104
> +++++++++++++++++++++++
> >  drivers/net/softnic/rte_eth_softnic_internals.h |   93 ++
> >  drivers/net/softnic/rte_eth_softnic_tm.c        |  235 +++++
> >  drivers/net/softnic/rte_eth_softnic_version.map |    7 +
> >  mk/rte.app.mk                                   |    5 +-
> >  11 files changed, 2193 insertions(+), 1 deletion(-)
> >  create mode 100644 drivers/net/softnic/Makefile
> >  create mode 100644 drivers/net/softnic/rte_eth_softnic.c
> >  create mode 100644 drivers/net/softnic/rte_eth_softnic.h
> >  create mode 100644 drivers/net/softnic/rte_eth_softnic_default.c
> >  create mode 100644 drivers/net/softnic/rte_eth_softnic_internals.h
> >  create mode 100644 drivers/net/softnic/rte_eth_softnic_tm.c
> >  create mode 100644 drivers/net/softnic/rte_eth_softnic_version.map
> >
> 
> Setting up a softnic plus hardware NIC is significantly more effort for
> applications
> than just using ethdev. Also, it puts the burden on the application to decide
> which
> hardware device needs softnic and which does not; putting hardware
> knowledge in the
> application is the wrong architectural direction.
> 
> Why not just the simple method of putting an new field in ethdev_ops for
> TM.
> If it is NULL, then rte_ethdev TM would just fallback to doing the SoftNIC
> processing?
> 
> Also, eth_dev_ops doesn't always have to be const. Aren't there some
> PMD's that
> insert different values based on configuration or CPU?

Hi Stephen,

Can you please review V3 and not V1?

Code is very much improved, and we have a list of Q&As that address  your questions straight away.

Thanks,
Cristian