[ovs-dev] [PATCH v3 3/7] dpif-netdev: add subtable-lookup-get command for usability

[Van Haaren, Harry]

> -----Original Message-----
> From: William Tu <u9012063 at gmail.com>
> Sent: Wednesday, June 17, 2020 4:57 PM
> To: Van Haaren, Harry <harry.van.haaren at intel.com>
> Cc: ovs-dev <ovs-dev at openvswitch.org>; Stokes, Ian <ian.stokes at intel.com>;
> Ilya Maximets <i.maximets at ovn.org>; Federico Iezzi <fiezzi at redhat.com>
> Subject: Re: [PATCH v3 3/7] dpif-netdev: add subtable-lookup-get command for
> usability
> 
> On Wed, Jun 17, 2020 at 8:50 AM Van Haaren, Harry
> <harry.van.haaren at intel.com> wrote:
> >
> > > -----Original Message-----
> > > From: William Tu <u9012063 at gmail.com>
> > > Sent: Tuesday, June 16, 2020 4:42 PM
> > > To: Van Haaren, Harry <harry.van.haaren at intel.com>
> > > Cc: ovs-dev <ovs-dev at openvswitch.org>; Stokes, Ian
> <ian.stokes at intel.com>;
> > > Ilya Maximets <i.maximets at ovn.org>; Federico Iezzi <fiezzi at redhat.com>
> > > Subject: Re: [PATCH v3 3/7] dpif-netdev: add subtable-lookup-get command
> for
> > > usability
> > >
> > > On Wed, Jun 10, 2020 at 3:47 AM Harry van Haaren
> > > <harry.van.haaren at intel.com> wrote:
> > > >
> > > > This commit introduces a new command, "dpif-netdev/subtable-lookup-
> get"
> > > add prio
> >
> > Hey William,
> >
> > Just reviewing your FB in detail here, today the commands work as follows:
> > - the "set" command is "subtable-lookup-prio-set"
> > - the "get" command is "subtable-lookup-get"       // Note : no "prio" here
> >
> > This is done on purpose - the get returns the list of subtable lookup
> implementations,
> > and is not really technically directly to do with "prio" . It does however, return
> the priority too...
> 
> I see, thanks
> >
> > Open to suggestions, would the more similar commands below be better?
> > subtable-lookup-prio-get
> > subtable-lookup-prio-set
> I don't have strong opinion, but I prefer
> subtable-lookup-prio-get
> subtable-lookup-prio-set

Great - 1 opinion is > no opinions, will change to the more similar style.

> btw, when we issue ovs-appctl subtable-lookup-get,
> does it show "for each subtable", its corresponding lookup function?
> Because each subtable might not always uses the highest prio lookup
> function, correct?

Great question - no - today the get command just returns the available
lookup function implementations, and NOT the detailed list of what
DPCLS subtable is matched with what implementation.

I agree this information may be useful - perhaps we could add a -v
version of the get command? Or dump it in another dpif-netdev/*
command? For example, the "dump miniflow bits" command as
Emma/Ian upstreamed in 2.13 might be a good fit?

If OK with you, I'll suggest we keep the functionality in this patchset as is
to focus on remaining opens & merge it. I'd be happy to look at improving
info/visibility into DPCLS subtable accelerations in a follow-up patchset?