RE: Re: [net-next PATCH v3] octeontx2-pf: Add ucast filter count configurability via devlink.

[Sai Krishna Gajula]

> -----Original Message-----
> From: Jacob Keller <jacob.e.keller@xxxxxxxxx>
> Sent: Friday, May 31, 2024 12:08 AM
> To: Sai Krishna Gajula <saikrishnag@xxxxxxxxxxx>; davem@xxxxxxxxxxxxx;
> edumazet@xxxxxxxxxx; kuba@xxxxxxxxxx; pabeni@xxxxxxxxxx;
> netdev@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; Sunil Kovvuri
> Goutham <sgoutham@xxxxxxxxxxx>; Geethasowjanya Akula
> <gakula@xxxxxxxxxxx>; Hariprasad Kelam <hkelam@xxxxxxxxxxx>;
> Subbaraya Sundeep Bhatta <sbhatta@xxxxxxxxxxx>
> Subject: Re: [net-next PATCH v3] octeontx2-pf: Add ucast filter
> count configurability via devlink.
> 
> 
> On 5/30/2024 3:15 AM, Sai Krishna wrote:
> > Added a devlink param to set/modify unicast filter count. Currently
> > it's hardcoded with a macro.
> >
> > commands:
> >
> > To get the current unicast filter count  # devlink dev param show
> > pci/0002:02:00.0 name unicast_filter_count
> >
> > To change/set the unicast filter count  # devlink dev param  set
> > pci/0002:02:00.0  name unicast_filter_count  value 5 cmode runtime
> >
> 
> A bit of explanation about why this needs to be configurable would be
> useful. What is the impact of lowering or raising this value? Presumably
> you need to change the MCAM table size? Lowering this on one port might
> enable raising it on another?
> 
> It seems reasonable to me, but it is helpful to provide such motivations
> in the commit message.

Ack, will add more info to commit message in patch V4.

> 
> > Signed-off-by: Sai Krishna <saikrishnag@xxxxxxxxxxx>
> > ---
> > v3:
> >     - Addressed review comments given by Jakub Kicinski
> >         1. Documented unicast_filter_count devlink param
> >         2. Minor change to match upstream code base
> > v2:
> >     - Addressed review comments given by Simon Horman
> > 	1. Updated the commit message with example commads
> >         2. Modified/optimized conditions
> >
> >  .../networking/devlink/octeontx2.rst          | 16 +++++
> >  .../marvell/octeontx2/nic/otx2_common.h       |  7 +-
> >  .../marvell/octeontx2/nic/otx2_devlink.c      | 64 +++++++++++++++++++
> >  .../marvell/octeontx2/nic/otx2_flows.c        | 20 +++---
> >  .../ethernet/marvell/octeontx2/nic/otx2_pf.c  |  2 +-
> >  5 files changed, 95 insertions(+), 14 deletions(-)
> >
> > diff --git a/Documentation/networking/devlink/octeontx2.rst
> b/Documentation/networking/devlink/octeontx2.rst
> > index 610de99b728a..5910289b4d4e 100644
> > --- a/Documentation/networking/devlink/octeontx2.rst
> > +++ b/Documentation/networking/devlink/octeontx2.rst
> > @@ -40,3 +40,19 @@ The ``octeontx2 AF`` driver implements the following
> driver-specific parameters.
> >       - runtime
> >       - Use to set the quantum which hardware uses for scheduling among
> transmit queues.
> >         Hardware uses weighted DWRR algorithm to schedule among all
> transmit queues.
> > +
> > +The ``octeontx2 PF`` driver implements the following driver-specific
> parameters.
> > +
> > +.. list-table:: Driver-specific parameters implemented
> > +   :widths: 5 5 5 85
> > +
> > +   * - Name
> > +     - Type
> > +     - Mode
> > +     - Description
> > +   * - ``unicast_filter_count``
> > +     - u8
> > +     - runtime
> > +     - Used to Set/modify unicast filter count, which helps in better utilization
> of
> > +       resources against possible wastage(un-used) with current scheme of
> hardcoded
> > +       unicast count.
> 
> The text here could be worded a little better. Once the patch is applied
> then hard coding is no longer the "current scheme".
> 
> I might have worded this like:
> 
> "Set the maximum number of unicast filters that can be programmed for
> the device. This can be used to achieve better device resource
> utilization, avoiding over consumption of unused MCAM table entries."
> 
> Or something similar.

Ack, will re-word the text..  in patch V4.

Thanks,
Sai