Re: [PATCH iwl-net v2] ice: add a separate Rx handler for flow director commands

[Michal Kubiak <michal.kubiak@intel.com>]

On Wed, May 14, 2025 at 01:50:22PM -0700, Jacob Keller wrote:
> 
> 
> On 5/14/2025 5:37 AM, Michal Kubiak wrote:
> > The "ice" driver implementation uses the control VSI to handle
> > the flow director configuration for PFs and VFs.
> > 
> > Unfortunately, although a separate VSI type was created to handle flow
> > director queues, the Rx queue handler was shared between the flow
> > director and a standard NAPI Rx handler.
> > 
> > Such a design approach was not very flexible. First, it mixed hotpath
> > and slowpath code, blocking their further optimization. It also created
> > a huge overkill for the flow director command processing, which is
> > descriptor-based only, so there is no need to allocate Rx data buffers.
> > 
> > For the above reasons, implement a separate Rx handler for the control
> > VSI. Also, remove from the NAPI handler the code dedicated to
> > configuring the flow director rules on VFs.
> > Do not allocate Rx data buffers to the flow director queues because
> > their processing is descriptor-based only.
> > Finally, allow Rx data queues to be allocated only for VSIs that have
> > netdev assigned to them.
> > 
> > This handler splitting approach is the first step in converting the
> > driver to use the Page Pool (which can only be used for data queues).
> > 
> > Test hints:
> >   1. Create a VF for any PF managed by the ice driver.
> >   2. In a loop, add and delete flow director rules for the VF, e.g.:
> > 
> >        for i in {1..128}; do
> >            q=$(( i % 16 ))
> >            ethtool -N ens802f0v0 flow-type tcp4 dst-port "$i" action "$q"
> >        done
> > 
> >        for i in {0..127}; do
> >            ethtool -N ens802f0v0 delete "$i"
> >        done
> > 
> > Suggested-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
> > Suggested-by: Michal Swiatkowski <michal.swiatkowski@intel.com>
> > Acked-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
> > Reviewed-by: Jacob Keller <jacob.e.keller@intel.com>
> > Reviewed-by: Przemek Kitszel <przemyslaw.kitszel@intel.com>
> > Reviewed-by: Simon Horman <horms@kernel.org>
> > Signed-off-by: Michal Kubiak <michal.kubiak@intel.com>
> > ---
> 
> I assume you meant for this to be still targeted at iwl-next and the
> iwl-net was a typo?
> 
> I'll queue on the next dev-queue.
> 
> Thanks,
> Jake


You are right. Of course, it was a typo. My apologies for that!
Thank you for your vigilance and double-checking!

Thanks,
Michal