On 05/05/2021 02:26, Huang, Joseph wrote: >> If I may make a suggestion: I also work with mv88e6xxx systems, and we >> have the same issues with known multicast not being flooded to router >> ports. Knowing that chipset, I see what you are trying to do. >> >> But other chips may work differently. Imagine for example a switch where >> there is a separate vector of router ports that the hardware can OR in after >> looking up the group in the ATU. This implementation would render the >> performance gains possible on that device useless. As another example, you >> could imagine a device where an ATU operation exists that sets a bit in the >> vector of every group in a particular database; instead of having to update >> each entry individually. >> >> I think we (mv88e6xxx) will have to accept that we need to add the proper >> scaffolding to manage this on the driver side. That way the bridge can stay >> generic. The bridge could just provide some MDB iterator to save us from >> having to cache all the configured groups. >> >> So basically: >> >> - In mv88e6xxx, maintain a per-switch vector of router ports. >> >> - When a ports router state is toggled: >> 1. Update the vector. >> 2. Ask the bridge to iterate through all applicable groups and update >> the corresponding ATU entries. >> >> - When a new MDB entry is updated, make sure to also OR in the current >> vector of router ports in the DPV of the ATU entry. >> >> >> I would be happy to help out with testing of this! > > Thanks for the suggestion/offer! > > What patch 0002 does is that: > > - When an mrouter port is added/deleted, it iterates over the list of mdb's > to add/delete that port to/from the group in the hardware (I think this is > what your bullet #2 does as well, except that one is done in the bridge, > and the other is done in the driver) > > - When a group is added/deleted, it iterates over the list of mrouter ports > to add/delete the switchdev programming > > I think what Nik is objecting to is that with this approach, there's now > a for-loop in the call paths (thus it "increases the complexity with 1 order > of magnitude), however I can't think of a way to avoid the looping (whether > done inside the bridge or in the driver) but still achieve the same result > (for Marvell at least). > Note that I did not say to avoid it in the switchdev driver. :) I said it should be in the driver or in some user-space helper, but it mustn't affect non-switchdev software use cases so much. You can check how mlxsw[1] deals with mdbs and router ports. [1] drivers/net/ethernet/mellanox/mlxsw/spectrum_switchdev.c > I suspect that other SOHO switches might have this problem as well (Broadcom > comes to mind). > > Thanks, > Joseph >