All the mail mirrored from lore.kernel.org
 help / color / mirror / Atom feed
From: Tobias Waldekranz <tobias@waldekranz.com>
To: Vladimir Oltean <olteanv@gmail.com>
Cc: davem@davemloft.net, kuba@kernel.org, andrew@lunn.ch,
	vivien.didelot@gmail.com, f.fainelli@gmail.com,
	netdev@vger.kernel.org
Subject: Re: [PATCH net-next 4/5] net: dsa: mv88e6xxx: Offload bridge learning flag
Date: Wed, 17 Mar 2021 19:45:46 +0100	[thread overview]
Message-ID: <87k0q5obz9.fsf@waldekranz.com> (raw)
In-Reply-To: <20210317141224.ssll7nt64lqym3wg@skbuf>

On Wed, Mar 17, 2021 at 16:12, Vladimir Oltean <olteanv@gmail.com> wrote:
> On Mon, Mar 15, 2021 at 10:13:59PM +0100, Tobias Waldekranz wrote:
>> +	if (flags.mask & BR_LEARNING) {
>> +		u16 pav = (flags.val & BR_LEARNING) ? (1 << port) : 0;
>> +
>> +		err = mv88e6xxx_port_set_assoc_vector(chip, port, pav);
>> +		if (err)
>> +			goto out;
>> +	}
>> +
>
> If flags.val & BR_LEARNING is off, could you please call
> mv88e6xxx_port_fast_age too? This ensures that existing ATU entries that
> were automatically learned are purged.

This opened up another can of worms.

It turns out that the hardware is incapable of fast aging a LAG. I can
see two workarounds. Both are awful in their own special ways:

1. Iterate over all entries of all FIDs in the ATU, removing all
   matching dynamic entries. This will accomplish the same thing, but it
   is a very expensive operation, and having that in the control path of
   STP does not feel quite right.

2. Flushing all dynamic entries in the entire ATU. Fast, but obviously
   results in a period of lots of flooded packets.

Any opinion on which approach you think would hurt less? Or, even
better, if there is a third way that I have missed.

For this series I am leaning towards making mv88e6xxx_port_fast_age a
no-op for LAG ports. We could then come back to this problem when we add
other LAG-related FDB operations like static FDB entries. Acceptable?

  reply	other threads:[~2021-03-17 18:46 UTC|newest]

Thread overview: 24+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-03-15 21:13 [PATCH net-next 0/5] net: dsa: mv88e6xxx: Offload bridge port flags Tobias Waldekranz
2021-03-15 21:13 ` [PATCH net-next 1/5] net: dsa: mv88e6xxx: Provide generic VTU iterator Tobias Waldekranz
2021-03-16  8:42   ` Vladimir Oltean
2021-03-17  9:41     ` Tobias Waldekranz
2021-03-18  1:34   ` Andrew Lunn
2021-03-15 21:13 ` [PATCH net-next 2/5] net: dsa: mv88e6xxx: Remove some bureaucracy around querying the VTU Tobias Waldekranz
2021-03-16  9:17   ` Vladimir Oltean
2021-03-17  9:46     ` Tobias Waldekranz
2021-03-15 21:13 ` [PATCH net-next 3/5] net: dsa: mv88e6xxx: Flood all traffic classes on standalone ports Tobias Waldekranz
2021-03-16  9:19   ` Vladimir Oltean
2021-03-17 22:33   ` Florian Fainelli
2021-03-18  1:38   ` Andrew Lunn
2021-03-15 21:13 ` [PATCH net-next 4/5] net: dsa: mv88e6xxx: Offload bridge learning flag Tobias Waldekranz
2021-03-16  9:27   ` Vladimir Oltean
2021-03-17  9:57     ` Tobias Waldekranz
2021-03-17 14:12   ` Vladimir Oltean
2021-03-17 18:45     ` Tobias Waldekranz [this message]
2021-03-17 19:29       ` Vladimir Oltean
2021-03-17 22:32         ` Tobias Waldekranz
2021-03-15 21:14 ` [PATCH net-next 5/5] net: dsa: mv88e6xxx: Offload bridge broadcast flooding flag Tobias Waldekranz
2021-03-16  9:39   ` Vladimir Oltean
2021-03-17 11:14     ` Tobias Waldekranz
2021-03-17 11:24       ` Vladimir Oltean
2021-03-18  1:50       ` Andrew Lunn

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=87k0q5obz9.fsf@waldekranz.com \
    --to=tobias@waldekranz.com \
    --cc=andrew@lunn.ch \
    --cc=davem@davemloft.net \
    --cc=f.fainelli@gmail.com \
    --cc=kuba@kernel.org \
    --cc=netdev@vger.kernel.org \
    --cc=olteanv@gmail.com \
    --cc=vivien.didelot@gmail.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.