From: Florian Fainelli <f.fainelli@gmail•com>
To: roopa <roopa@cumulusnetworks•com>, sfeldma@gmail•com
Cc: netdev@vger•kernel.org, jiri@resnulli•us, linux@roeck-us•net,
andrew@lunn•ch, gospo@cumulusnetworks•com, vbandaru@broadcom•com,
siva.mannem.lnx@gmail•com
Subject: Re: [PATCH net-next RFC 0/5] Add NTF_EXT_AGED to control FDB ageing in SW or HW
Date: Fri, 20 Feb 2015 11:13:46 -0800 [thread overview]
Message-ID: <54E7876A.3060303@gmail.com> (raw)
In-Reply-To: <54E76EFA.1050209@cumulusnetworks.com>
On 20/02/15 09:29, roopa wrote:
> On 2/19/15, 11:09 PM, sfeldma@gmail•com wrote:
>> From: Scott Feldman <sfeldma@gmail•com>
>>
>> Add a new NTF_EXT_FLAG to mark an FDB as externally aged, for example by
>> offload hardware. Switchdev driver/devices can set this flag when
>> learning a
>> new FDB entry and SW (the bridge driver) will skip this entry when
>> running its
>> ageing task. If flag is set, the driver/device is responsible for
>> calling
>> call_netdev_switch_notifiers(NETDEV_SWITCH_FDB_DEL, ...) when entry
>> expires.
>>
>> This give the flexibility for driver/device to decide ageing policy
>> based on
>> its capabilities. For devices managing many FDB entries, it is
>> desireable for
>> the device to aged out its own entries. Devices not capable of aged
>> entries
>> can rely of SW to age out the entries.
>>
> scott, patches look good. However, I am not sure yet if there is a need
> to make it a per fdb entry flag.
I agree, in fact, most of the HW I have access to only has a global age
timer configuration knob. Is this configurable on a per-port basis for
higher end switches, or even maybe per-FDB entry?
>
> At some point we will also need the hw ageing parameter to be configurable.
> So other approach could be,
> - ageing parameter on bridge gets offloaded the hw
> - so, by default hw and kernel age their own entries using the same
> bridge device default timer
> - User can explicitly disable HW ageing by using self (this needs some
> more thought because now the call is on the bridge device)
I think we want to be careful with both SW and HW aging entries since a
host CPU's clock might be suspended/drifting etc.. at least, we probably
want one or the other to take precedence other the other one?
--
Florian
next prev parent reply other threads:[~2015-02-20 19:14 UTC|newest]
Thread overview: 30+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-02-20 7:09 [PATCH net-next RFC 0/5] Add NTF_EXT_AGED to control FDB ageing in SW or HW sfeldma
2015-02-20 7:09 ` [PATCH net-next RFC 1/5] neighbour: add external aged flag sfeldma
2015-02-20 7:09 ` [PATCH net-next RFC 2/5] switchdev: add ntf_flags to FDB notifier sfeldma
2015-02-20 7:09 ` [PATCH net-next RFC 3/5] bridge: call external learn add if adding FDB entry with NTF_EXT_LEARNED set sfeldma
2015-02-20 7:09 ` [PATCH net-next RFC 4/5] bridge: let HW control FDB ageing by setting NTF_EXT_AGED sfeldma
2015-02-20 17:31 ` David Miller
2015-02-20 7:09 ` [PATCH net-next RFC 5/5] rocker: explicitly set SW ageing for rocker sfeldma
2015-02-20 9:46 ` Jiri Pirko
2015-02-20 14:56 ` Scott Feldman
2015-02-20 17:29 ` [PATCH net-next RFC 0/5] Add NTF_EXT_AGED to control FDB ageing in SW or HW roopa
2015-02-20 19:13 ` Florian Fainelli [this message]
2015-02-20 19:45 ` Guenter Roeck
2015-02-21 0:20 ` Viswanath Bandaru
2015-02-21 0:39 ` Guenter Roeck
2015-02-21 18:29 ` roopa
[not found] ` <CAE4R7bAPS1GZKaC4M6x9cqfTOkVju1+Po4KzanfSniEFX9oi1w@mail.gmail.com>
2015-02-25 14:31 ` Andrew Lunn
2015-02-25 16:43 ` Guenter Roeck
2015-02-25 17:31 ` B Viswanath
2015-02-25 18:39 ` Guenter Roeck
2015-02-25 18:51 ` B Viswanath
2015-02-25 19:15 ` Guenter Roeck
2015-02-25 19:33 ` B Viswanath
2015-02-25 20:03 ` Guenter Roeck
2015-02-25 17:29 ` David Miller
2015-02-21 11:03 ` Jiri Pirko
2015-02-21 11:29 ` Viswanath Bandaru
2015-02-21 15:50 ` Jiri Pirko
2015-02-21 17:20 ` Viswanath Bandaru
2015-02-21 18:31 ` roopa
2015-02-21 1:23 ` Siva Mannem
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