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| author | Scott Feldman <sfeldma@gmail.com> | 2015-09-23 18:39:20 +0300 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2015-09-24 00:35:58 +0300 |
| commit | 45ffda75e145ed7a2b40f6a5de35431d7e62d1f0 (patch) | |
| tree | 356b5084c6b138fc48e67f63e339bd67c629912a /Documentation | |
| parent | dcd45e06496ca586db35949d1d92d48aab8a0a00 (diff) | |
| download | linux-45ffda75e145ed7a2b40f6a5de35431d7e62d1f0.tar.xz | |
switchdev: update documentation on FDB ageing_time
Signed-off-by: Scott Feldman <sfeldma@gmail.com>
Reviewed-by: Vivien Didelot <vivien.didelot@savoirfairelinux.com>
Acked-by: Jiri Pirko <jiri@resnulli.us>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'Documentation')
| -rw-r--r-- | Documentation/networking/switchdev.txt | 24 |
1 files changed, 12 insertions, 12 deletions
diff --git a/Documentation/networking/switchdev.txt b/Documentation/networking/switchdev.txt index 476df0496686..67e43ee7840a 100644 --- a/Documentation/networking/switchdev.txt +++ b/Documentation/networking/switchdev.txt @@ -239,20 +239,20 @@ The driver should initialize the attributes to the hardware defaults. FDB Ageing ^^^^^^^^^^ -There are two FDB ageing models supported: 1) ageing by the device, and 2) -ageing by the kernel. Ageing by the device is preferred if many FDB entries -are supported. The driver calls call_switchdev_notifiers(SWITCHDEV_FDB_DEL, -...) to age out the FDB entry. In this model, ageing by the kernel should be -turned off. XXX: how to turn off ageing in kernel on a per-port basis or -otherwise prevent the kernel from ageing out the FDB entry? - -In the kernel ageing model, the standard bridge ageing mechanism is used to age -out stale FDB entries. To keep an FDB entry "alive", the driver should refresh -the FDB entry by calling call_switchdev_notifiers(SWITCHDEV_FDB_ADD, ...). The +The bridge will skip ageing FDB entries marked with NTF_EXT_LEARNED and it is +the responsibility of the port driver/device to age out these entries. If the +port device supports ageing, when the FDB entry expires, it will notify the +driver which in turn will notify the bridge with SWITCHDEV_FDB_DEL. If the +device does not support ageing, the driver can simulate ageing using a +garbage collection timer to monitor FBD entries. Expired entries will be +notified to the bridge using SWITCHDEV_FDB_DEL. See rocker driver for +example of driver running ageing timer. + +To keep an NTF_EXT_LEARNED entry "alive", the driver should refresh the FDB +entry by calling call_switchdev_notifiers(SWITCHDEV_FDB_ADD, ...). The notification will reset the FDB entry's last-used time to now. The driver should rate limit refresh notifications, for example, no more than once a -second. If the FDB entry expires, fdb_delete is called to remove entry from -the device. +second. (The last-used time is visible using the bridge -s fdb option). STP State Change on Port ^^^^^^^^^^^^^^^^^^^^^^^^ |