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authorScott Feldman <sfeldma@gmail.com>2015-09-23 18:39:20 +0300
committerDavid S. Miller <davem@davemloft.net>2015-09-24 00:35:58 +0300
commit45ffda75e145ed7a2b40f6a5de35431d7e62d1f0 (patch)
tree356b5084c6b138fc48e67f63e339bd67c629912a /Documentation/networking
parentdcd45e06496ca586db35949d1d92d48aab8a0a00 (diff)
downloadlinux-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/networking')
-rw-r--r--Documentation/networking/switchdev.txt24
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
^^^^^^^^^^^^^^^^^^^^^^^^