On Wed, Jul 6, 2022 at 3:28 PM Vladimir Oltean <olteanv@xxxxxxxxx> wrote:
>
> On Tue, Jul 05, 2022 at 05:05:52PM +0200, Hans S wrote:
> > Hi, does anybody know what it going on with this variable?
> > struct dsa_port *dp ->ageing_time;
> >
> > I experience that it changes value like a factor ~10 at times.
>
> Could you be a bit more specific? Are you talking about STP Topology
> Change Notification BPDUs, which trigger this code path?
>
> diff --git a/net/bridge/br_stp.c b/net/bridge/br_stp.c
> index 7d27b2e6038f..9b25bc2dcb3e 100644
> --- a/net/bridge/br_stp.c
> +++ b/net/bridge/br_stp.c
> @@ -671,10 +671,10 @@ void __br_set_topology_change(struct net_bridge *br, unsigned char val)
>
> if (val) {
> t = 2 * br->forward_delay;
> - br_debug(br, "decreasing ageing time to %lu\n", t);
> + br_info(br, "decreasing ageing time to %lu\n", t);
> } else {
> t = br->bridge_ageing_time;
> - br_debug(br, "restoring ageing time to %lu\n", t);
> + br_info(br, "restoring ageing time to %lu\n", t);
> }
>
> err = __set_ageing_time(br->dev, t);
>
> Coincidentally the default values of 2 * br->forward_delay and br->bridge_ageing_time
> are 1 order of magnitude apart from each other.
>
> [ 139.998310] br0: topology change detected, propagating
> [ 140.003490] br0: decreasing ageing time to 3000
> [ 175.193054] br0: restoring ageing time to 30000
>
> What's the problem anyway?
It might be a topology change as you indicate, though I am not sure.
So I am not using that variable any more for determining the ageing
time for the locked FDB entries, but instead I have made a function to
read the time from the chip instead.
The problem with that, I have mentioned in my latest reply to the
mac-auth patch set...
