Messages in this thread | | | From | Hans Schultz <> | Subject | Re: [PATCH V3 net-next 1/4] net: bridge: add fdb flag to extent locked port feature | Date | Tue, 24 May 2022 18:21:02 +0200 |
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> > Hi Hans, > So this approach has a fundamental problem, f->dst is changed without any synchronization > you cannot rely on it and thus you cannot account for these entries properly. We must be very > careful if we try to add any new synchronization not to affect performance as well. > More below... > >> @@ -319,6 +326,9 @@ static void fdb_delete(struct net_bridge *br, struct net_bridge_fdb_entry *f, >> if (test_bit(BR_FDB_STATIC, &f->flags)) >> fdb_del_hw_addr(br, f->key.addr.addr); >> >> + if (test_bit(BR_FDB_ENTRY_LOCKED, &f->flags) && !test_bit(BR_FDB_OFFLOADED, &f->flags)) >> + atomic_dec(&f->dst->locked_entry_cnt); > > Sorry but you cannot do this for multiple reasons: > - f->dst can be NULL > - f->dst changes without any synchronization > - there is no synchronization between fdb's flags and its ->dst > > Cheers, > Nik
Hi Nik,
if a port is decoupled from the bridge, the locked entries would of course be invalid, so maybe if adding and removing a port is accounted for wrt locked entries and the count of locked entries, would that not work?
Best, Hans
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