On (09/10/18 17:16), Cong Wang wrote: > > > > On (09/10/18 16:51), Cong Wang wrote: > > > > > > __rds_create_bind_key(key, addr, port, scope_id); > > > - rs = rhashtable_lookup_fast(&bind_hash_table, key, ht_parms); > > > + rcu_read_lock(); > > > + rs = rhashtable_lookup(&bind_hash_table, key, ht_parms); > > > if (rs && !sock_flag(rds_rs_to_sk(rs), SOCK_DEAD)) > > > rds_sock_addref(rs); > > > else > > > rs = NULL; > > > + rcu_read_unlock(); > > > > aiui, the rcu_read lock/unlock is only useful if the write > > side doing destructive operations does something to make sure readers > > are done before doing the destructive opertion. AFAIK, that does > > not exist for rds socket management today > > That is exactly why we need it here, right?
Maybe I am confused, what exactly is the patch you are proposing? Does it have the SOCK_RCU_FREE change? Does it have the rcu_read_lock you have above? Where is the call_rcu? > Hmm, so you are saying synchronize_rcu() is kinda more correct > than call_rcu()?? I'm not saying that, I'm asking "what exactly is the patch you are proposing?" The only one on record is http://patchwork.ozlabs.org/patch/968282/ which does not have either synchronize_rcu or call_rcu. > I never hear this before, would like to know why. Please post precise patches first. Thanks.
