On Wed, Nov 11, 2015 at 9:23 AM, Eric Dumazet <eric.duma...@gmail.com> wrote: > On Wed, 2015-11-11 at 09:05 -0800, Tom Herbert wrote: >> On Tue, Nov 10, 2015 at 10:19 PM, Eric Dumazet <eric.duma...@gmail.com> >> wrote: >> > On Tue, 2015-11-10 at 21:41 -0800, Tom Herbert wrote: >> >> Tolga, are you still planning to respin this patch (when tree opens?) >> > >> > I was planning to add an union on skc_tx_queue_mapping and >> > sk_max_ack_backlog, so that adding a check on sk_max_ack_backlog in >> > listener lookup would not add an additional cache line miss. >> > >> > This would remove false sharing because sk_ack_backlog is often dirtied >> > when a socket is added into accept queue. >> > >> That's sounds like good fixes, but my question was more about the >> problem originally described by Tolga where we are transitioning >> processing for a listener port from one process to another. I think >> the conclusion in this thread was to modify the code so that >> listen(fd, 0) would stop new connections from being assigned to a >> socket (as opposed to explicit SO_REUSEPORT_LISTEN_OFF option). Does >> this still seem reasonable? > > Actually listen(fd, 0) is not going to work well : > > For request_sock that were created (by incoming SYN packet) before this > listen(fd, 0) call, the 3rd packet (ACK coming from client) would not be > able to create a child attached to this listener. > > sk_acceptq_is_full() test in tcp_v4_syn_recv_sock() would simply drop > the thing. > > I was mainly objecting adding yet another socket option. > > Maybe setsockopt(... SO_REUSEPORT, &off, sizeof(off)) could detect the > condition automatically ? > How about doing this in shutdown called for a listener?
> (I am not sure current behavior of setting sk->sk_reuseport = valbool; > is correct if valbool==0 and current sk_reuseport is 1) > > > -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
