On Thu, Mar 10, 2016 at 03:31:57PM +0800, Xin Long wrote:
> prior to this patch, at the beginning if we have two paths in one assoc,
> they may have the same params other than the last_time_heard, it will try
> the paths like this:
>
> 1st cycle
> try trans1 fail.
> then trans2 is selected.(cause it's last_time_heard is after trans1).
>
> 2nd cycle:
> try trans2 fail
> then trans2 is selected.(cause it's last_time_heard is after trans1).
>
> 3rd cycle:
> try trans2 fail
> then trans2 is selected.(cause it's last_time_heard is after trans1).
>
> ....
>
> trans1 will never have change to be selected, which is not what we expect.
> we should keeping round robin all the paths if they are just added at the
> beginning.
>
> So at first every tranport's last_time_heard should be initialized 0, so
> that we ensure they have the same value at the beginning, only by this,
> all the transports could get equal chance to be selected.
>
> Then for sctp_trans_elect_best, it should return the trans_next one when
> *trans == *trans_next, so that we can try next if it fails, but now it
> always return trans. so we can fix it by exchanging these two params when
> we calls sctp_trans_elect_tie().
>
> Fixes: 4c47af4d5eb2 ('net: sctp: rework multihoming retransmission path selection to rfc4960')
> Signed-off-by: Xin Long <lucien.xin@xxxxxxxxx>
Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@xxxxxxxxx>
> ---
> net/sctp/associola.c | 2 +-
> net/sctp/transport.c | 2 +-
> 2 files changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/net/sctp/associola.c b/net/sctp/associola.c
> index 2bf8ec9..cd87344 100644
> --- a/net/sctp/associola.c
> +++ b/net/sctp/associola.c
> @@ -1263,7 +1263,7 @@ static struct sctp_transport *sctp_trans_elect_best(struct sctp_transport *curr,
> if (score_curr > score_best)
> return curr;
> else if (score_curr == score_best)
> - return sctp_trans_elect_tie(curr, best);
> + return sctp_trans_elect_tie(best, curr);
> else
> return best;
> }
> diff --git a/net/sctp/transport.c b/net/sctp/transport.c
> index a431c14..d517153 100644
> --- a/net/sctp/transport.c
> +++ b/net/sctp/transport.c
> @@ -72,7 +72,7 @@ static struct sctp_transport *sctp_transport_init(struct net *net,
> */
> peer->rto = msecs_to_jiffies(net->sctp.rto_initial);
>
> - peer->last_time_heard = ktime_get();
> + peer->last_time_heard = ktime_set(0, 0);
> peer->last_time_ecne_reduced = jiffies;
>
> peer->param_flags = SPP_HB_DISABLE |
> --
> 2.1.0
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-sctp" in
> the body of a message to majordomo@xxxxxxxxxxxxxxx
> More majordomo info at http://vger.kernel.org/majordomo-info.html
>
--
To unsubscribe from this list: send the line "unsubscribe linux-sctp" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
