Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759857Ab3JPCNP (ORCPT ); Tue, 15 Oct 2013 22:13:15 -0400 Received: from mail-qe0-f52.google.com ([209.85.128.52]:36105 "EHLO mail-qe0-f52.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757698Ab3JPCNL (ORCPT ); Tue, 15 Oct 2013 22:13:11 -0400 Message-ID: <525DF632.1030507@gmail.com> Date: Tue, 15 Oct 2013 22:13:06 -0400 From: Vlad Yasevich User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Thunderbird/24.0 MIME-Version: 1.0 To: Chang Xiangzhong CC: nhorman@tuxdriver.com, davem@davemloft.net, linux-sctp@vger.kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH V2] For for each TSN t being newly acked (Not only cumulatively, but also SELECTIVELY) cacc_saw_newack should be set to 1. References: <1381860784-16481-1-git-send-email-changxiangzhong@gmail.com> In-Reply-To: <1381860784-16481-1-git-send-email-changxiangzhong@gmail.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 5478 Lines: 164 On 10/15/2013 02:13 PM, Chang Xiangzhong wrote: > Signed-off-by: Xiangzhong Chang Your proposed solution is very nice, but it does 2 things in one patch. 1) It fixes the bug 2) It refactors the code to improve the flow. While (2) is very nice, it needs a much more careful review. Can you please split this into 2 patches? First patch can make the code look like this: if (sctp_acked(sack, tsn)) { ... if (!tchunk->tsn_gap_acked) { tchunk->tsn_gap_acked = 1; *highest_new_tsn_in_sack = tsn; bytes_acked += sctp_data_size(tchunk); if (!tchunk->transport) migrate_bytes += sctp_data_size(tchunk); forward_progress = true; /* * SFR-CACC algorithm: * 2) If the SACK contains gap acks * and the flag CHANGEOVER_ACTIVE is * set the receiver of the SACK MUST * take the following action: ... } } Then you can file a second patch to improve the flow/refactor the function. You have to be very careful here though and be sure to run through all the regression tests since you would be modifying a very critcal part of the code. Thanks -vlad > --- > net/sctp/outqueue.c | 76 ++++++++++++++++++++++++--------------------------- > 1 file changed, 35 insertions(+), 41 deletions(-) > > diff --git a/net/sctp/outqueue.c b/net/sctp/outqueue.c > index 94df758..84ef3b8 100644 > --- a/net/sctp/outqueue.c > +++ b/net/sctp/outqueue.c > @@ -1357,13 +1357,13 @@ static void sctp_check_transmitted(struct sctp_outq *q, > > tsn = ntohl(tchunk->subh.data_hdr->tsn); > if (sctp_acked(sack, tsn)) { > - /* If this queue is the retransmit queue, the > - * retransmit timer has already reclaimed > - * the outstanding bytes for this chunk, so only > - * count bytes associated with a transport. > - */ > - if (transport) { > - /* If this chunk is being used for RTT > + if (!tchunk->tsn_gap_acked) { > + /* If this queue is the retransmit queue, the > + * retransmit timer has already reclaimed > + * the outstanding bytes for this chunk, so only > + * count bytes associated with a transport. > + * > + * If this chunk is being used for RTT > * measurement, calculate the RTT and update > * the RTO using this value. > * > @@ -1374,28 +1374,44 @@ static void sctp_check_transmitted(struct sctp_outq *q, > * first instance of the packet or a later > * instance). > */ > - if (!tchunk->tsn_gap_acked && > - tchunk->rtt_in_progress) { > + if (transport && tchunk->rtt_in_progress) { > tchunk->rtt_in_progress = 0; > rtt = jiffies - tchunk->sent_at; > sctp_transport_update_rto(transport, > - rtt); > + rtt); > } > - } > > - /* If the chunk hasn't been marked as ACKED, > - * mark it and account bytes_acked if the > - * chunk had a valid transport (it will not > - * have a transport if ASCONF had deleted it > - * while DATA was outstanding). > - */ > - if (!tchunk->tsn_gap_acked) { > + /* If the chunk hasn't been marked as ACKED, > + * mark it and account bytes_acked if the > + * chunk had a valid transport (it will not > + * have a transport if ASCONF had deleted it > + * while DATA was outstanding). > + */ > tchunk->tsn_gap_acked = 1; > *highest_new_tsn_in_sack = tsn; > bytes_acked += sctp_data_size(tchunk); > if (!tchunk->transport) > migrate_bytes += sctp_data_size(tchunk); > forward_progress = true; > + > + /* SFR-CACC algorithm: > + * 2) If the SACK contains gap acks > + * and the flag CHANGEOVER_ACTIVE is > + * set the receiver of the SACK MUST > + * take the following action: > + * > + * B) For each TSN t being acked that > + * has not been acked in any SACK so > + * far, set cacc_saw_newack to 1 for > + * the destination that the TSN was > + * sent to. > + */ > + if (transport && > + sack->num_gap_ack_blocks && > + q->asoc->peer.primary_path->cacc. > + changeover_active > + ) > + transport->cacc.cacc_saw_newack = 1; > } > > if (TSN_lte(tsn, sack_ctsn)) { > @@ -1411,30 +1427,8 @@ static void sctp_check_transmitted(struct sctp_outq *q, > restart_timer = 1; > forward_progress = true; > > - if (!tchunk->tsn_gap_acked) { > - /* > - * SFR-CACC algorithm: > - * 2) If the SACK contains gap acks > - * and the flag CHANGEOVER_ACTIVE is > - * set the receiver of the SACK MUST > - * take the following action: > - * > - * B) For each TSN t being acked that > - * has not been acked in any SACK so > - * far, set cacc_saw_newack to 1 for > - * the destination that the TSN was > - * sent to. > - */ > - if (transport && > - sack->num_gap_ack_blocks && > - q->asoc->peer.primary_path->cacc. > - changeover_active) > - transport->cacc.cacc_saw_newack > - = 1; > - } > - > list_add_tail(&tchunk->transmitted_list, > - &q->sacked); > + &q->sacked); > } else { > /* RFC2960 7.2.4, sctpimpguide-05 2.8.2 > * M2) Each time a SACK arrives reporting > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/