From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757645Ab3KYSRq (ORCPT ); Mon, 25 Nov 2013 13:17:46 -0500 Received: from mail-yh0-f50.google.com ([209.85.213.50]:55585 "EHLO mail-yh0-f50.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757470Ab3KYSRj (ORCPT ); Mon, 25 Nov 2013 13:17:39 -0500 Message-ID: <5293943E.2000800@gmail.com> Date: Mon, 25 Nov 2013 13:17:34 -0500 From: Vlad Yasevich User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Thunderbird/24.1.0 MIME-Version: 1.0 To: Xufeng Zhang , nhorman@tuxdriver.com, davem@davemloft.net CC: linux-sctp@vger.kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [V2 PATCH] sctp: Restore 'resent' bit to avoid retransmitted chunks for RTT measurements References: <1385350017-11324-1-git-send-email-xufeng.zhang@windriver.com> In-Reply-To: <1385350017-11324-1-git-send-email-xufeng.zhang@windriver.com> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 11/24/2013 10:26 PM, Xufeng Zhang wrote: > Currently retransmitted DATA chunks could also be used for > RTT measurements since there are no flag to identify whether > the transmitted DATA chunk is a new one or a retransmitted one. > This problem is introduced by commit ae19c5486 ("sctp: remove > 'resent' bit from the chunk") which inappropriately removed the > 'resent' bit completely, instead of doing this, we should set > the resent bit only for the retransmitted DATA chunks. > > Signed-off-by: Xufeng Zhang Acked-by: Vlad Yasevich Thanks -vlad > --- > v1->v2: > Rmoved initialization for resent bit. > Combined two if clause > > include/net/sctp/structs.h | 1 + > net/sctp/output.c | 3 ++- > net/sctp/outqueue.c | 3 +++ > 3 files changed, 6 insertions(+), 1 deletions(-) > > diff --git a/include/net/sctp/structs.h b/include/net/sctp/structs.h > index 2174d8d..ea0ca5f 100644 > --- a/include/net/sctp/structs.h > +++ b/include/net/sctp/structs.h > @@ -629,6 +629,7 @@ struct sctp_chunk { > #define SCTP_NEED_FRTX 0x1 > #define SCTP_DONT_FRTX 0x2 > __u16 rtt_in_progress:1, /* This chunk used for RTT calc? */ > + resent:1, /* Has this chunk ever been resent. */ > has_tsn:1, /* Does this chunk have a TSN yet? */ > has_ssn:1, /* Does this chunk have a SSN yet? */ > singleton:1, /* Only chunk in the packet? */ > diff --git a/net/sctp/output.c b/net/sctp/output.c > index e650978..0e2644d 100644 > --- a/net/sctp/output.c > +++ b/net/sctp/output.c > @@ -474,10 +474,11 @@ int sctp_packet_transmit(struct sctp_packet *packet) > * for a given destination transport address. > */ > > - if (!tp->rto_pending) { > + if (!chunk->resent && !tp->rto_pending) { > chunk->rtt_in_progress = 1; > tp->rto_pending = 1; > } > + > has_data = 1; > } > > diff --git a/net/sctp/outqueue.c b/net/sctp/outqueue.c > index 94df758..70f4f56 100644 > --- a/net/sctp/outqueue.c > +++ b/net/sctp/outqueue.c > @@ -446,6 +446,8 @@ void sctp_retransmit_mark(struct sctp_outq *q, > transport->rto_pending = 0; > } > > + chunk->resent = 1; > + > /* Move the chunk to the retransmit queue. The chunks > * on the retransmit queue are always kept in order. > */ > @@ -1375,6 +1377,7 @@ static void sctp_check_transmitted(struct sctp_outq *q, > * instance). > */ > if (!tchunk->tsn_gap_acked && > + !tchunk->resent && > tchunk->rtt_in_progress) { > tchunk->rtt_in_progress = 0; > rtt = jiffies - tchunk->sent_at; >