Messages in this thread | | | Date | Fri, 22 Nov 2013 20:24:00 +0100 | From | Chang <> | Subject | Re: [PATCH] net: sctp: set chunk->tsn_gap_acked at the end of cycle |
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On 11/22/2013 03:27 PM, Vlad Yasevich wrote: > On 11/22/2013 02:49 AM, Chang Xiangzhong wrote: >> tsn_gap_acked is an important state flag in chunk, which indicates if the >> chunk has been acked in gap reports before. > Actually, this bit indicates simply that the chunk has been acked. It > doesn't state whether it's been acked in a gap report or via cumulative tsn. Thanks for pointing this out. Sorry for not having made that clear. > >> SFR-CACC algorithm depends on this >> variable. So set this at the end of each iteration, otherwise the SFR-CACC >> algorithm would never be toggled. >> >> Signed-off-by: Chang Xiangzhong <changxiangzhong@gmail.com> >> --- >> net/sctp/outqueue.c | 3 ++- >> 1 file changed, 2 insertions(+), 1 deletion(-) >> >> diff --git a/net/sctp/outqueue.c b/net/sctp/outqueue.c >> index 1b494fa..bff828c 100644 >> --- a/net/sctp/outqueue.c >> +++ b/net/sctp/outqueue.c >> @@ -1396,7 +1396,6 @@ static void sctp_check_transmitted(struct sctp_outq *q, >> * while DATA was outstanding). >> */ >> if (!tchunk->tsn_gap_acked) { >> - tchunk->tsn_gap_acked = 1; >> if (TSN_lt(*highest_new_tsn_in_sack, tsn)) >> *highest_new_tsn_in_sack = tsn; >> bytes_acked += sctp_data_size(tchunk); >> @@ -1460,6 +1459,8 @@ static void sctp_check_transmitted(struct sctp_outq *q, >> */ >> list_add_tail(lchunk, &tlist); >> } >> + >> + tchunk->tsn_gap_acked = 1; > The current code will set the state if it hasn't been set yet. Why is > this needed? Because in line 1420 ~ 1440 The SFR-CACC algorithms use tsn_gap_acked. That "if block" would never be triggered because the varaiable's been set. That's why I move the "state changing sentence" to the end of the iteration. > Now there is an issue with tracking highest_new_tsn_in_sack. The spec > is a little vague on this, but the highest_new_tsn_in_sack only supposed > to track tsns that have not been resent. If a tsn has been reneged, and > then sent again, it is not considered 'new' thus should not count > toward highest_new_tsn_in_sack. We currently do not track this right. I'll try to figure this out. > -vlad > > -vlad > >> } else { >> if (tchunk->tsn_gap_acked) { >> pr_debug("%s: receiver reneged on data TSN:0x%x\n", >>
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