Date: Fri, 9 Sep 2011 13:52:37 +0000 (UTC) From: Michael Tuexen <tuexen@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r225462 - head/sys/netinet Message-ID: <201109091352.p89DqbHD040712@svn.freebsd.org>
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Author: tuexen Date: Fri Sep 9 13:52:37 2011 New Revision: 225462 URL: http://svn.freebsd.org/changeset/base/225462 Log: Improve implementation of the Nagle algorithm for SCTP: Don't delay the final fragment of a fragmented user message. Approved by: re MFC after: 4 weeks Modified: head/sys/netinet/sctp_output.c Modified: head/sys/netinet/sctp_output.c ============================================================================== --- head/sys/netinet/sctp_output.c Fri Sep 9 11:59:59 2011 (r225461) +++ head/sys/netinet/sctp_output.c Fri Sep 9 13:52:37 2011 (r225462) @@ -9821,19 +9821,22 @@ sctp_chunk_output(struct sctp_inpcb *inp unsigned int burst_cnt = 0; struct timeval now; int now_filled = 0; - int nagle_on = 0; + int nagle_on; int frag_point = sctp_get_frag_point(stcb, &stcb->asoc); int un_sent = 0; int fr_done; unsigned int tot_frs = 0; asoc = &stcb->asoc; + /* The Nagle algorithm is only applied when handling a send call. */ if (from_where == SCTP_OUTPUT_FROM_USR_SEND) { if (sctp_is_feature_on(inp, SCTP_PCB_FLAGS_NODELAY)) { nagle_on = 0; } else { nagle_on = 1; } + } else { + nagle_on = 0; } SCTP_TCB_LOCK_ASSERT(stcb); @@ -10007,15 +10010,18 @@ sctp_chunk_output(struct sctp_inpcb *inp } } if (nagle_on) { - /*- - * When nagle is on, we look at how much is un_sent, then - * if its smaller than an MTU and we have data in - * flight we stop. + /* + * When the Nagle algorithm is used, look at how + * much is unsent, then if its smaller than an MTU + * and we have data in flight we stop, except if we + * are handling a fragmented user message. */ un_sent = ((stcb->asoc.total_output_queue_size - stcb->asoc.total_flight) + (stcb->asoc.stream_queue_cnt * sizeof(struct sctp_data_chunk))); if ((un_sent < (int)(stcb->asoc.smallest_mtu - SCTP_MIN_OVERHEAD)) && - (stcb->asoc.total_flight > 0)) { + (stcb->asoc.total_flight > 0) && + ((stcb->asoc.locked_on_sending == NULL) || + sctp_is_feature_on(inp, SCTP_PCB_FLAGS_EXPLICIT_EOR))) { break; } }
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