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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