sctp: Only mark chunks as missing when there are gaps

Frist small step in optimizing SACK processing.   Do not call
sctp_mark_missing() when there are no gaps reported and thus
not missing chunks.

Signed-off-by: Vlad Yasevich <vladislav.yasevich@hp.com>

diff --git a/net/sctp/outqueue.c b/net/sctp/outqueue.c
index 4328ad5439c9fa014f10cea4e9d17ab6b9ffbffd..ef5ea7423cc83d58668bad188e209ef115c4fed1 100644 (file)
--- a/net/sctp/outqueue.c
+++ b/net/sctp/outqueue.c
@@ -1129,12 +1129,13 @@ int sctp_outq_sack(struct sctp_outq *q, struct sctp_sackhdr *sack)
        unsigned outstanding;
        struct sctp_transport *primary = asoc->peer.primary_path;
        int count_of_newacks = 0;
+       int gap_ack_blocks;
 
        /* Grab the association's destination address list. */
        transport_list = &asoc->peer.transport_addr_list;
 
        sack_ctsn = ntohl(sack->cum_tsn_ack);
-
+       gap_ack_blocks = ntohs(sack->num_gap_ack_blocks);
        /*
         * SFR-CACC algorithm:
         * On receipt of a SACK the sender SHOULD execute the
@@ -1161,7 +1162,7 @@ int sctp_outq_sack(struct sctp_outq *q, struct sctp_sackhdr *sack)
         * A) Initialize the cacc_saw_newack to 0 for all destination
         * addresses.
         */
-       if (sack->num_gap_ack_blocks &&
+       if (gap_ack_blocks &&
            primary->cacc.changeover_active) {
                list_for_each_entry(transport, transport_list, transports) {
                        transport->cacc.cacc_saw_newack = 0;
@@ -1170,9 +1171,8 @@ int sctp_outq_sack(struct sctp_outq *q, struct sctp_sackhdr *sack)
 
        /* Get the highest TSN in the sack. */
        highest_tsn = sack_ctsn;
-       if (sack->num_gap_ack_blocks)
-               highest_tsn +=
-                   ntohs(frags[ntohs(sack->num_gap_ack_blocks) - 1].gab.end);
+       if (gap_ack_blocks)
+               highest_tsn += ntohs(frags[gap_ack_blocks - 1].gab.end);
 
        if (TSN_lt(asoc->highest_sacked, highest_tsn)) {
                highest_new_tsn = highest_tsn;
@@ -1181,11 +1181,11 @@ int sctp_outq_sack(struct sctp_outq *q, struct sctp_sackhdr *sack)
                highest_new_tsn = sctp_highest_new_tsn(sack, asoc);
        }
 
+
        /* Run through the retransmit queue.  Credit bytes received
         * and free those chunks that we can.
         */
        sctp_check_transmitted(q, &q->retransmit, NULL, sack, highest_new_tsn);
-       sctp_mark_missing(q, &q->retransmit, NULL, highest_new_tsn, 0);
 
        /* Run through the transmitted queue.
         * Credit bytes received and free those chunks which we can.
@@ -1204,9 +1204,12 @@ int sctp_outq_sack(struct sctp_outq *q, struct sctp_sackhdr *sack)
                        count_of_newacks ++;
        }
 
-       list_for_each_entry(transport, transport_list, transports) {
-               sctp_mark_missing(q, &transport->transmitted, transport,
-                                 highest_new_tsn, count_of_newacks);
+       if (gap_ack_blocks) {
+               sctp_mark_missing(q, &q->retransmit, NULL, highest_new_tsn, 0);
+
+               list_for_each_entry(transport, transport_list, transports)
+                       sctp_mark_missing(q, &transport->transmitted, transport,
+                                         highest_new_tsn, count_of_newacks);
        }
 
        /* Move the Cumulative TSN Ack Point if appropriate.  */