[DCCP] CCID2: Code optimizations
These are code optimizations which are relevant when dealing with large
windows. They are not coded the way I would like to, but they do the job for
the short-term. This patch should be more neat.
Commiter note: Changed the seqno comparisions to use {after,before}48 to handle
wrapping.
Signed-off-by: Andrea Bittau <a.bittau@cs.ucl.ac.uk>
Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
diff --git a/net/dccp/ccids/ccid2.c b/net/dccp/ccids/ccid2.c
index 162032b..6533cb2 100644
--- a/net/dccp/ccids/ccid2.c
+++ b/net/dccp/ccids/ccid2.c
@@ -619,7 +619,17 @@
}
ackno = DCCP_SKB_CB(skb)->dccpd_ack_seq;
- seqp = hctx->ccid2hctx_seqh->ccid2s_prev;
+ if (after48(ackno, hctx->ccid2hctx_high_ack))
+ hctx->ccid2hctx_high_ack = ackno;
+
+ seqp = hctx->ccid2hctx_seqt;
+ while (before48(seqp->ccid2s_seq, ackno)) {
+ seqp = seqp->ccid2s_next;
+ if (seqp == hctx->ccid2hctx_seqh) {
+ seqp = hctx->ccid2hctx_seqh->ccid2s_prev;
+ break;
+ }
+ }
/* If in slow-start, cwnd can increase at most Ack Ratio / 2 packets for
* this single ack. I round up.
@@ -697,7 +707,14 @@
/* The state about what is acked should be correct now
* Check for NUMDUPACK
*/
- seqp = hctx->ccid2hctx_seqh->ccid2s_prev;
+ seqp = hctx->ccid2hctx_seqt;
+ while (before48(seqp->ccid2s_seq, hctx->ccid2hctx_high_ack)) {
+ seqp = seqp->ccid2s_next;
+ if (seqp == hctx->ccid2hctx_seqh) {
+ seqp = hctx->ccid2hctx_seqh->ccid2s_prev;
+ break;
+ }
+ }
done = 0;
while (1) {
if (seqp->ccid2s_acked) {
@@ -771,6 +788,7 @@
hctx->ccid2hctx_lastrtt = 0;
hctx->ccid2hctx_rpdupack = -1;
hctx->ccid2hctx_last_cong = jiffies;
+ hctx->ccid2hctx_high_ack = 0;
hctx->ccid2hctx_rtotimer.function = &ccid2_hc_tx_rto_expire;
hctx->ccid2hctx_rtotimer.data = (unsigned long)sk;
