[DCCP] CCID2: Add helper functions for changing important CCID2 state
Introduce methods which manipulate interesting congestion control
state such as pipe and rtt estimate. This is useful for people
wishing to monitor the variables of CCID and instrument the code
[perhaps using Kprobes]. Personally, I am a fan of
encapsulation---that justifies this change =D.
Signed-off-by: Andrea Bittau <a.bittau@cs.ucl.ac.uk>
Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/dccp/ccids/ccid2.c b/net/dccp/ccids/ccid2.c
index b88da03..457dd3d 100644
--- a/net/dccp/ccids/ccid2.c
+++ b/net/dccp/ccids/ccid2.c
@@ -199,6 +199,17 @@
hctx->ccid2hctx_cwnd = val;
}
+static void ccid2_change_srtt(struct ccid2_hc_tx_sock *hctx, long val)
+{
+ ccid2_pr_debug("change SRTT to %ld\n", val);
+ hctx->ccid2hctx_srtt = val;
+}
+
+static void ccid2_change_pipe(struct ccid2_hc_tx_sock *hctx, long val)
+{
+ hctx->ccid2hctx_pipe = val;
+}
+
static void ccid2_start_rto_timer(struct sock *sk);
static void ccid2_hc_tx_rto_expire(unsigned long data)
@@ -228,7 +239,7 @@
ccid2_start_rto_timer(sk);
/* adjust pipe, cwnd etc */
- hctx->ccid2hctx_pipe = 0;
+ ccid2_change_pipe(hctx, 0);
hctx->ccid2hctx_ssthresh = hctx->ccid2hctx_cwnd >> 1;
if (hctx->ccid2hctx_ssthresh < 2)
hctx->ccid2hctx_ssthresh = 2;
@@ -274,7 +285,7 @@
BUG_ON(!hctx->ccid2hctx_sendwait);
hctx->ccid2hctx_sendwait = 0;
- hctx->ccid2hctx_pipe++;
+ ccid2_change_pipe(hctx, hctx->ccid2hctx_pipe + 1);
BUG_ON(hctx->ccid2hctx_pipe < 0);
/* There is an issue. What if another packet is sent between
@@ -470,11 +481,13 @@
if (hctx->ccid2hctx_srtt == -1) {
ccid2_pr_debug("R: %lu Time=%lu seq=%llu\n",
r, jiffies, seqp->ccid2s_seq);
- hctx->ccid2hctx_srtt = r;
+ ccid2_change_srtt(hctx, r);
hctx->ccid2hctx_rttvar = r >> 1;
} else {
/* RTTVAR */
long tmp = hctx->ccid2hctx_srtt - r;
+ long srtt;
+
if (tmp < 0)
tmp *= -1;
@@ -484,10 +497,12 @@
hctx->ccid2hctx_rttvar += tmp;
/* SRTT */
- hctx->ccid2hctx_srtt *= 7;
- hctx->ccid2hctx_srtt >>= 3;
+ srtt = hctx->ccid2hctx_srtt;
+ srtt *= 7;
+ srtt >>= 3;
tmp = r >> 3;
- hctx->ccid2hctx_srtt += tmp;
+ srtt += tmp;
+ ccid2_change_srtt(hctx, srtt);
}
s = hctx->ccid2hctx_rttvar << 2;
/* clock granularity is 1 when based on jiffies */
@@ -523,7 +538,7 @@
{
struct ccid2_hc_tx_sock *hctx = ccid2_hc_tx_sk(sk);
- hctx->ccid2hctx_pipe--;
+ ccid2_change_pipe(hctx, hctx->ccid2hctx_pipe-1);
BUG_ON(hctx->ccid2hctx_pipe < 0);
if (hctx->ccid2hctx_pipe == 0)
@@ -749,7 +764,7 @@
hctx->ccid2hctx_sent = 0;
hctx->ccid2hctx_rto = 3 * HZ;
- hctx->ccid2hctx_srtt = -1;
+ ccid2_change_srtt(hctx, -1);
hctx->ccid2hctx_rttvar = -1;
hctx->ccid2hctx_lastrtt = 0;
hctx->ccid2hctx_rpdupack = -1;