Implement TFRC-SP calc of mean length of loss intervals accordingly to
section 3 of RFC 4828
Changes:
- Modify tfrc_sp_lh_calc_i_mean header, now receiving the current
ccval, so it can determine
if a loss interval is too recent
- Consider number of losses in each loss interval
- Only consider open loss interval if it is at least 2 rtt old
- Changes function signatures as necessary
Signed-off-by: Ivo Calado, Erivaldo Xavier, Leandro Sales
<ivocalado@xxxxxxxxxxxxxxxxxxxx>, <desadoc@xxxxxxxxx>,
<leandroal@xxxxxxxxx>
Index: b/net/dccp/ccids/lib/loss_interval_sp.c
===================================================================
--- a/net/dccp/ccids/lib/loss_interval_sp.c 2009-08-26
23:28:27.000000000 -0300
+++ b/net/dccp/ccids/lib/loss_interval_sp.c 2009-08-26
23:53:32.000000000 -0300
@@ -66,10 +66,11 @@
}
}
-static void tfrc_sp_lh_calc_i_mean(struct tfrc_loss_hist *lh)
+static void tfrc_sp_lh_calc_i_mean(struct tfrc_loss_hist *lh, __u8 curr_ccval)
{
u32 i_i, i_tot0 = 0, i_tot1 = 0, w_tot = 0;
int i, k = tfrc_lh_length(lh) - 1; /* k is as in rfc3448bis, 5.4 */
+ u32 losses;
if (k <= 0)
return;
@@ -77,6 +78,14 @@
for (i = 0; i <= k; i++) {
i_i = tfrc_lh_get_interval(lh, i);
+ if (SUB16(curr_ccval,
tfrc_lh_get_loss_interval(lh,i)->li_ccval) <= 8)
+ {
+ losses = tfrc_lh_get_loss_interval(lh,i)->li_losses;
+
+ if (losses > 0)
+ i_i = div64_u64(i_i, losses);
+ }
+
if (i < k) {
i_tot0 += i_i * tfrc_lh_weights[i];
w_tot += tfrc_lh_weights[i];
@@ -86,6 +95,12 @@
}
lh->i_mean = max(i_tot0, i_tot1) / w_tot;
+ BUG_ON(w_tot == 0);
+ if (SUB16(curr_ccval, tfrc_lh_get_loss_interval(lh,0)->li_ccval) > 8) {
+ lh->i_mean = max(i_tot0, i_tot1) / w_tot;
+ } else {
+ lh->i_mean = i_tot1 / w_tot;
+ }
}
/**
@@ -126,7 +141,7 @@
return;
cur->li_length = len;
- tfrc_sp_lh_calc_i_mean(lh);
+ tfrc_sp_lh_calc_i_mean(lh, dccp_hdr(skb)->dccph_ccval);
}
/* RFC 4342, 10.2: test for the existence of packet with sequence number S */
@@ -145,7 +160,7 @@
* Updates I_mean and returns 1 if a new interval has in fact been
added to @lh.
*/
bool tfrc_sp_lh_interval_add(struct tfrc_loss_hist *lh, struct
tfrc_rx_hist *rh,
- u32 (*calc_first_li)(struct sock *),
struct sock *sk)
+ u32 (*calc_first_li)(struct sock *),
struct sock *sk, __u8 ccval)
{
struct tfrc_loss_interval *cur = tfrc_lh_peek(lh);
struct tfrc_rx_hist_entry *cong_evt;
@@ -214,7 +229,7 @@
if (lh->counter > (2*LIH_SIZE))
lh->counter -= LIH_SIZE;
- tfrc_sp_lh_calc_i_mean(lh);
+ tfrc_sp_lh_calc_i_mean(lh, ccval);
}
return true;
Index: b/net/dccp/ccids/lib/loss_interval_sp.h
===================================================================
--- a/net/dccp/ccids/lib/loss_interval_sp.h 2009-08-26
22:52:20.000000000 -0300
+++ b/net/dccp/ccids/lib/loss_interval_sp.h 2009-08-26
23:44:20.000000000 -0300
@@ -71,7 +71,7 @@
#endif
extern bool tfrc_sp_lh_interval_add(struct tfrc_loss_hist *, struct
tfrc_rx_hist *,
- u32 (*first_li)(struct sock *),
struct sock *);
+ u32 (*first_li)(struct sock *),
struct sock *, __u8 ccval);
extern void tfrc_sp_lh_update_i_mean(struct tfrc_loss_hist *lh,
struct sk_buff *);
extern void tfrc_sp_lh_cleanup(struct tfrc_loss_hist *lh);
Index: b/net/dccp/ccids/lib/packet_history_sp.c
===================================================================
--- a/net/dccp/ccids/lib/packet_history_sp.c 2009-08-26
22:55:01.000000000 -0300
+++ b/net/dccp/ccids/lib/packet_history_sp.c 2009-08-26
23:49:59.000000000 -0300
@@ -359,7 +359,7 @@
/*
* Update Loss Interval database and recycle RX records
*/
- new_event = tfrc_sp_lh_interval_add(lh, h, first_li, sk);
+ new_event = tfrc_sp_lh_interval_add(lh, h, first_li, sk,
dccp_hdr(skb)->dccph_ccval);
__three_after_loss(h);
} else if (dccp_data_packet(skb) && dccp_skb_is_ecn_ce(skb)) {
@@ -368,7 +368,7 @@
* the RFC considers ECN marks - a future implementation may
* find it useful to also check ECN marks on non-data packets.
*/
- new_event = tfrc_sp_lh_interval_add(lh, h, first_li, sk);
+ new_event = tfrc_sp_lh_interval_add(lh, h, first_li, sk,
dccp_hdr(skb)->dccph_ccval);
/*
* Also combinations of loss and ECN-marks (as per the warning)
* are not supported. The permutations of loss combined with or
--
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