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Diffstat (limited to 'net/ipv4/tcp_dctcp.c')
-rw-r--r--net/ipv4/tcp_dctcp.c36
1 files changed, 18 insertions, 18 deletions
diff --git a/net/ipv4/tcp_dctcp.c b/net/ipv4/tcp_dctcp.c
index cd4814f7e962..359da68d7c06 100644
--- a/net/ipv4/tcp_dctcp.c
+++ b/net/ipv4/tcp_dctcp.c
@@ -67,11 +67,6 @@ static unsigned int dctcp_alpha_on_init __read_mostly = DCTCP_MAX_ALPHA;
module_param(dctcp_alpha_on_init, uint, 0644);
MODULE_PARM_DESC(dctcp_alpha_on_init, "parameter for initial alpha value");
-static unsigned int dctcp_clamp_alpha_on_loss __read_mostly;
-module_param(dctcp_clamp_alpha_on_loss, uint, 0644);
-MODULE_PARM_DESC(dctcp_clamp_alpha_on_loss,
- "parameter for clamping alpha on loss");
-
static struct tcp_congestion_ops dctcp_reno;
static void dctcp_reset(const struct tcp_sock *tp, struct dctcp *ca)
@@ -164,21 +159,23 @@ static void dctcp_update_alpha(struct sock *sk, u32 flags)
}
}
-static void dctcp_state(struct sock *sk, u8 new_state)
+static void dctcp_react_to_loss(struct sock *sk)
{
- if (dctcp_clamp_alpha_on_loss && new_state == TCP_CA_Loss) {
- struct dctcp *ca = inet_csk_ca(sk);
+ struct dctcp *ca = inet_csk_ca(sk);
+ struct tcp_sock *tp = tcp_sk(sk);
- /* If this extension is enabled, we clamp dctcp_alpha to
- * max on packet loss; the motivation is that dctcp_alpha
- * is an indicator to the extend of congestion and packet
- * loss is an indicator of extreme congestion; setting
- * this in practice turned out to be beneficial, and
- * effectively assumes total congestion which reduces the
- * window by half.
- */
- ca->dctcp_alpha = DCTCP_MAX_ALPHA;
- }
+ ca->loss_cwnd = tp->snd_cwnd;
+ tp->snd_ssthresh = max(tp->snd_cwnd >> 1U, 2U);
+}
+
+static void dctcp_state(struct sock *sk, u8 new_state)
+{
+ if (new_state == TCP_CA_Recovery &&
+ new_state != inet_csk(sk)->icsk_ca_state)
+ dctcp_react_to_loss(sk);
+ /* We handle RTO in dctcp_cwnd_event to ensure that we perform only
+ * one loss-adjustment per RTT.
+ */
}
static void dctcp_cwnd_event(struct sock *sk, enum tcp_ca_event ev)
@@ -190,6 +187,9 @@ static void dctcp_cwnd_event(struct sock *sk, enum tcp_ca_event ev)
case CA_EVENT_ECN_NO_CE:
dctcp_ece_ack_update(sk, ev, &ca->prior_rcv_nxt, &ca->ce_state);
break;
+ case CA_EVENT_LOSS:
+ dctcp_react_to_loss(sk);
+ break;
default:
/* Don't care for the rest. */
break;