diff options
Diffstat (limited to 'net/ipv4/tcp_recovery.c')
| -rw-r--r-- | net/ipv4/tcp_recovery.c | 16 |
1 files changed, 10 insertions, 6 deletions
diff --git a/net/ipv4/tcp_recovery.c b/net/ipv4/tcp_recovery.c index 1e330a2f913d..4ecb38ae8504 100644 --- a/net/ipv4/tcp_recovery.c +++ b/net/ipv4/tcp_recovery.c @@ -1,7 +1,7 @@ #include <linux/tcp.h> #include <net/tcp.h> -int sysctl_tcp_recovery __read_mostly = TCP_RACK_LOST_RETRANS; +int sysctl_tcp_recovery __read_mostly = TCP_RACK_LOSS_DETECTION; static void tcp_rack_mark_skb_lost(struct sock *sk, struct sk_buff *skb) { @@ -24,7 +24,9 @@ static bool tcp_rack_sent_after(const struct skb_mstamp *t1, (t1->v64 == t2->v64 && after(seq1, seq2)); } -/* Marks a packet lost, if some packet sent later has been (s)acked. +/* RACK loss detection (IETF draft draft-ietf-tcpm-rack-01): + * + * Marks a packet lost, if some packet sent later has been (s)acked. * The underlying idea is similar to the traditional dupthresh and FACK * but they look at different metrics: * @@ -37,8 +39,10 @@ static bool tcp_rack_sent_after(const struct skb_mstamp *t1, * is being more resilient to reordering by simply allowing some * "settling delay", instead of tweaking the dupthresh. * - * The current version is only used after recovery starts but can be - * easily extended to detect the first loss. + * When tcp_rack_detect_loss() detects some packets are lost and we + * are not already in the CA_Recovery state, either tcp_rack_reo_timeout() + * or tcp_time_to_recover()'s "Trick#1: the loss is proven" code path will + * make us enter the CA_Recovery state. */ static void tcp_rack_detect_loss(struct sock *sk, const struct skb_mstamp *now, u32 *reo_timeout) @@ -54,7 +58,7 @@ static void tcp_rack_detect_loss(struct sock *sk, const struct skb_mstamp *now, * to queuing or delayed ACKs. */ reo_wnd = 1000; - if (tp->rack.reord && tcp_min_rtt(tp) != ~0U) + if ((tp->rack.reord || !tp->lost_out) && tcp_min_rtt(tp) != ~0U) reo_wnd = max(tcp_min_rtt(tp) >> 2, reo_wnd); tcp_for_write_queue(skb, sk) { @@ -105,7 +109,7 @@ void tcp_rack_mark_lost(struct sock *sk, const struct skb_mstamp *now) struct tcp_sock *tp = tcp_sk(sk); u32 timeout; - if (inet_csk(sk)->icsk_ca_state < TCP_CA_Recovery || !tp->rack.advanced) + if (!tp->rack.advanced) return; /* Reset the advanced flag to avoid unnecessary queue scanning */ |