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authorIngo Molnar <mingo@elte.hu>2010-04-02 22:02:55 +0400
committerIngo Molnar <mingo@elte.hu>2010-04-02 22:03:08 +0400
commitc9494727cf293ae2ec66af57547a3e79c724fec2 (patch)
tree44ae197b64fa7530ee695a90ad31326dda06f1e1 /net/ipv4/tcp_input.c
parent6427462bfa50f50dc6c088c07037264fcc73eca1 (diff)
parent42be79e37e264557f12860fa4cc84b4de3685954 (diff)
downloadlinux-c9494727cf293ae2ec66af57547a3e79c724fec2.tar.xz
Merge branch 'linus' into sched/core
Merge reason: update to latest upstream Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'net/ipv4/tcp_input.c')
-rw-r--r--net/ipv4/tcp_input.c15
1 files changed, 15 insertions, 0 deletions
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index 3fddc69ccccc..c096a4218b8f 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -89,6 +89,8 @@ int sysctl_tcp_frto __read_mostly = 2;
int sysctl_tcp_frto_response __read_mostly;
int sysctl_tcp_nometrics_save __read_mostly;
+int sysctl_tcp_thin_dupack __read_mostly;
+
int sysctl_tcp_moderate_rcvbuf __read_mostly = 1;
int sysctl_tcp_abc __read_mostly;
@@ -2447,6 +2449,16 @@ static int tcp_time_to_recover(struct sock *sk)
return 1;
}
+ /* If a thin stream is detected, retransmit after first
+ * received dupack. Employ only if SACK is supported in order
+ * to avoid possible corner-case series of spurious retransmissions
+ * Use only if there are no unsent data.
+ */
+ if ((tp->thin_dupack || sysctl_tcp_thin_dupack) &&
+ tcp_stream_is_thin(tp) && tcp_dupack_heuristics(tp) > 1 &&
+ tcp_is_sack(tp) && !tcp_send_head(sk))
+ return 1;
+
return 0;
}
@@ -2499,6 +2511,9 @@ static void tcp_mark_head_lost(struct sock *sk, int packets)
int err;
unsigned int mss;
+ if (packets == 0)
+ return;
+
WARN_ON(packets > tp->packets_out);
if (tp->lost_skb_hint) {
skb = tp->lost_skb_hint;