Merge branch 'drm-ttm-unmappable' into drm-core-next

[pandora-kernel.git] / net / ipv4 / tcp_input.c

diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index 3fddc69..f240f57 100644 (file)
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -62,6 +62,7 @@
  */
 
 #include <linux/mm.h>
+#include <linux/slab.h>
 #include <linux/module.h>
 #include <linux/sysctl.h>
 #include <linux/kernel.h>
@@ -89,6 +90,8 @@ 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 +2450,16 @@ 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 +2512,9 @@ 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;