21 files changed, 414 insertions, 201 deletions

diff --git a/Documentation/networking/ip-sysctl.txt b/Documentation/networking/ip-sysctl.txt
index 65895bb51414..ebc09a159f62 100644
--- a/Documentation/networking/ip-sysctl.txt
+++ b/Documentation/networking/ip-sysctl.txt
@@ -78,6 +78,11 @@ inet_peer_gc_maxtime - INTEGER
 
 TCP variables: 
 
+tcp_abc - INTEGER
+        Controls Appropriate Byte Count defined in RFC3465. If set to
+        0 then does congestion avoid once per ack. 1 is conservative
+        value, and 2 is more agressive.
+
 tcp_syn_retries - INTEGER
         Number of times initial SYNs for an active TCP connection attempt
         will be retransmitted. Should not be higher than 255. Default value
diff --git a/drivers/sbus/char/display7seg.c b/drivers/sbus/char/display7seg.c
index 2c86a4b809cd..c3a51d1fae5d 100644
--- a/drivers/sbus/char/display7seg.c
+++ b/drivers/sbus/char/display7seg.c
@@ -119,7 +119,7 @@ static long d7s_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 {
         __u8 regs = readb(d7s_regs);
         __u8 ireg = 0;
-        int error = 0
+        int error = 0;
 
         if (D7S_MINOR != iminor(file->f_dentry->d_inode))
                 return -ENODEV;
diff --git a/drivers/scsi/lpfc/lpfc_init.c b/drivers/scsi/lpfc/lpfc_init.c
index c90723860a04..07498118359d 100644
--- a/drivers/scsi/lpfc/lpfc_init.c
+++ b/drivers/scsi/lpfc/lpfc_init.c
@@ -1704,7 +1704,6 @@ MODULE_DEVICE_TABLE(pci, lpfc_id_table);
 
 static struct pci_driver lpfc_driver = {
         .name           = LPFC_DRIVER_NAME,
-        .owner          = THIS_MODULE,
         .id_table       = lpfc_id_table,
         .probe          = lpfc_pci_probe_one,
         .remove         = __devexit_p(lpfc_pci_remove_one),
diff --git a/include/linux/sysctl.h b/include/linux/sysctl.h
index 22cf5e1ac987..ab2791b3189d 100644
--- a/include/linux/sysctl.h
+++ b/include/linux/sysctl.h
@@ -390,6 +390,7 @@ enum
         NET_TCP_BIC_BETA=108,
         NET_IPV4_ICMP_ERRORS_USE_INBOUND_IFADDR=109,
         NET_TCP_CONG_CONTROL=110,
+        NET_TCP_ABC=111,
 };
 
 enum {
diff --git a/include/linux/tcp.h b/include/linux/tcp.h
index ac4ca44c75ca..0e1da6602e05 100644
--- a/include/linux/tcp.h
+++ b/include/linux/tcp.h
@@ -307,6 +307,21 @@ struct tcp_sock {
         struct tcp_sack_block duplicate_sack[1]; /* D-SACK block */
         struct tcp_sack_block selective_acks[4]; /* The SACKS themselves*/
 
+        struct tcp_sack_block recv_sack_cache[4];
+
+        /* from STCP, retrans queue hinting */
+        struct sk_buff* lost_skb_hint;
+
+        struct sk_buff *scoreboard_skb_hint;
+        struct sk_buff *retransmit_skb_hint;
+        struct sk_buff *forward_skb_hint;
+        struct sk_buff *fastpath_skb_hint;
+
+        int     fastpath_cnt_hint;
+        int     lost_cnt_hint;
+        int     retransmit_cnt_hint;
+        int     forward_cnt_hint;
+
         __u16   advmss;         /* Advertised MSS                       */
         __u16   prior_ssthresh; /* ssthresh saved at recovery start     */
         __u32   lost_out;       /* Lost packets                 */
@@ -326,6 +341,7 @@ struct tcp_sock {
         __u32   snd_up;         /* Urgent pointer               */
 
         __u32   total_retrans;  /* Total retransmits for entire connection */
+        __u32   bytes_acked;    /* Appropriate Byte Counting - RFC3465 */
 
         unsigned int            keepalive_time;   /* time before keep alive takes place */
         unsigned int            keepalive_intvl;  /* time interval between keep alive probes */
diff --git a/include/net/sock.h b/include/net/sock.h
index ff13c4cc287a..982b4ecd187b 100644
--- a/include/net/sock.h
+++ b/include/net/sock.h
@@ -1247,6 +1247,12 @@ static inline struct page *sk_stream_alloc_page(struct sock *sk)
                      (skb != (struct sk_buff *)&(sk)->sk_write_queue);  \
                      skb = skb->next)
 
+/*from STCP for fast SACK Process*/
+#define sk_stream_for_retrans_queue_from(skb, sk)                       \
+                for (; (skb != (sk)->sk_send_head) &&                   \
+                     (skb != (struct sk_buff *)&(sk)->sk_write_queue);  \
+                     skb = skb->next)
+
 /*
  *      Default write policy as shown to user space via poll/select/SIGIO
  */
diff --git a/include/net/tcp.h b/include/net/tcp.h
index 96cc3b434e40..0f9848011972 100644
--- a/include/net/tcp.h
+++ b/include/net/tcp.h
@@ -89,10 +89,10 @@ extern void tcp_time_wait(struct sock *sk, int state, int timeo);
                                  */
 
 #define TCP_SYN_RETRIES  5      /* number of times to retry active opening a
-                                 * connection: ~180sec is RFC minumum   */
+                                 * connection: ~180sec is RFC minimum   */
 
 #define TCP_SYNACK_RETRIES 5    /* number of times to retry passive opening a
-                                 * connection: ~180sec is RFC minumum   */
+                                 * connection: ~180sec is RFC minimum   */
 
 
 #define TCP_ORPHAN_RETRIES 7    /* number of times to retry on an orphaned
@@ -180,7 +180,7 @@ extern void tcp_time_wait(struct sock *sk, int state, int timeo);
 /* Flags in tp->nonagle */
 #define TCP_NAGLE_OFF           1       /* Nagle's algo is disabled */
 #define TCP_NAGLE_CORK          2       /* Socket is corked         */
-#define TCP_NAGLE_PUSH          4       /* Cork is overriden for already queued data */
+#define TCP_NAGLE_PUSH          4       /* Cork is overridden for already queued data */
 
 extern struct inet_timewait_death_row tcp_death_row;
 
@@ -218,6 +218,7 @@ extern int sysctl_tcp_low_latency;
 extern int sysctl_tcp_nometrics_save;
 extern int sysctl_tcp_moderate_rcvbuf;
 extern int sysctl_tcp_tso_win_divisor;
+extern int sysctl_tcp_abc;
 
 extern atomic_t tcp_memory_allocated;
 extern atomic_t tcp_sockets_allocated;
@@ -551,13 +552,13 @@ extern u32	__tcp_select_window(struct sock *sk);
 
 /* TCP timestamps are only 32-bits, this causes a slight
  * complication on 64-bit systems since we store a snapshot
- * of jiffies in the buffer control blocks below.  We decidely
+ * of jiffies in the buffer control blocks below.  We decidedly
  * only use of the low 32-bits of jiffies and hide the ugly
  * casts with the following macro.
  */
 #define tcp_time_stamp          ((__u32)(jiffies))
 
-/* This is what the send packet queueing engine uses to pass
+/* This is what the send packet queuing engine uses to pass
  * TCP per-packet control information to the transmission
  * code.  We also store the host-order sequence numbers in
  * here too.  This is 36 bytes on 32-bit architectures,
@@ -597,7 +598,7 @@ struct tcp_skb_cb {
 #define TCPCB_EVER_RETRANS      0x80    /* Ever retransmitted frame     */
 #define TCPCB_RETRANS           (TCPCB_SACKED_RETRANS|TCPCB_EVER_RETRANS)
 
-#define TCPCB_URG               0x20    /* Urgent pointer advenced here */
+#define TCPCB_URG               0x20    /* Urgent pointer advanced here */
 
 #define TCPCB_AT_TAIL           (TCPCB_URG)
 
@@ -765,6 +766,33 @@ static inline __u32 tcp_current_ssthresh(const struct sock *sk)
                             (tp->snd_cwnd >> 2)));
 }
 
+/*
+ * Linear increase during slow start
+ */
+static inline void tcp_slow_start(struct tcp_sock *tp)
+{
+        if (sysctl_tcp_abc) {
+                /* RFC3465: Slow Start
+                 * TCP sender SHOULD increase cwnd by the number of
+                 * previously unacknowledged bytes ACKed by each incoming
+                 * acknowledgment, provided the increase is not more than L
+                 */
+                if (tp->bytes_acked < tp->mss_cache)
+                        return;
+
+                /* We MAY increase by 2 if discovered delayed ack */
+                if (sysctl_tcp_abc > 1 && tp->bytes_acked > 2*tp->mss_cache) {
+                        if (tp->snd_cwnd < tp->snd_cwnd_clamp)
+                                tp->snd_cwnd++;
+                }
+        }
+        tp->bytes_acked = 0;
+
+        if (tp->snd_cwnd < tp->snd_cwnd_clamp)
+                tp->snd_cwnd++;
+}
+
+
 static inline void tcp_sync_left_out(struct tcp_sock *tp)
 {
         if (tp->rx_opt.sack_ok &&
@@ -794,6 +822,7 @@ static inline void tcp_enter_cwr(struct sock *sk)
         struct tcp_sock *tp = tcp_sk(sk);
 
         tp->prior_ssthresh = 0;
+        tp->bytes_acked = 0;
         if (inet_csk(sk)->icsk_ca_state < TCP_CA_CWR) {
                 __tcp_enter_cwr(sk);
                 tcp_set_ca_state(sk, TCP_CA_CWR);
@@ -810,6 +839,27 @@ static __inline__ __u32 tcp_max_burst(const struct tcp_sock *tp)
         return 3;
 }
 
+/* RFC2861 Check whether we are limited by application or congestion window
+ * This is the inverse of cwnd check in tcp_tso_should_defer
+ */
+static inline int tcp_is_cwnd_limited(const struct sock *sk, u32 in_flight)
+{
+        const struct tcp_sock *tp = tcp_sk(sk);
+        u32 left;
+
+        if (in_flight >= tp->snd_cwnd)
+                return 1;
+
+        if (!(sk->sk_route_caps & NETIF_F_TSO))
+                return 0;
+
+        left = tp->snd_cwnd - in_flight;
+        if (sysctl_tcp_tso_win_divisor)
+                return left * sysctl_tcp_tso_win_divisor < tp->snd_cwnd;
+        else
+                return left <= tcp_max_burst(tp);
+}
+
 static __inline__ void tcp_minshall_update(struct tcp_sock *tp, int mss, 
                                            const struct sk_buff *skb)
 {
@@ -1157,6 +1207,15 @@ static inline void tcp_mib_init(void)
         TCP_ADD_STATS_USER(TCP_MIB_MAXCONN, -1);
 }
 
+/*from STCP */
+static inline void clear_all_retrans_hints(struct tcp_sock *tp){
+        tp->lost_skb_hint = NULL;
+        tp->scoreboard_skb_hint = NULL;
+        tp->retransmit_skb_hint = NULL;
+        tp->forward_skb_hint = NULL;
+        tp->fastpath_skb_hint = NULL;
+}
+
 /* /proc */
 enum tcp_seq_states {
         TCP_SEQ_STATE_LISTENING,
diff --git a/net/ipv4/sysctl_net_ipv4.c b/net/ipv4/sysctl_net_ipv4.c
index 652685623519..01444a02b48b 100644
--- a/net/ipv4/sysctl_net_ipv4.c
+++ b/net/ipv4/sysctl_net_ipv4.c
@@ -645,6 +645,14 @@ ctl_table ipv4_table[] = {
                 .proc_handler   = &proc_tcp_congestion_control,
                 .strategy       = &sysctl_tcp_congestion_control,
         },
+        {
+                .ctl_name       = NET_TCP_ABC,
+                .procname       = "tcp_abc",
+                .data           = &sysctl_tcp_abc,
+                .maxlen         = sizeof(int),
+                .mode           = 0644,
+                .proc_handler   = &proc_dointvec,
+        },
 
         { .ctl_name = 0 }
 };
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index 72b7c22e1ea5..9ac7a4f46bd8 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -1640,7 +1640,7 @@ int tcp_disconnect(struct sock *sk, int flags)
         } else if (tcp_need_reset(old_state) ||
                    (tp->snd_nxt != tp->write_seq &&
                     (1 << old_state) & (TCPF_CLOSING | TCPF_LAST_ACK))) {
-                /* The last check adjusts for discrepance of Linux wrt. RFC
+                /* The last check adjusts for discrepancy of Linux wrt. RFC
                  * states
                  */
                 tcp_send_active_reset(sk, gfp_any());
@@ -1669,6 +1669,7 @@ int tcp_disconnect(struct sock *sk, int flags)
         tp->packets_out = 0;
         tp->snd_ssthresh = 0x7fffffff;
         tp->snd_cwnd_cnt = 0;
+        tp->bytes_acked = 0;
         tcp_set_ca_state(sk, TCP_CA_Open);
         tcp_clear_retrans(tp);
         inet_csk_delack_init(sk);
diff --git a/net/ipv4/tcp_bic.c b/net/ipv4/tcp_bic.c
index ae35e0609047..1d0cd86621b1 100644
--- a/net/ipv4/tcp_bic.c
+++ b/net/ipv4/tcp_bic.c
@@ -217,17 +217,15 @@ static void bictcp_cong_avoid(struct sock *sk, u32 ack,
 
         bictcp_low_utilization(sk, data_acked);
 
-        if (in_flight < tp->snd_cwnd)
+        if (!tcp_is_cwnd_limited(sk, in_flight))
                 return;
 
-        if (tp->snd_cwnd <= tp->snd_ssthresh) {
-                /* In "safe" area, increase. */
-                if (tp->snd_cwnd < tp->snd_cwnd_clamp)
-                        tp->snd_cwnd++;
-        } else {
+        if (tp->snd_cwnd <= tp->snd_ssthresh)
+                tcp_slow_start(tp);
+        else {
                 bictcp_update(ca, tp->snd_cwnd);
 
-                /* In dangerous area, increase slowly.
+                /* In dangerous area, increase slowly.
                  * In theory this is tp->snd_cwnd += 1 / tp->snd_cwnd
                  */
                 if (tp->snd_cwnd_cnt >= ca->cnt) {
diff --git a/net/ipv4/tcp_cong.c b/net/ipv4/tcp_cong.c
index bbf2d6624e89..c7cc62c8dc12 100644
--- a/net/ipv4/tcp_cong.c
+++ b/net/ipv4/tcp_cong.c
@@ -186,24 +186,32 @@ void tcp_reno_cong_avoid(struct sock *sk, u32 ack, u32 rtt, u32 in_flight,
 {
         struct tcp_sock *tp = tcp_sk(sk);
 
-        if (in_flight < tp->snd_cwnd)
+        if (!tcp_is_cwnd_limited(sk, in_flight))
                 return;
 
-        if (tp->snd_cwnd <= tp->snd_ssthresh) {
-                /* In "safe" area, increase. */
-                if (tp->snd_cwnd < tp->snd_cwnd_clamp)
-                        tp->snd_cwnd++;
-        } else {
-                /* In dangerous area, increase slowly.
-                 * In theory this is tp->snd_cwnd += 1 / tp->snd_cwnd
-                 */
-                if (tp->snd_cwnd_cnt >= tp->snd_cwnd) {
-                        if (tp->snd_cwnd < tp->snd_cwnd_clamp)
-                                tp->snd_cwnd++;
-                        tp->snd_cwnd_cnt = 0;
-                } else
-                        tp->snd_cwnd_cnt++;
-        }
+        /* In "safe" area, increase. */
+        if (tp->snd_cwnd <= tp->snd_ssthresh)
+                tcp_slow_start(tp);
+
+        /* In dangerous area, increase slowly. */
+        else if (sysctl_tcp_abc) {
+                /* RFC3465: Apppriate Byte Count
+                 * increase once for each full cwnd acked
+                 */
+                if (tp->bytes_acked >= tp->snd_cwnd*tp->mss_cache) {
+                        tp->bytes_acked -= tp->snd_cwnd*tp->mss_cache;
+                        if (tp->snd_cwnd < tp->snd_cwnd_clamp)
+                                tp->snd_cwnd++;
+                }
+        } else {
+                /* In theory this is tp->snd_cwnd += 1 / tp->snd_cwnd */
+                if (tp->snd_cwnd_cnt >= tp->snd_cwnd) {
+                        if (tp->snd_cwnd < tp->snd_cwnd_clamp)
+                                tp->snd_cwnd++;
+                        tp->snd_cwnd_cnt = 0;
+                } else
+                        tp->snd_cwnd_cnt++;
+        }
 }
 EXPORT_SYMBOL_GPL(tcp_reno_cong_avoid);
 
diff --git a/net/ipv4/tcp_highspeed.c b/net/ipv4/tcp_highspeed.c
index 6acc04bde080..82b3c189bd7d 100644
--- a/net/ipv4/tcp_highspeed.c
+++ b/net/ipv4/tcp_highspeed.c
@@ -111,18 +111,17 @@ static void hstcp_init(struct sock *sk)
 }
 
 static void hstcp_cong_avoid(struct sock *sk, u32 adk, u32 rtt,
-                             u32 in_flight, int good)
+                             u32 in_flight, u32 pkts_acked)
 {
         struct tcp_sock *tp = tcp_sk(sk);
         struct hstcp *ca = inet_csk_ca(sk);
 
-        if (in_flight < tp->snd_cwnd)
+        if (!tcp_is_cwnd_limited(sk, in_flight))
                 return;
 
-        if (tp->snd_cwnd <= tp->snd_ssthresh) {
-                if (tp->snd_cwnd < tp->snd_cwnd_clamp)
-                        tp->snd_cwnd++;
-        } else {
+        if (tp->snd_cwnd <= tp->snd_ssthresh)
+                tcp_slow_start(tp);
+        else {
                 /* Update AIMD parameters */
                 if (tp->snd_cwnd > hstcp_aimd_vals[ca->ai].cwnd) {
                         while (tp->snd_cwnd > hstcp_aimd_vals[ca->ai].cwnd &&
diff --git a/net/ipv4/tcp_htcp.c b/net/ipv4/tcp_htcp.c
index e47b37984e95..3284cfb993e6 100644
--- a/net/ipv4/tcp_htcp.c
+++ b/net/ipv4/tcp_htcp.c
@@ -207,14 +207,13 @@ static void htcp_cong_avoid(struct sock *sk, u32 ack, u32 rtt,
         struct tcp_sock *tp = tcp_sk(sk);
         struct htcp *ca = inet_csk_ca(sk);
 
-        if (in_flight < tp->snd_cwnd)
+        if (!tcp_is_cwnd_limited(sk, in_flight))
                 return;
 
-        if (tp->snd_cwnd <= tp->snd_ssthresh) {
-                /* In "safe" area, increase. */
-                if (tp->snd_cwnd < tp->snd_cwnd_clamp)
-                        tp->snd_cwnd++;
-        } else {
+        if (tp->snd_cwnd <= tp->snd_ssthresh)
+                tcp_slow_start(tp);
+        else {
+
                 measure_rtt(sk);
 
                 /* keep track of number of round-trip times since last backoff event */
@@ -224,7 +223,7 @@ static void htcp_cong_avoid(struct sock *sk, u32 ack, u32 rtt,
                         htcp_alpha_update(ca);
                 }
 
-                /* In dangerous area, increase slowly.
+                /* In dangerous area, increase slowly.
                  * In theory this is tp->snd_cwnd += alpha / tp->snd_cwnd
                  */
                 if ((tp->snd_cwnd_cnt++ * ca->alpha)>>7 >= tp->snd_cwnd) {
diff --git a/net/ipv4/tcp_hybla.c b/net/ipv4/tcp_hybla.c
index 77add63623df..40dbb3877510 100644
--- a/net/ipv4/tcp_hybla.c
+++ b/net/ipv4/tcp_hybla.c
@@ -100,12 +100,12 @@ static void hybla_cong_avoid(struct sock *sk, u32 ack, u32 rtt,
                 ca->minrtt = tp->srtt;
         }
 
+        if (!tcp_is_cwnd_limited(sk, in_flight))
+                return;
+
         if (!ca->hybla_en)
                 return tcp_reno_cong_avoid(sk, ack, rtt, in_flight, flag);
 
-        if (in_flight < tp->snd_cwnd)
-                return;
-
         if (ca->rho == 0)
                 hybla_recalc_param(sk);
 
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index 3e98b57578dc..40a26b7157b4 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -42,7 +42,7 @@
  *              Andi Kleen      :       Moved open_request checking here
  *                                      and process RSTs for open_requests.
  *              Andi Kleen      :       Better prune_queue, and other fixes.
- *              Andrey Savochkin:       Fix RTT measurements in the presnce of
+ *              Andrey Savochkin:       Fix RTT measurements in the presence of
  *                                      timestamps.
  *              Andrey Savochkin:       Check sequence numbers correctly when
  *                                      removing SACKs due to in sequence incoming
@@ -89,6 +89,7 @@ int sysctl_tcp_frto;
 int sysctl_tcp_nometrics_save;
 
 int sysctl_tcp_moderate_rcvbuf = 1;
+int sysctl_tcp_abc = 1;
 
 #define FLAG_DATA               0x01 /* Incoming frame contained data.          */
 #define FLAG_WIN_UPDATE         0x02 /* Incoming ACK was a window update.       */
@@ -223,7 +224,7 @@ static void tcp_fixup_sndbuf(struct sock *sk)
  *   of receiver window. Check #2.
  *
  * The scheme does not work when sender sends good segments opening
- * window and then starts to feed us spagetti. But it should work
+ * window and then starts to feed us spaghetti. But it should work
  * in common situations. Otherwise, we have to rely on queue collapsing.
  */
 
@@ -233,7 +234,7 @@ static int __tcp_grow_window(const struct sock *sk, struct tcp_sock *tp,
 {
         /* Optimize this! */
         int truesize = tcp_win_from_space(skb->truesize)/2;
-        int window = tcp_full_space(sk)/2;
+        int window = tcp_win_from_space(sysctl_tcp_rmem[2])/2;
 
         while (tp->rcv_ssthresh <= window) {
                 if (truesize <= skb->len)
@@ -277,7 +278,7 @@ static void tcp_fixup_rcvbuf(struct sock *sk)
         int rcvmem = tp->advmss + MAX_TCP_HEADER + 16 + sizeof(struct sk_buff);
 
         /* Try to select rcvbuf so that 4 mss-sized segments
-         * will fit to window and correspoding skbs will fit to our rcvbuf.
+         * will fit to window and corresponding skbs will fit to our rcvbuf.
          * (was 3; 4 is minimum to allow fast retransmit to work.)
          */
         while (tcp_win_from_space(rcvmem) < tp->advmss)
@@ -286,7 +287,7 @@ static void tcp_fixup_rcvbuf(struct sock *sk)
                 sk->sk_rcvbuf = min(4 * rcvmem, sysctl_tcp_rmem[2]);
 }
 
-/* 4. Try to fixup all. It is made iimediately after connection enters
+/* 4. Try to fixup all. It is made immediately after connection enters
  *    established state.
  */
 static void tcp_init_buffer_space(struct sock *sk)
@@ -326,37 +327,18 @@ static void tcp_init_buffer_space(struct sock *sk)
 static void tcp_clamp_window(struct sock *sk, struct tcp_sock *tp)
 {
         struct inet_connection_sock *icsk = inet_csk(sk);
-        struct sk_buff *skb;
-        unsigned int app_win = tp->rcv_nxt - tp->copied_seq;
-        int ofo_win = 0;
 
         icsk->icsk_ack.quick = 0;
 
-        skb_queue_walk(&tp->out_of_order_queue, skb) {
-                ofo_win += skb->len;
-        }
-
-        /* If overcommit is due to out of order segments,
-         * do not clamp window. Try to expand rcvbuf instead.
-         */
-        if (ofo_win) {
-                if (sk->sk_rcvbuf < sysctl_tcp_rmem[2] &&
-                    !(sk->sk_userlocks & SOCK_RCVBUF_LOCK) &&
-                    !tcp_memory_pressure &&
-                    atomic_read(&tcp_memory_allocated) < sysctl_tcp_mem[0])
-                        sk->sk_rcvbuf = min(atomic_read(&sk->sk_rmem_alloc),
-                                            sysctl_tcp_rmem[2]);
+        if (sk->sk_rcvbuf < sysctl_tcp_rmem[2] &&
+            !(sk->sk_userlocks & SOCK_RCVBUF_LOCK) &&
+            !tcp_memory_pressure &&
+            atomic_read(&tcp_memory_allocated) < sysctl_tcp_mem[0]) {
+                sk->sk_rcvbuf = min(atomic_read(&sk->sk_rmem_alloc),
+                                    sysctl_tcp_rmem[2]);
         }
-        if (atomic_read(&sk->sk_rmem_alloc) > sk->sk_rcvbuf) {
-                app_win += ofo_win;
-                if (atomic_read(&sk->sk_rmem_alloc) >= 2 * sk->sk_rcvbuf)
-                        app_win >>= 1;
-                if (app_win > icsk->icsk_ack.rcv_mss)
-                        app_win -= icsk->icsk_ack.rcv_mss;
-                app_win = max(app_win, 2U*tp->advmss);
-
+        if (atomic_read(&sk->sk_rmem_alloc) > sk->sk_rcvbuf)
                 tp->rcv_ssthresh = min(tp->window_clamp, 2U*tp->advmss);
-        }
 }
 
 /* Receiver "autotuning" code.
@@ -385,8 +367,8 @@ static void tcp_rcv_rtt_update(struct tcp_sock *tp, u32 sample, int win_dep)
                  * are stalled on filesystem I/O.
                  *
                  * Also, since we are only going for a minimum in the
-                 * non-timestamp case, we do not smoothe things out
-                 * else with timestamps disabled convergance takes too
+                 * non-timestamp case, we do not smoother things out
+                 * else with timestamps disabled convergence takes too
                  * long.
                  */
                 if (!win_dep) {
@@ -395,7 +377,7 @@ static void tcp_rcv_rtt_update(struct tcp_sock *tp, u32 sample, int win_dep)
                 } else if (m < new_sample)
                         new_sample = m << 3;
         } else {
-                /* No previous mesaure. */
+                /* No previous measure. */
                 new_sample = m << 3;
         }
 
@@ -524,7 +506,7 @@ static void tcp_event_data_recv(struct sock *sk, struct tcp_sock *tp, struct sk_
                         if (icsk->icsk_ack.ato > icsk->icsk_rto)
                                 icsk->icsk_ack.ato = icsk->icsk_rto;
                 } else if (m > icsk->icsk_rto) {
-                        /* Too long gap. Apparently sender falled to
+                        /* Too long gap. Apparently sender failed to
                          * restart window, so that we send ACKs quickly.
                          */
                         tcp_incr_quickack(sk);
@@ -548,10 +530,9 @@ static void tcp_event_data_recv(struct sock *sk, struct tcp_sock *tp, struct sk_
  * To save cycles in the RFC 1323 implementation it was better to break
  * it up into three procedures. -- erics
  */
-static void tcp_rtt_estimator(struct sock *sk, const __u32 mrtt, u32 *usrtt)
+static void tcp_rtt_estimator(struct sock *sk, const __u32 mrtt)
 {
         struct tcp_sock *tp = tcp_sk(sk);
-        const struct inet_connection_sock *icsk = inet_csk(sk);
         long m = mrtt; /* RTT */
 
         /*      The following amusing code comes from Jacobson's
@@ -565,7 +546,7 @@ static void tcp_rtt_estimator(struct sock *sk, const __u32 mrtt, u32 *usrtt)
          *
          * Funny. This algorithm seems to be very broken.
          * These formulae increase RTO, when it should be decreased, increase
-         * too slowly, when it should be incresed fastly, decrease too fastly
+         * too slowly, when it should be increased fastly, decrease too fastly
          * etc. I guess in BSD RTO takes ONE value, so that it is absolutely
          * does not matter how to _calculate_ it. Seems, it was trap
          * that VJ failed to avoid. 8)
@@ -610,9 +591,6 @@ static void tcp_rtt_estimator(struct sock *sk, const __u32 mrtt, u32 *usrtt)
                 tp->mdev_max = tp->rttvar = max(tp->mdev, TCP_RTO_MIN);
                 tp->rtt_seq = tp->snd_nxt;
         }
-
-        if (icsk->icsk_ca_ops->rtt_sample)
-                icsk->icsk_ca_ops->rtt_sample(sk, *usrtt);
 }
 
 /* Calculate rto without backoff.  This is the second half of Van Jacobson's
@@ -629,14 +607,14 @@ static inline void tcp_set_rto(struct sock *sk)
          *    at least by solaris and freebsd. "Erratic ACKs" has _nothing_
          *    to do with delayed acks, because at cwnd>2 true delack timeout
          *    is invisible. Actually, Linux-2.4 also generates erratic
-         *    ACKs in some curcumstances.
+         *    ACKs in some circumstances.
          */
         inet_csk(sk)->icsk_rto = (tp->srtt >> 3) + tp->rttvar;
 
         /* 2. Fixups made earlier cannot be right.
          *    If we do not estimate RTO correctly without them,
          *    all the algo is pure shit and should be replaced
-         *    with correct one. It is exaclty, which we pretend to do.
+         *    with correct one. It is exactly, which we pretend to do.
          */
 }
 
@@ -794,7 +772,7 @@ static void tcp_init_metrics(struct sock *sk)
          * to make it more realistic.
          *
          * A bit of theory. RTT is time passed after "normal" sized packet
-         * is sent until it is ACKed. In normal curcumstances sending small
+         * is sent until it is ACKed. In normal circumstances sending small
          * packets force peer to delay ACKs and calculation is correct too.
          * The algorithm is adaptive and, provided we follow specs, it
          * NEVER underestimate RTT. BUT! If peer tries to make some clever
@@ -919,18 +897,32 @@ tcp_sacktag_write_queue(struct sock *sk, struct sk_buff *ack_skb, u32 prior_snd_
         int prior_fackets;
         u32 lost_retrans = 0;
         int flag = 0;
+        int dup_sack = 0;
         int i;
 
         if (!tp->sacked_out)
                 tp->fackets_out = 0;
         prior_fackets = tp->fackets_out;
 
-        for (i=0; i<num_sacks; i++, sp++) {
-                struct sk_buff *skb;
-                __u32 start_seq = ntohl(sp->start_seq);
-                __u32 end_seq = ntohl(sp->end_seq);
-                int fack_count = 0;
-                int dup_sack = 0;
+        /* SACK fastpath:
+         * if the only SACK change is the increase of the end_seq of
+         * the first block then only apply that SACK block
+         * and use retrans queue hinting otherwise slowpath */
+        flag = 1;
+        for (i = 0; i< num_sacks; i++) {
+                __u32 start_seq = ntohl(sp[i].start_seq);
+                __u32 end_seq =  ntohl(sp[i].end_seq);
+
+                if (i == 0){
+                        if (tp->recv_sack_cache[i].start_seq != start_seq)
+                                flag = 0;
+                } else {
+                        if ((tp->recv_sack_cache[i].start_seq != start_seq) ||
+                            (tp->recv_sack_cache[i].end_seq != end_seq))
+                                flag = 0;
+                }
+                tp->recv_sack_cache[i].start_seq = start_seq;
+                tp->recv_sack_cache[i].end_seq = end_seq;
 
                 /* Check for D-SACK. */
                 if (i == 0) {
@@ -962,15 +954,58 @@ tcp_sacktag_write_queue(struct sock *sk, struct sk_buff *ack_skb, u32 prior_snd_
                         if (before(ack, prior_snd_una - tp->max_window))
                                 return 0;
                 }
+        }
+
+        if (flag)
+                num_sacks = 1;
+        else {
+                int j;
+                tp->fastpath_skb_hint = NULL;
+
+                /* order SACK blocks to allow in order walk of the retrans queue */
+                for (i = num_sacks-1; i > 0; i--) {
+                        for (j = 0; j < i; j++){
+                                if (after(ntohl(sp[j].start_seq),
+                                          ntohl(sp[j+1].start_seq))){
+                                        sp[j].start_seq = htonl(tp->recv_sack_cache[j+1].start_seq);
+                                        sp[j].end_seq = htonl(tp->recv_sack_cache[j+1].end_seq);
+                                        sp[j+1].start_seq = htonl(tp->recv_sack_cache[j].start_seq);
+                                        sp[j+1].end_seq = htonl(tp->recv_sack_cache[j].end_seq);
+                                }
+
+                        }
+                }
+        }
+
+        /* clear flag as used for different purpose in following code */
+        flag = 0;
+
+        for (i=0; i<num_sacks; i++, sp++) {
+                struct sk_buff *skb;
+                __u32 start_seq = ntohl(sp->start_seq);
+                __u32 end_seq = ntohl(sp->end_seq);
+                int fack_count;
+
+                /* Use SACK fastpath hint if valid */
+                if (tp->fastpath_skb_hint) {
+                        skb = tp->fastpath_skb_hint;
+                        fack_count = tp->fastpath_cnt_hint;
+                } else {
+                        skb = sk->sk_write_queue.next;
+                        fack_count = 0;
+                }
 
                 /* Event "B" in the comment above. */
                 if (after(end_seq, tp->high_seq))
                         flag |= FLAG_DATA_LOST;
 
-                sk_stream_for_retrans_queue(skb, sk) {
+                sk_stream_for_retrans_queue_from(skb, sk) {
                         int in_sack, pcount;
                         u8 sacked;
 
+                        tp->fastpath_skb_hint = skb;
+                        tp->fastpath_cnt_hint = fack_count;
+
                         /* The retransmission queue is always in order, so
                          * we can short-circuit the walk early.
                          */
@@ -1045,6 +1080,9 @@ tcp_sacktag_write_queue(struct sock *sk, struct sk_buff *ack_skb, u32 prior_snd_
                                                 TCP_SKB_CB(skb)->sacked &= ~(TCPCB_LOST|TCPCB_SACKED_RETRANS);
                                                 tp->lost_out -= tcp_skb_pcount(skb);
                                                 tp->retrans_out -= tcp_skb_pcount(skb);
+
+                                                /* clear lost hint */
+                                                tp->retransmit_skb_hint = NULL;
                                         }
                                 } else {
                                         /* New sack for not retransmitted frame,
@@ -1057,6 +1095,9 @@ tcp_sacktag_write_queue(struct sock *sk, struct sk_buff *ack_skb, u32 prior_snd_
                                         if (sacked & TCPCB_LOST) {
                                                 TCP_SKB_CB(skb)->sacked &= ~TCPCB_LOST;
                                                 tp->lost_out -= tcp_skb_pcount(skb);
+
+                                                /* clear lost hint */
+                                                tp->retransmit_skb_hint = NULL;
                                         }
                                 }
 
@@ -1080,6 +1121,7 @@ tcp_sacktag_write_queue(struct sock *sk, struct sk_buff *ack_skb, u32 prior_snd_
                             (TCP_SKB_CB(skb)->sacked&TCPCB_SACKED_RETRANS)) {
                                 TCP_SKB_CB(skb)->sacked &= ~TCPCB_SACKED_RETRANS;
                                 tp->retrans_out -= tcp_skb_pcount(skb);
+                                tp->retransmit_skb_hint = NULL;
                         }
                 }
         }
@@ -1107,6 +1149,9 @@ tcp_sacktag_write_queue(struct sock *sk, struct sk_buff *ack_skb, u32 prior_snd_
                                 TCP_SKB_CB(skb)->sacked &= ~TCPCB_SACKED_RETRANS;
                                 tp->retrans_out -= tcp_skb_pcount(skb);
 
+                                /* clear lost hint */
+                                tp->retransmit_skb_hint = NULL;
+
                                 if (!(TCP_SKB_CB(skb)->sacked&(TCPCB_LOST|TCPCB_SACKED_ACKED))) {
                                         tp->lost_out += tcp_skb_pcount(skb);
                                         TCP_SKB_CB(skb)->sacked |= TCPCB_LOST;
@@ -1214,6 +1259,8 @@ static void tcp_enter_frto_loss(struct sock *sk)
         tcp_set_ca_state(sk, TCP_CA_Loss);
         tp->high_seq = tp->frto_highmark;
         TCP_ECN_queue_cwr(tp);
+
+        clear_all_retrans_hints(tp);
 }
 
 void tcp_clear_retrans(struct tcp_sock *tp)
@@ -1251,6 +1298,7 @@ void tcp_enter_loss(struct sock *sk, int how)
         tp->snd_cwnd_cnt   = 0;
         tp->snd_cwnd_stamp = tcp_time_stamp;
 
+        tp->bytes_acked = 0;
         tcp_clear_retrans(tp);
 
         /* Push undo marker, if it was plain RTO and nothing
@@ -1279,6 +1327,8 @@ void tcp_enter_loss(struct sock *sk, int how)
         tcp_set_ca_state(sk, TCP_CA_Loss);
         tp->high_seq = tp->snd_nxt;
         TCP_ECN_queue_cwr(tp);
+
+        clear_all_retrans_hints(tp);
 }
 
 static int tcp_check_sack_reneging(struct sock *sk)
@@ -1503,17 +1553,37 @@ static void tcp_mark_head_lost(struct sock *sk, struct tcp_sock *tp,
                                int packets, u32 high_seq)
 {
         struct sk_buff *skb;
-        int cnt = packets;
+        int cnt;
 
-        BUG_TRAP(cnt <= tp->packets_out);
+        BUG_TRAP(packets <= tp->packets_out);
+        if (tp->lost_skb_hint) {
+                skb = tp->lost_skb_hint;
+                cnt = tp->lost_cnt_hint;
+        } else {
+                skb = sk->sk_write_queue.next;
+                cnt = 0;
+        }
 
-        sk_stream_for_retrans_queue(skb, sk) {
-                cnt -= tcp_skb_pcount(skb);
-                if (cnt < 0 || after(TCP_SKB_CB(skb)->end_seq, high_seq))
+        sk_stream_for_retrans_queue_from(skb, sk) {
+                /* TODO: do this better */
+                /* this is not the most efficient way to do this... */
+                tp->lost_skb_hint = skb;
+                tp->lost_cnt_hint = cnt;
+                cnt += tcp_skb_pcount(skb);
+                if (cnt > packets || after(TCP_SKB_CB(skb)->end_seq, high_seq))
                         break;
                 if (!(TCP_SKB_CB(skb)->sacked&TCPCB_TAGBITS)) {
                         TCP_SKB_CB(skb)->sacked |= TCPCB_LOST;
                         tp->lost_out += tcp_skb_pcount(skb);
+
+                        /* clear xmit_retransmit_queue hints
+                         *  if this is beyond hint */
+                        if(tp->retransmit_skb_hint != NULL &&
+                           before(TCP_SKB_CB(skb)->seq,
+                                  TCP_SKB_CB(tp->retransmit_skb_hint)->seq)) {
+
+                                tp->retransmit_skb_hint = NULL;
+                        }
                 }
         }
         tcp_sync_left_out(tp);
@@ -1540,13 +1610,28 @@ static void tcp_update_scoreboard(struct sock *sk, struct tcp_sock *tp)
         if (tcp_head_timedout(sk, tp)) {
                 struct sk_buff *skb;
 
-                sk_stream_for_retrans_queue(skb, sk) {
-                        if (tcp_skb_timedout(sk, skb) &&
-                            !(TCP_SKB_CB(skb)->sacked&TCPCB_TAGBITS)) {
+                skb = tp->scoreboard_skb_hint ? tp->scoreboard_skb_hint
+                        : sk->sk_write_queue.next;
+
+                sk_stream_for_retrans_queue_from(skb, sk) {
+                        if (!tcp_skb_timedout(sk, skb))
+                                break;
+
+                        if (!(TCP_SKB_CB(skb)->sacked&TCPCB_TAGBITS)) {
                                 TCP_SKB_CB(skb)->sacked |= TCPCB_LOST;
                                 tp->lost_out += tcp_skb_pcount(skb);
+
+                                /* clear xmit_retrans hint */
+                                if (tp->retransmit_skb_hint &&
+                                    before(TCP_SKB_CB(skb)->seq,
+                                           TCP_SKB_CB(tp->retransmit_skb_hint)->seq))
+
+                                        tp->retransmit_skb_hint = NULL;
                         }
                 }
+
+                tp->scoreboard_skb_hint = skb;
+
                 tcp_sync_left_out(tp);
         }
 }
@@ -1626,6 +1711,10 @@ static void tcp_undo_cwr(struct sock *sk, const int undo)
         }
         tcp_moderate_cwnd(tp);
         tp->snd_cwnd_stamp = tcp_time_stamp;
+
+        /* There is something screwy going on with the retrans hints after
+           an undo */
+        clear_all_retrans_hints(tp);
 }
 
 static inline int tcp_may_undo(struct tcp_sock *tp)
@@ -1709,6 +1798,9 @@ static int tcp_try_undo_loss(struct sock *sk, struct tcp_sock *tp)
                 sk_stream_for_retrans_queue(skb, sk) {
                         TCP_SKB_CB(skb)->sacked &= ~TCPCB_LOST;
                 }
+
+                clear_all_retrans_hints(tp);
+
                 DBGUNDO(sk, tp, "partial loss");
                 tp->lost_out = 0;
                 tp->left_out = tp->sacked_out;
@@ -1908,6 +2000,7 @@ tcp_fastretrans_alert(struct sock *sk, u32 prior_snd_una,
                         TCP_ECN_queue_cwr(tp);
                 }
 
+                tp->bytes_acked = 0;
                 tp->snd_cwnd_cnt = 0;
                 tcp_set_ca_state(sk, TCP_CA_Recovery);
         }
@@ -1919,9 +2012,9 @@ tcp_fastretrans_alert(struct sock *sk, u32 prior_snd_una,
 }
 
 /* Read draft-ietf-tcplw-high-performance before mucking
- * with this code. (Superceeds RFC1323)
+ * with this code. (Supersedes RFC1323)
  */
-static void tcp_ack_saw_tstamp(struct sock *sk, u32 *usrtt, int flag)
+static void tcp_ack_saw_tstamp(struct sock *sk, int flag)
 {
         /* RTTM Rule: A TSecr value received in a segment is used to
          * update the averaged RTT measurement only if the segment
@@ -1932,7 +2025,7 @@ static void tcp_ack_saw_tstamp(struct sock *sk, u32 *usrtt, int flag)
          * 1998/04/10 Andrey V. Savochkin <saw@msu.ru>
          *
          * Changed: reset backoff as soon as we see the first valid sample.
-         * If we do not, we get strongly overstimated rto. With timestamps
+         * If we do not, we get strongly overestimated rto. With timestamps
          * samples are accepted even from very old segments: f.e., when rtt=1
          * increases to 8, we retransmit 5 times and after 8 seconds delayed
          * answer arrives rto becomes 120 seconds! If at least one of segments
@@ -1940,13 +2033,13 @@ static void tcp_ack_saw_tstamp(struct sock *sk, u32 *usrtt, int flag)
          */
         struct tcp_sock *tp = tcp_sk(sk);
         const __u32 seq_rtt = tcp_time_stamp - tp->rx_opt.rcv_tsecr;
-        tcp_rtt_estimator(sk, seq_rtt, usrtt);
+        tcp_rtt_estimator(sk, seq_rtt);
         tcp_set_rto(sk);
         inet_csk(sk)->icsk_backoff = 0;
         tcp_bound_rto(sk);
 }
 
-static void tcp_ack_no_tstamp(struct sock *sk, u32 seq_rtt, u32 *usrtt, int flag)
+static void tcp_ack_no_tstamp(struct sock *sk, u32 seq_rtt, int flag)
 {
         /* We don't have a timestamp. Can only use
          * packets that are not retransmitted to determine
@@ -1960,21 +2053,21 @@ static void tcp_ack_no_tstamp(struct sock *sk, u32 seq_rtt, u32 *usrtt, int flag
         if (flag & FLAG_RETRANS_DATA_ACKED)
                 return;
 
-        tcp_rtt_estimator(sk, seq_rtt, usrtt);
+        tcp_rtt_estimator(sk, seq_rtt);
         tcp_set_rto(sk);
         inet_csk(sk)->icsk_backoff = 0;
         tcp_bound_rto(sk);
 }
 
 static inline void tcp_ack_update_rtt(struct sock *sk, const int flag,
-                                      const s32 seq_rtt, u32 *usrtt)
+                                      const s32 seq_rtt)
 {
         const struct tcp_sock *tp = tcp_sk(sk);
         /* Note that peer MAY send zero echo. In this case it is ignored. (rfc1323) */
         if (tp->rx_opt.saw_tstamp && tp->rx_opt.rcv_tsecr)
-                tcp_ack_saw_tstamp(sk, usrtt, flag);
+                tcp_ack_saw_tstamp(sk, flag);
         else if (seq_rtt >= 0)
-                tcp_ack_no_tstamp(sk, seq_rtt, usrtt, flag);
+                tcp_ack_no_tstamp(sk, seq_rtt, flag);
 }
 
 static inline void tcp_cong_avoid(struct sock *sk, u32 ack, u32 rtt,
@@ -2054,20 +2147,27 @@ static int tcp_tso_acked(struct sock *sk, struct sk_buff *skb,
         return acked;
 }
 
+static inline u32 tcp_usrtt(const struct sk_buff *skb)
+{
+        struct timeval tv, now;
+
+        do_gettimeofday(&now);
+        skb_get_timestamp(skb, &tv);
+        return (now.tv_sec - tv.tv_sec) * 1000000 + (now.tv_usec - tv.tv_usec);
+}
 
 /* Remove acknowledged frames from the retransmission queue. */
-static int tcp_clean_rtx_queue(struct sock *sk, __s32 *seq_rtt_p, s32 *seq_usrtt)
+static int tcp_clean_rtx_queue(struct sock *sk, __s32 *seq_rtt_p)
 {
         struct tcp_sock *tp = tcp_sk(sk);
+        const struct inet_connection_sock *icsk = inet_csk(sk);
         struct sk_buff *skb;
         __u32 now = tcp_time_stamp;
         int acked = 0;
         __s32 seq_rtt = -1;
-        struct timeval usnow;
         u32 pkts_acked = 0;
-
-        if (seq_usrtt)
-                do_gettimeofday(&usnow);
+        void (*rtt_sample)(struct sock *sk, u32 usrtt)
+                = icsk->icsk_ca_ops->rtt_sample;
 
         while ((skb = skb_peek(&sk->sk_write_queue)) &&
                skb != sk->sk_send_head) {
@@ -2107,16 +2207,11 @@ static int tcp_clean_rtx_queue(struct sock *sk, __s32 *seq_rtt_p, s32 *seq_usrtt
                                         tp->retrans_out -= tcp_skb_pcount(skb);
                                 acked |= FLAG_RETRANS_DATA_ACKED;
                                 seq_rtt = -1;
-                        } else if (seq_rtt < 0)
+                        } else if (seq_rtt < 0) {
                                 seq_rtt = now - scb->when;
-                        if (seq_usrtt) {
-                                struct timeval tv;
-                        
-                                skb_get_timestamp(skb, &tv);
-                                *seq_usrtt = (usnow.tv_sec - tv.tv_sec) * 1000000
-                                        + (usnow.tv_usec - tv.tv_usec);
+                                if (rtt_sample)
+                                        (*rtt_sample)(sk, tcp_usrtt(skb));
                         }
-
                         if (sacked & TCPCB_SACKED_ACKED)
                                 tp->sacked_out -= tcp_skb_pcount(skb);
                         if (sacked & TCPCB_LOST)
@@ -2126,17 +2221,20 @@ static int tcp_clean_rtx_queue(struct sock *sk, __s32 *seq_rtt_p, s32 *seq_usrtt
                                     !before(scb->end_seq, tp->snd_up))
                                         tp->urg_mode = 0;
                         }
-                } else if (seq_rtt < 0)
+                } else if (seq_rtt < 0) {
                         seq_rtt = now - scb->when;
+                        if (rtt_sample)
+                                (*rtt_sample)(sk, tcp_usrtt(skb));
+                }
                 tcp_dec_pcount_approx(&tp->fackets_out, skb);
                 tcp_packets_out_dec(tp, skb);
                 __skb_unlink(skb, &sk->sk_write_queue);
                 sk_stream_free_skb(sk, skb);
+                clear_all_retrans_hints(tp);
         }
 
         if (acked&FLAG_ACKED) {
-                const struct inet_connection_sock *icsk = inet_csk(sk);
-                tcp_ack_update_rtt(sk, acked, seq_rtt, seq_usrtt);
+                tcp_ack_update_rtt(sk, acked, seq_rtt);
                 tcp_ack_packets_out(sk, tp);
 
                 if (icsk->icsk_ca_ops->pkts_acked)
@@ -2284,7 +2382,7 @@ static void tcp_process_frto(struct sock *sk, u32 prior_snd_una)
         }
 
         /* F-RTO affects on two new ACKs following RTO.
-         * At latest on third ACK the TCP behavor is back to normal.
+         * At latest on third ACK the TCP behavior is back to normal.
          */
         tp->frto_counter = (tp->frto_counter + 1) % 3;
 }
@@ -2299,7 +2397,6 @@ static int tcp_ack(struct sock *sk, struct sk_buff *skb, int flag)
         u32 ack = TCP_SKB_CB(skb)->ack_seq;
         u32 prior_in_flight;
         s32 seq_rtt;
-        s32 seq_usrtt = 0;
         int prior_packets;
 
         /* If the ack is newer than sent or older than previous acks
@@ -2311,6 +2408,9 @@ static int tcp_ack(struct sock *sk, struct sk_buff *skb, int flag)
         if (before(ack, prior_snd_una))
                 goto old_ack;
 
+        if (sysctl_tcp_abc && icsk->icsk_ca_state < TCP_CA_CWR)
+                tp->bytes_acked += ack - prior_snd_una;
+
         if (!(flag&FLAG_SLOWPATH) && after(ack, prior_snd_una)) {
                 /* Window is constant, pure forward advance.
                  * No more checks are required.
@@ -2352,14 +2452,13 @@ static int tcp_ack(struct sock *sk, struct sk_buff *skb, int flag)
         prior_in_flight = tcp_packets_in_flight(tp);
 
         /* See if we can take anything off of the retransmit queue. */
-        flag |= tcp_clean_rtx_queue(sk, &seq_rtt,
-                                    icsk->icsk_ca_ops->rtt_sample ? &seq_usrtt : NULL);
+        flag |= tcp_clean_rtx_queue(sk, &seq_rtt);
 
         if (tp->frto_counter)
                 tcp_process_frto(sk, prior_snd_una);
 
         if (tcp_ack_is_dubious(sk, flag)) {
-                /* Advanve CWND, if state allows this. */
+                /* Advance CWND, if state allows this. */
                 if ((flag & FLAG_DATA_ACKED) && tcp_may_raise_cwnd(sk, flag))
                         tcp_cong_avoid(sk, ack,  seq_rtt, prior_in_flight, 0);
                 tcp_fastretrans_alert(sk, prior_snd_una, prior_packets, flag);
@@ -3148,7 +3247,7 @@ tcp_collapse(struct sock *sk, struct sk_buff_head *list,
 {
         struct sk_buff *skb;
 
-        /* First, check that queue is collapsable and find
+        /* First, check that queue is collapsible and find
          * the point where collapsing can be useful. */
         for (skb = head; skb != tail; ) {
                 /* No new bits? It is possible on ofo queue. */
@@ -3456,7 +3555,7 @@ static __inline__ void tcp_ack_snd_check(struct sock *sk)
 
 /*
  *      This routine is only called when we have urgent data
- *      signalled. Its the 'slow' part of tcp_urg. It could be
+ *      signaled. Its the 'slow' part of tcp_urg. It could be
  *      moved inline now as tcp_urg is only called from one
  *      place. We handle URGent data wrong. We have to - as
  *      BSD still doesn't use the correction from RFC961.
@@ -3501,7 +3600,7 @@ static void tcp_check_urg(struct sock * sk, struct tcphdr * th)
          * urgent. To do this requires some care. We cannot just ignore
          * tp->copied_seq since we would read the last urgent byte again
          * as data, nor can we alter copied_seq until this data arrives
-         * or we break the sematics of SIOCATMARK (and thus sockatmark())
+         * or we break the semantics of SIOCATMARK (and thus sockatmark())
          *
          * NOTE. Double Dutch. Rendering to plain English: author of comment
          * above did something sort of  send("A", MSG_OOB); send("B", MSG_OOB);
@@ -3646,7 +3745,7 @@ int tcp_rcv_established(struct sock *sk, struct sk_buff *skb,
         tp->rx_opt.saw_tstamp = 0;
 
         /*      pred_flags is 0xS?10 << 16 + snd_wnd
-         *      if header_predition is to be made
+         *      if header_prediction is to be made
          *      'S' will always be tp->tcp_header_len >> 2
          *      '?' will be 0 for the fast path, otherwise pred_flags is 0 to
          *  turn it off (when there are holes in the receive 
@@ -4242,7 +4341,7 @@ int tcp_rcv_state_process(struct sock *sk, struct sk_buff *skb,
                                  */
                                 if (tp->rx_opt.saw_tstamp && tp->rx_opt.rcv_tsecr &&
                                     !tp->srtt)
-                                        tcp_ack_saw_tstamp(sk, NULL, 0);
+                                        tcp_ack_saw_tstamp(sk, 0);
 
                                 if (tp->rx_opt.tstamp_ok)
                                         tp->advmss -= TCPOLEN_TSTAMP_ALIGNED;
@@ -4372,6 +4471,7 @@ discard:
 
 EXPORT_SYMBOL(sysctl_tcp_ecn);
 EXPORT_SYMBOL(sysctl_tcp_reordering);
+EXPORT_SYMBOL(sysctl_tcp_abc);
 EXPORT_SYMBOL(tcp_parse_options);
 EXPORT_SYMBOL(tcp_rcv_established);
 EXPORT_SYMBOL(tcp_rcv_state_process);
diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index ac1fcf5b4ebc..4d5021e1929b 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -39,7 +39,7 @@
  *                                      request_sock handling and moved
  *                                      most of it into the af independent code.
  *                                      Added tail drop and some other bugfixes.
- *                                      Added new listen sematics.
+ *                                      Added new listen semantics.
  *              Mike McLagan    :       Routing by source
  *      Juan Jose Ciarlante:            ip_dynaddr bits
  *              Andi Kleen:             various fixes.
@@ -1210,7 +1210,7 @@ int tcp_v4_rcv(struct sk_buff *skb)
 
         /* An explanation is required here, I think.
          * Packet length and doff are validated by header prediction,
-         * provided case of th->doff==0 is elimineted.
+         * provided case of th->doff==0 is eliminated.
          * So, we defer the checks. */
         if ((skb->ip_summed != CHECKSUM_UNNECESSARY &&
              tcp_v4_checksum_init(skb)))
diff --git a/net/ipv4/tcp_minisocks.c b/net/ipv4/tcp_minisocks.c
index b1a63b2c6b4a..1b66a2ac4321 100644
--- a/net/ipv4/tcp_minisocks.c
+++ b/net/ipv4/tcp_minisocks.c
@@ -158,7 +158,7 @@ kill_with_rst:
                 /* I am shamed, but failed to make it more elegant.
                  * Yes, it is direct reference to IP, which is impossible
                  * to generalize to IPv6. Taking into account that IPv6
-                 * do not undertsnad recycling in any case, it not
+                 * do not understand recycling in any case, it not
                  * a big problem in practice. --ANK */
                 if (tw->tw_family == AF_INET &&
                     tcp_death_row.sysctl_tw_recycle && tcptw->tw_ts_recent_stamp &&
@@ -194,7 +194,7 @@ kill_with_rst:
                 /* In window segment, it may be only reset or bare ack. */
 
                 if (th->rst) {
-                        /* This is TIME_WAIT assasination, in two flavors.
+                        /* This is TIME_WAIT assassination, in two flavors.
                          * Oh well... nobody has a sufficient solution to this
                          * protocol bug yet.
                          */
@@ -380,6 +380,7 @@ struct sock *tcp_create_openreq_child(struct sock *sk, struct request_sock *req,
                  */
                 newtp->snd_cwnd = 2;
                 newtp->snd_cwnd_cnt = 0;
+                newtp->bytes_acked = 0;
 
                 newtp->frto_counter = 0;
                 newtp->frto_highmark = 0;
@@ -550,7 +551,7 @@ struct sock *tcp_check_req(struct sock *sk,struct sk_buff *skb,
 
         /* RFC793 page 36: "If the connection is in any non-synchronized state ...
          *                  and the incoming segment acknowledges something not yet
-         *                  sent (the segment carries an unaccaptable ACK) ...
+         *                  sent (the segment carries an unacceptable ACK) ...
          *                  a reset is sent."
          *
          * Invalid ACK: reset will be sent by listening socket
diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index b907456a79f4..029c70dfb585 100644
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -436,6 +436,8 @@ int tcp_fragment(struct sock *sk, struct sk_buff *skb, u32 len, unsigned int mss
         u16 flags;
 
         BUG_ON(len > skb->len);
+
+        clear_all_retrans_hints(tp);
         nsize = skb_headlen(skb) - len;
         if (nsize < 0)
                 nsize = 0;
@@ -599,7 +601,7 @@ int tcp_trim_head(struct sock *sk, struct sk_buff *skb, u32 len)
    for TCP options, but includes only bare TCP header.
 
    tp->rx_opt.mss_clamp is mss negotiated at connection setup.
-   It is minumum of user_mss and mss received with SYN.
+   It is minimum of user_mss and mss received with SYN.
    It also does not include TCP options.
 
    tp->pmtu_cookie is last pmtu, seen by this function.
@@ -1171,7 +1173,7 @@ u32 __tcp_select_window(struct sock *sk)
 {
         struct inet_connection_sock *icsk = inet_csk(sk);
         struct tcp_sock *tp = tcp_sk(sk);
-        /* MSS for the peer's data.  Previous verions used mss_clamp
+        /* MSS for the peer's data.  Previous versions used mss_clamp
          * here.  I don't know if the value based on our guesses
          * of peer's MSS is better for the performance.  It's more correct
          * but may be worse for the performance because of rcv_mss
@@ -1260,7 +1262,10 @@ static void tcp_retrans_try_collapse(struct sock *sk, struct sk_buff *skb, int m
                 BUG_ON(tcp_skb_pcount(skb) != 1 ||
                        tcp_skb_pcount(next_skb) != 1);
 
-                /* Ok.  We will be able to collapse the packet. */
+                /* changing transmit queue under us so clear hints */
+                clear_all_retrans_hints(tp);
+
+                /* Ok.  We will be able to collapse the packet. */
                 __skb_unlink(next_skb, &sk->sk_write_queue);
 
                 memcpy(skb_put(skb, next_skb_size), next_skb->data, next_skb_size);
@@ -1330,6 +1335,8 @@ void tcp_simple_retransmit(struct sock *sk)
                 }
         }
 
+        clear_all_retrans_hints(tp);
+
         if (!lost)
                 return;
 
@@ -1361,7 +1368,7 @@ int tcp_retransmit_skb(struct sock *sk, struct sk_buff *skb)
         int err;
 
         /* Do not sent more than we queued. 1/4 is reserved for possible
-         * copying overhead: frgagmentation, tunneling, mangling etc.
+         * copying overhead: fragmentation, tunneling, mangling etc.
          */
         if (atomic_read(&sk->sk_wmem_alloc) >
             min(sk->sk_wmem_queued + (sk->sk_wmem_queued >> 2), sk->sk_sndbuf))
@@ -1468,13 +1475,25 @@ void tcp_xmit_retransmit_queue(struct sock *sk)
         const struct inet_connection_sock *icsk = inet_csk(sk);
         struct tcp_sock *tp = tcp_sk(sk);
         struct sk_buff *skb;
-        int packet_cnt = tp->lost_out;
+        int packet_cnt;
+
+        if (tp->retransmit_skb_hint) {
+                skb = tp->retransmit_skb_hint;
+                packet_cnt = tp->retransmit_cnt_hint;
+        }else{
+                skb = sk->sk_write_queue.next;
+                packet_cnt = 0;
+        }
 
         /* First pass: retransmit lost packets. */
-        if (packet_cnt) {
-                sk_stream_for_retrans_queue(skb, sk) {
+        if (tp->lost_out) {
+                sk_stream_for_retrans_queue_from(skb, sk) {
                         __u8 sacked = TCP_SKB_CB(skb)->sacked;
 
+                        /* we could do better than to assign each time */
+                        tp->retransmit_skb_hint = skb;
+                        tp->retransmit_cnt_hint = packet_cnt;
+
                         /* Assume this retransmit will generate
                          * only one packet for congestion window
                          * calculation purposes.  This works because
@@ -1485,10 +1504,12 @@ void tcp_xmit_retransmit_queue(struct sock *sk)
                         if (tcp_packets_in_flight(tp) >= tp->snd_cwnd)
                                 return;
 
-                        if (sacked&TCPCB_LOST) {
+                        if (sacked & TCPCB_LOST) {
                                 if (!(sacked&(TCPCB_SACKED_ACKED|TCPCB_SACKED_RETRANS))) {
-                                        if (tcp_retransmit_skb(sk, skb))
+                                        if (tcp_retransmit_skb(sk, skb)) {
+                                                tp->retransmit_skb_hint = NULL;
                                                 return;
+                                        }
                                         if (icsk->icsk_ca_state != TCP_CA_Loss)
                                                 NET_INC_STATS_BH(LINUX_MIB_TCPFASTRETRANS);
                                         else
@@ -1501,8 +1522,8 @@ void tcp_xmit_retransmit_queue(struct sock *sk)
                                                                           TCP_RTO_MAX);
                                 }
 
-                                packet_cnt -= tcp_skb_pcount(skb);
-                                if (packet_cnt <= 0)
+                                packet_cnt += tcp_skb_pcount(skb);
+                                if (packet_cnt >= tp->lost_out)
                                         break;
                         }
                 }
@@ -1528,9 +1549,18 @@ void tcp_xmit_retransmit_queue(struct sock *sk)
         if (tcp_may_send_now(sk, tp))
                 return;
 
-        packet_cnt = 0;
+        if (tp->forward_skb_hint) {
+                skb = tp->forward_skb_hint;
+                packet_cnt = tp->forward_cnt_hint;
+        } else{
+                skb = sk->sk_write_queue.next;
+                packet_cnt = 0;
+        }
+
+        sk_stream_for_retrans_queue_from(skb, sk) {
+                tp->forward_cnt_hint = packet_cnt;
+                tp->forward_skb_hint = skb;
 
-        sk_stream_for_retrans_queue(skb, sk) {
                 /* Similar to the retransmit loop above we
                  * can pretend that the retransmitted SKB
                  * we send out here will be composed of one
@@ -1547,8 +1577,10 @@ void tcp_xmit_retransmit_queue(struct sock *sk)
                         continue;
 
                 /* Ok, retransmit it. */
-                if (tcp_retransmit_skb(sk, skb))
+                if (tcp_retransmit_skb(sk, skb)) {
+                        tp->forward_skb_hint = NULL;
                         break;
+                }
 
                 if (skb == skb_peek(&sk->sk_write_queue))
                         inet_csk_reset_xmit_timer(sk, ICSK_TIME_RETRANS,
@@ -2058,3 +2090,4 @@ EXPORT_SYMBOL(tcp_connect);
 EXPORT_SYMBOL(tcp_make_synack);
 EXPORT_SYMBOL(tcp_simple_retransmit);
 EXPORT_SYMBOL(tcp_sync_mss);
+EXPORT_SYMBOL(sysctl_tcp_tso_win_divisor);
diff --git a/net/ipv4/tcp_scalable.c b/net/ipv4/tcp_scalable.c
index 327770bf5522..26d7486ee501 100644
--- a/net/ipv4/tcp_scalable.c
+++ b/net/ipv4/tcp_scalable.c
@@ -20,20 +20,20 @@ static void tcp_scalable_cong_avoid(struct sock *sk, u32 ack, u32 rtt,
                                     u32 in_flight, int flag)
 {
         struct tcp_sock *tp = tcp_sk(sk);
-        if (in_flight < tp->snd_cwnd)
+
+        if (!tcp_is_cwnd_limited(sk, in_flight))
                 return;
 
-        if (tp->snd_cwnd <= tp->snd_ssthresh) {
-                tp->snd_cwnd++;
-        } else {
+        if (tp->snd_cwnd <= tp->snd_ssthresh)
+                tcp_slow_start(tp);
+        else {
                 tp->snd_cwnd_cnt++;
                 if (tp->snd_cwnd_cnt > min(tp->snd_cwnd, TCP_SCALABLE_AI_CNT)){
-                        tp->snd_cwnd++;
+                        if (tp->snd_cwnd < tp->snd_cwnd_clamp)
+                                tp->snd_cwnd++;
                         tp->snd_cwnd_cnt = 0;
                 }
         }
-        tp->snd_cwnd = min_t(u32, tp->snd_cwnd, tp->snd_cwnd_clamp);
-        tp->snd_cwnd_stamp = tcp_time_stamp;
 }
 
 static u32 tcp_scalable_ssthresh(struct sock *sk)
diff --git a/net/ipv4/tcp_timer.c b/net/ipv4/tcp_timer.c
index 415ee47ac1c5..e1880959614a 100644
--- a/net/ipv4/tcp_timer.c
+++ b/net/ipv4/tcp_timer.c
@@ -58,7 +58,7 @@ static void tcp_write_err(struct sock *sk)
  * to prevent DoS attacks. It is called when a retransmission timeout
  * or zero probe timeout occurs on orphaned socket.
  *
- * Criterium is still not confirmed experimentally and may change.
+ * Criteria is still not confirmed experimentally and may change.
  * We kill the socket, if:
  * 1. If number of orphaned sockets exceeds an administratively configured
  *    limit.
@@ -132,7 +132,7 @@ static int tcp_write_timeout(struct sock *sk)
                            hole detection. :-(
 
                            It is place to make it. It is not made. I do not want
-                           to make it. It is disguisting. It does not work in any
+                           to make it. It is disgusting. It does not work in any
                            case. Let me to cite the same draft, which requires for
                            us to implement this:
 
diff --git a/net/ipv4/tcp_vegas.c b/net/ipv4/tcp_vegas.c
index 93c5f92070f9..4376814d29fb 100644
--- a/net/ipv4/tcp_vegas.c
+++ b/net/ipv4/tcp_vegas.c
@@ -236,8 +236,7 @@ static void tcp_vegas_cong_avoid(struct sock *sk, u32 ack,
                         /* We don't have enough RTT samples to do the Vegas
                          * calculation, so we'll behave like Reno.
                          */
-                        if (tp->snd_cwnd > tp->snd_ssthresh)
-                                tp->snd_cwnd++;
+                        tcp_reno_cong_avoid(sk, ack, seq_rtt, in_flight, cnt);
                 } else {
                         u32 rtt, target_cwnd, diff;
 
@@ -275,7 +274,7 @@ static void tcp_vegas_cong_avoid(struct sock *sk, u32 ack,
                          */
                         diff = (old_wnd << V_PARAM_SHIFT) - target_cwnd;
 
-                        if (tp->snd_cwnd < tp->snd_ssthresh) {
+                        if (tp->snd_cwnd <= tp->snd_ssthresh) {
                                 /* Slow start.  */
                                 if (diff > gamma) {
                                         /* Going too fast. Time to slow down
@@ -295,6 +294,7 @@ static void tcp_vegas_cong_avoid(struct sock *sk, u32 ack,
                                                             V_PARAM_SHIFT)+1);
 
                                 }
+                                tcp_slow_start(tp);
                         } else {
                                 /* Congestion avoidance. */
                                 u32 next_snd_cwnd;
@@ -327,37 +327,17 @@ static void tcp_vegas_cong_avoid(struct sock *sk, u32 ack,
                                 else if (next_snd_cwnd < tp->snd_cwnd)
                                         tp->snd_cwnd--;
                         }
-                }
 
-                /* Wipe the slate clean for the next RTT. */
-                vegas->cntRTT = 0;
-                vegas->minRTT = 0x7fffffff;
+                        if (tp->snd_cwnd < 2)
+                                tp->snd_cwnd = 2;
+                        else if (tp->snd_cwnd > tp->snd_cwnd_clamp)
+                                tp->snd_cwnd = tp->snd_cwnd_clamp;
+                }
         }
 
-        /* The following code is executed for every ack we receive,
-         * except for conditions checked in should_advance_cwnd()
-         * before the call to tcp_cong_avoid(). Mainly this means that
-         * we only execute this code if the ack actually acked some
-         * data.
-         */
-
-        /* If we are in slow start, increase our cwnd in response to this ACK.
-         * (If we are not in slow start then we are in congestion avoidance,
-         * and adjust our congestion window only once per RTT. See the code
-         * above.)
-         */
-        if (tp->snd_cwnd <= tp->snd_ssthresh)
-                tp->snd_cwnd++;
-
-        /* to keep cwnd from growing without bound */
-        tp->snd_cwnd = min_t(u32, tp->snd_cwnd, tp->snd_cwnd_clamp);
-
-        /* Make sure that we are never so timid as to reduce our cwnd below
-         * 2 MSS.
-         *
-         * Going below 2 MSS would risk huge delayed ACKs from our receiver.
-         */
-        tp->snd_cwnd = max(tp->snd_cwnd, 2U);
+        /* Wipe the slate clean for the next RTT. */
+        vegas->cntRTT = 0;
+        vegas->minRTT = 0x7fffffff;
 }
 
 /* Extract info for Tcp socket info provided via netlink. */