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-rw-r--r--net/ipv4/proc.c9
-rw-r--r--net/ipv4/sysctl_net_ipv4.c3
-rw-r--r--net/ipv4/tcp.c109
-rw-r--r--net/ipv4/tcp_input.c303
-rw-r--r--net/ipv4/tcp_ipv4.c63
-rw-r--r--net/ipv4/tcp_minisocks.c3
-rw-r--r--net/ipv4/tcp_output.c2
-rw-r--r--net/ipv4/tcp_timer.c12
-rw-r--r--net/ipv4/tcp_westwood.c31
-rw-r--r--net/ipv6/tcp_ipv6.c3
10 files changed, 40 insertions, 498 deletions
diff --git a/net/ipv4/proc.c b/net/ipv4/proc.c
index 43eb6567b3a0..b6d3fe03feb3 100644
--- a/net/ipv4/proc.c
+++ b/net/ipv4/proc.c
@@ -206,14 +206,7 @@ static const struct snmp_mib snmp4_net_list[] = {
SNMP_MIB_ITEM("DelayedACKLost", LINUX_MIB_DELAYEDACKLOST),
SNMP_MIB_ITEM("ListenOverflows", LINUX_MIB_LISTENOVERFLOWS),
SNMP_MIB_ITEM("ListenDrops", LINUX_MIB_LISTENDROPS),
- SNMP_MIB_ITEM("TCPPrequeued", LINUX_MIB_TCPPREQUEUED),
- SNMP_MIB_ITEM("TCPDirectCopyFromBacklog", LINUX_MIB_TCPDIRECTCOPYFROMBACKLOG),
- SNMP_MIB_ITEM("TCPDirectCopyFromPrequeue", LINUX_MIB_TCPDIRECTCOPYFROMPREQUEUE),
- SNMP_MIB_ITEM("TCPPrequeueDropped", LINUX_MIB_TCPPREQUEUEDROPPED),
- SNMP_MIB_ITEM("TCPHPHits", LINUX_MIB_TCPHPHITS),
- SNMP_MIB_ITEM("TCPHPHitsToUser", LINUX_MIB_TCPHPHITSTOUSER),
SNMP_MIB_ITEM("TCPPureAcks", LINUX_MIB_TCPPUREACKS),
- SNMP_MIB_ITEM("TCPHPAcks", LINUX_MIB_TCPHPACKS),
SNMP_MIB_ITEM("TCPRenoRecovery", LINUX_MIB_TCPRENORECOVERY),
SNMP_MIB_ITEM("TCPSackRecovery", LINUX_MIB_TCPSACKRECOVERY),
SNMP_MIB_ITEM("TCPSACKReneging", LINUX_MIB_TCPSACKRENEGING),
@@ -230,14 +223,12 @@ static const struct snmp_mib snmp4_net_list[] = {
SNMP_MIB_ITEM("TCPSackFailures", LINUX_MIB_TCPSACKFAILURES),
SNMP_MIB_ITEM("TCPLossFailures", LINUX_MIB_TCPLOSSFAILURES),
SNMP_MIB_ITEM("TCPFastRetrans", LINUX_MIB_TCPFASTRETRANS),
- SNMP_MIB_ITEM("TCPForwardRetrans", LINUX_MIB_TCPFORWARDRETRANS),
SNMP_MIB_ITEM("TCPSlowStartRetrans", LINUX_MIB_TCPSLOWSTARTRETRANS),
SNMP_MIB_ITEM("TCPTimeouts", LINUX_MIB_TCPTIMEOUTS),
SNMP_MIB_ITEM("TCPLossProbes", LINUX_MIB_TCPLOSSPROBES),
SNMP_MIB_ITEM("TCPLossProbeRecovery", LINUX_MIB_TCPLOSSPROBERECOVERY),
SNMP_MIB_ITEM("TCPRenoRecoveryFail", LINUX_MIB_TCPRENORECOVERYFAIL),
SNMP_MIB_ITEM("TCPSackRecoveryFail", LINUX_MIB_TCPSACKRECOVERYFAIL),
- SNMP_MIB_ITEM("TCPSchedulerFailed", LINUX_MIB_TCPSCHEDULERFAILED),
SNMP_MIB_ITEM("TCPRcvCollapsed", LINUX_MIB_TCPRCVCOLLAPSED),
SNMP_MIB_ITEM("TCPDSACKOldSent", LINUX_MIB_TCPDSACKOLDSENT),
SNMP_MIB_ITEM("TCPDSACKOfoSent", LINUX_MIB_TCPDSACKOFOSENT),
diff --git a/net/ipv4/sysctl_net_ipv4.c b/net/ipv4/sysctl_net_ipv4.c
index 9bf809726066..0d3c038d7b04 100644
--- a/net/ipv4/sysctl_net_ipv4.c
+++ b/net/ipv4/sysctl_net_ipv4.c
@@ -45,6 +45,9 @@ static int tcp_syn_retries_max = MAX_TCP_SYNCNT;
static int ip_ping_group_range_min[] = { 0, 0 };
static int ip_ping_group_range_max[] = { GID_T_MAX, GID_T_MAX };
+/* obsolete */
+static int sysctl_tcp_low_latency __read_mostly;
+
/* Update system visible IP port range */
static void set_local_port_range(struct net *net, int range[2])
{
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index 71ce33decd97..e022874d509f 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -400,7 +400,6 @@ void tcp_init_sock(struct sock *sk)
tp->out_of_order_queue = RB_ROOT;
tcp_init_xmit_timers(sk);
- tcp_prequeue_init(tp);
INIT_LIST_HEAD(&tp->tsq_node);
icsk->icsk_rto = TCP_TIMEOUT_INIT;
@@ -1525,20 +1524,6 @@ static void tcp_cleanup_rbuf(struct sock *sk, int copied)
tcp_send_ack(sk);
}
-static void tcp_prequeue_process(struct sock *sk)
-{
- struct sk_buff *skb;
- struct tcp_sock *tp = tcp_sk(sk);
-
- NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPPREQUEUED);
-
- while ((skb = __skb_dequeue(&tp->ucopy.prequeue)) != NULL)
- sk_backlog_rcv(sk, skb);
-
- /* Clear memory counter. */
- tp->ucopy.memory = 0;
-}
-
static struct sk_buff *tcp_recv_skb(struct sock *sk, u32 seq, u32 *off)
{
struct sk_buff *skb;
@@ -1671,7 +1656,6 @@ int tcp_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, int nonblock,
int err;
int target; /* Read at least this many bytes */
long timeo;
- struct task_struct *user_recv = NULL;
struct sk_buff *skb, *last;
u32 urg_hole = 0;
@@ -1806,51 +1790,6 @@ int tcp_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, int nonblock,
tcp_cleanup_rbuf(sk, copied);
- if (!sysctl_tcp_low_latency && tp->ucopy.task == user_recv) {
- /* Install new reader */
- if (!user_recv && !(flags & (MSG_TRUNC | MSG_PEEK))) {
- user_recv = current;
- tp->ucopy.task = user_recv;
- tp->ucopy.msg = msg;
- }
-
- tp->ucopy.len = len;
-
- WARN_ON(tp->copied_seq != tp->rcv_nxt &&
- !(flags & (MSG_PEEK | MSG_TRUNC)));
-
- /* Ugly... If prequeue is not empty, we have to
- * process it before releasing socket, otherwise
- * order will be broken at second iteration.
- * More elegant solution is required!!!
- *
- * Look: we have the following (pseudo)queues:
- *
- * 1. packets in flight
- * 2. backlog
- * 3. prequeue
- * 4. receive_queue
- *
- * Each queue can be processed only if the next ones
- * are empty. At this point we have empty receive_queue.
- * But prequeue _can_ be not empty after 2nd iteration,
- * when we jumped to start of loop because backlog
- * processing added something to receive_queue.
- * We cannot release_sock(), because backlog contains
- * packets arrived _after_ prequeued ones.
- *
- * Shortly, algorithm is clear --- to process all
- * the queues in order. We could make it more directly,
- * requeueing packets from backlog to prequeue, if
- * is not empty. It is more elegant, but eats cycles,
- * unfortunately.
- */
- if (!skb_queue_empty(&tp->ucopy.prequeue))
- goto do_prequeue;
-
- /* __ Set realtime policy in scheduler __ */
- }
-
if (copied >= target) {
/* Do not sleep, just process backlog. */
release_sock(sk);
@@ -1859,31 +1798,6 @@ int tcp_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, int nonblock,
sk_wait_data(sk, &timeo, last);
}
- if (user_recv) {
- int chunk;
-
- /* __ Restore normal policy in scheduler __ */
-
- chunk = len - tp->ucopy.len;
- if (chunk != 0) {
- NET_ADD_STATS(sock_net(sk), LINUX_MIB_TCPDIRECTCOPYFROMBACKLOG, chunk);
- len -= chunk;
- copied += chunk;
- }
-
- if (tp->rcv_nxt == tp->copied_seq &&
- !skb_queue_empty(&tp->ucopy.prequeue)) {
-do_prequeue:
- tcp_prequeue_process(sk);
-
- chunk = len - tp->ucopy.len;
- if (chunk != 0) {
- NET_ADD_STATS(sock_net(sk), LINUX_MIB_TCPDIRECTCOPYFROMPREQUEUE, chunk);
- len -= chunk;
- copied += chunk;
- }
- }
- }
if ((flags & MSG_PEEK) &&
(peek_seq - copied - urg_hole != tp->copied_seq)) {
net_dbg_ratelimited("TCP(%s:%d): Application bug, race in MSG_PEEK\n",
@@ -1934,10 +1848,8 @@ do_prequeue:
tcp_rcv_space_adjust(sk);
skip_copy:
- if (tp->urg_data && after(tp->copied_seq, tp->urg_seq)) {
+ if (tp->urg_data && after(tp->copied_seq, tp->urg_seq))
tp->urg_data = 0;
- tcp_fast_path_check(sk);
- }
if (used + offset < skb->len)
continue;
@@ -1955,25 +1867,6 @@ skip_copy:
break;
} while (len > 0);
- if (user_recv) {
- if (!skb_queue_empty(&tp->ucopy.prequeue)) {
- int chunk;
-
- tp->ucopy.len = copied > 0 ? len : 0;
-
- tcp_prequeue_process(sk);
-
- if (copied > 0 && (chunk = len - tp->ucopy.len) != 0) {
- NET_ADD_STATS(sock_net(sk), LINUX_MIB_TCPDIRECTCOPYFROMPREQUEUE, chunk);
- len -= chunk;
- copied += chunk;
- }
- }
-
- tp->ucopy.task = NULL;
- tp->ucopy.len = 0;
- }
-
/* According to UNIX98, msg_name/msg_namelen are ignored
* on connected socket. I was just happy when found this 8) --ANK
*/
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index adc3f3e9468c..af0a98d54b62 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -103,7 +103,6 @@ int sysctl_tcp_invalid_ratelimit __read_mostly = HZ/2;
#define FLAG_DATA_SACKED 0x20 /* New SACK. */
#define FLAG_ECE 0x40 /* ECE in this ACK */
#define FLAG_LOST_RETRANS 0x80 /* This ACK marks some retransmission lost */
-#define FLAG_SLOWPATH 0x100 /* Do not skip RFC checks for window update.*/
#define FLAG_ORIG_SACK_ACKED 0x200 /* Never retransmitted data are (s)acked */
#define FLAG_SND_UNA_ADVANCED 0x400 /* Snd_una was changed (!= FLAG_DATA_ACKED) */
#define FLAG_DSACKING_ACK 0x800 /* SACK blocks contained D-SACK info */
@@ -3367,12 +3366,6 @@ static int tcp_ack_update_window(struct sock *sk, const struct sk_buff *skb, u32
if (tp->snd_wnd != nwin) {
tp->snd_wnd = nwin;
- /* Note, it is the only place, where
- * fast path is recovered for sending TCP.
- */
- tp->pred_flags = 0;
- tcp_fast_path_check(sk);
-
if (tcp_send_head(sk))
tcp_slow_start_after_idle_check(sk);
@@ -3554,6 +3547,7 @@ static int tcp_ack(struct sock *sk, const struct sk_buff *skb, int flag)
u32 lost = tp->lost;
int acked = 0; /* Number of packets newly acked */
int rexmit = REXMIT_NONE; /* Flag to (re)transmit to recover losses */
+ u32 ack_ev_flags = 0;
sack_state.first_sackt = 0;
sack_state.rate = &rs;
@@ -3597,42 +3591,26 @@ static int tcp_ack(struct sock *sk, const struct sk_buff *skb, int flag)
if (flag & FLAG_UPDATE_TS_RECENT)
tcp_replace_ts_recent(tp, TCP_SKB_CB(skb)->seq);
- if (!(flag & FLAG_SLOWPATH) && after(ack, prior_snd_una)) {
- /* Window is constant, pure forward advance.
- * No more checks are required.
- * Note, we use the fact that SND.UNA>=SND.WL2.
- */
- tcp_update_wl(tp, ack_seq);
- tcp_snd_una_update(tp, ack);
- flag |= FLAG_WIN_UPDATE;
-
- tcp_in_ack_event(sk, CA_ACK_WIN_UPDATE);
-
- NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPHPACKS);
- } else {
- u32 ack_ev_flags = CA_ACK_SLOWPATH;
-
- if (ack_seq != TCP_SKB_CB(skb)->end_seq)
- flag |= FLAG_DATA;
- else
- NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPPUREACKS);
+ if (ack_seq != TCP_SKB_CB(skb)->end_seq)
+ flag |= FLAG_DATA;
+ else
+ NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPPUREACKS);
- flag |= tcp_ack_update_window(sk, skb, ack, ack_seq);
+ flag |= tcp_ack_update_window(sk, skb, ack, ack_seq);
- if (TCP_SKB_CB(skb)->sacked)
- flag |= tcp_sacktag_write_queue(sk, skb, prior_snd_una,
- &sack_state);
+ if (TCP_SKB_CB(skb)->sacked)
+ flag |= tcp_sacktag_write_queue(sk, skb, prior_snd_una,
+ &sack_state);
- if (tcp_ecn_rcv_ecn_echo(tp, tcp_hdr(skb))) {
- flag |= FLAG_ECE;
- ack_ev_flags |= CA_ACK_ECE;
- }
+ if (tcp_ecn_rcv_ecn_echo(tp, tcp_hdr(skb))) {
+ flag |= FLAG_ECE;
+ ack_ev_flags = CA_ACK_ECE;
+ }
- if (flag & FLAG_WIN_UPDATE)
- ack_ev_flags |= CA_ACK_WIN_UPDATE;
+ if (flag & FLAG_WIN_UPDATE)
+ ack_ev_flags |= CA_ACK_WIN_UPDATE;
- tcp_in_ack_event(sk, ack_ev_flags);
- }
+ tcp_in_ack_event(sk, ack_ev_flags);
/* We passed data and got it acked, remove any soft error
* log. Something worked...
@@ -4398,8 +4376,6 @@ static void tcp_data_queue_ofo(struct sock *sk, struct sk_buff *skb)
return;
}
- /* Disable header prediction. */
- tp->pred_flags = 0;
inet_csk_schedule_ack(sk);
NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPOFOQUEUE);
@@ -4611,32 +4587,14 @@ static void tcp_data_queue(struct sock *sk, struct sk_buff *skb)
goto out_of_window;
/* Ok. In sequence. In window. */
- if (tp->ucopy.task == current &&
- tp->copied_seq == tp->rcv_nxt && tp->ucopy.len &&
- sock_owned_by_user(sk) && !tp->urg_data) {
- int chunk = min_t(unsigned int, skb->len,
- tp->ucopy.len);
-
- __set_current_state(TASK_RUNNING);
-
- if (!skb_copy_datagram_msg(skb, 0, tp->ucopy.msg, chunk)) {
- tp->ucopy.len -= chunk;
- tp->copied_seq += chunk;
- eaten = (chunk == skb->len);
- tcp_rcv_space_adjust(sk);
- }
- }
-
- if (eaten <= 0) {
queue_and_out:
- if (eaten < 0) {
- if (skb_queue_len(&sk->sk_receive_queue) == 0)
- sk_forced_mem_schedule(sk, skb->truesize);
- else if (tcp_try_rmem_schedule(sk, skb, skb->truesize))
- goto drop;
- }
- eaten = tcp_queue_rcv(sk, skb, 0, &fragstolen);
+ if (eaten < 0) {
+ if (skb_queue_len(&sk->sk_receive_queue) == 0)
+ sk_forced_mem_schedule(sk, skb->truesize);
+ else if (tcp_try_rmem_schedule(sk, skb, skb->truesize))
+ goto drop;
}
+ eaten = tcp_queue_rcv(sk, skb, 0, &fragstolen);
tcp_rcv_nxt_update(tp, TCP_SKB_CB(skb)->end_seq);
if (skb->len)
tcp_event_data_recv(sk, skb);
@@ -4656,8 +4614,6 @@ queue_and_out:
if (tp->rx_opt.num_sacks)
tcp_sack_remove(tp);
- tcp_fast_path_check(sk);
-
if (eaten > 0)
kfree_skb_partial(skb, fragstolen);
if (!sock_flag(sk, SOCK_DEAD))
@@ -4983,7 +4939,6 @@ static int tcp_prune_queue(struct sock *sk)
NET_INC_STATS(sock_net(sk), LINUX_MIB_RCVPRUNED);
/* Massive buffer overcommit. */
- tp->pred_flags = 0;
return -1;
}
@@ -5155,9 +5110,6 @@ static void tcp_check_urg(struct sock *sk, const struct tcphdr *th)
tp->urg_data = TCP_URG_NOTYET;
tp->urg_seq = ptr;
-
- /* Disable header prediction. */
- tp->pred_flags = 0;
}
/* This is the 'fast' part of urgent handling. */
@@ -5186,26 +5138,6 @@ static void tcp_urg(struct sock *sk, struct sk_buff *skb, const struct tcphdr *t
}
}
-static int tcp_copy_to_iovec(struct sock *sk, struct sk_buff *skb, int hlen)
-{
- struct tcp_sock *tp = tcp_sk(sk);
- int chunk = skb->len - hlen;
- int err;
-
- if (skb_csum_unnecessary(skb))
- err = skb_copy_datagram_msg(skb, hlen, tp->ucopy.msg, chunk);
- else
- err = skb_copy_and_csum_datagram_msg(skb, hlen, tp->ucopy.msg);
-
- if (!err) {
- tp->ucopy.len -= chunk;
- tp->copied_seq += chunk;
- tcp_rcv_space_adjust(sk);
- }
-
- return err;
-}
-
/* Accept RST for rcv_nxt - 1 after a FIN.
* When tcp connections are abruptly terminated from Mac OSX (via ^C), a
* FIN is sent followed by a RST packet. The RST is sent with the same
@@ -5336,26 +5268,6 @@ discard:
/*
* TCP receive function for the ESTABLISHED state.
- *
- * It is split into a fast path and a slow path. The fast path is
- * disabled when:
- * - A zero window was announced from us - zero window probing
- * is only handled properly in the slow path.
- * - Out of order segments arrived.
- * - Urgent data is expected.
- * - There is no buffer space left
- * - Unexpected TCP flags/window values/header lengths are received
- * (detected by checking the TCP header against pred_flags)
- * - Data is sent in both directions. Fast path only supports pure senders
- * or pure receivers (this means either the sequence number or the ack
- * value must stay constant)
- * - Unexpected TCP option.
- *
- * When these conditions are not satisfied it drops into a standard
- * receive procedure patterned after RFC793 to handle all cases.
- * The first three cases are guaranteed by proper pred_flags setting,
- * the rest is checked inline. Fast processing is turned on in
- * tcp_data_queue when everything is OK.
*/
void tcp_rcv_established(struct sock *sk, struct sk_buff *skb,
const struct tcphdr *th)
@@ -5366,172 +5278,19 @@ void tcp_rcv_established(struct sock *sk, struct sk_buff *skb,
tcp_mstamp_refresh(tp);
if (unlikely(!sk->sk_rx_dst))
inet_csk(sk)->icsk_af_ops->sk_rx_dst_set(sk, skb);
- /*
- * Header prediction.
- * The code loosely follows the one in the famous
- * "30 instruction TCP receive" Van Jacobson mail.
- *
- * Van's trick is to deposit buffers into socket queue
- * on a device interrupt, to call tcp_recv function
- * on the receive process context and checksum and copy
- * the buffer to user space. smart...
- *
- * Our current scheme is not silly either but we take the
- * extra cost of the net_bh soft interrupt processing...
- * We do checksum and copy also but from device to kernel.
- */
tp->rx_opt.saw_tstamp = 0;
- /* pred_flags is 0xS?10 << 16 + snd_wnd
- * 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
- * space for instance)
- * PSH flag is ignored.
- */
-
- if ((tcp_flag_word(th) & TCP_HP_BITS) == tp->pred_flags &&
- TCP_SKB_CB(skb)->seq == tp->rcv_nxt &&
- !after(TCP_SKB_CB(skb)->ack_seq, tp->snd_nxt)) {
- int tcp_header_len = tp->tcp_header_len;
-
- /* Timestamp header prediction: tcp_header_len
- * is automatically equal to th->doff*4 due to pred_flags
- * match.
- */
-
- /* Check timestamp */
- if (tcp_header_len == sizeof(struct tcphdr) + TCPOLEN_TSTAMP_ALIGNED) {
- /* No? Slow path! */
- if (!tcp_parse_aligned_timestamp(tp, th))
- goto slow_path;
-
- /* If PAWS failed, check it more carefully in slow path */
- if ((s32)(tp->rx_opt.rcv_tsval - tp->rx_opt.ts_recent) < 0)
- goto slow_path;
-
- /* DO NOT update ts_recent here, if checksum fails
- * and timestamp was corrupted part, it will result
- * in a hung connection since we will drop all
- * future packets due to the PAWS test.
- */
- }
-
- if (len <= tcp_header_len) {
- /* Bulk data transfer: sender */
- if (len == tcp_header_len) {
- /* Predicted packet is in window by definition.
- * seq == rcv_nxt and rcv_wup <= rcv_nxt.
- * Hence, check seq<=rcv_wup reduces to:
- */
- if (tcp_header_len ==
- (sizeof(struct tcphdr) + TCPOLEN_TSTAMP_ALIGNED) &&
- tp->rcv_nxt == tp->rcv_wup)
- tcp_store_ts_recent(tp);
-
- /* We know that such packets are checksummed
- * on entry.
- */
- tcp_ack(sk, skb, 0);
- __kfree_skb(skb);
- tcp_data_snd_check(sk);
- return;
- } else { /* Header too small */
- TCP_INC_STATS(sock_net(sk), TCP_MIB_INERRS);
- goto discard;
- }
- } else {
- int eaten = 0;
- bool fragstolen = false;
-
- if (tp->ucopy.task == current &&
- tp->copied_seq == tp->rcv_nxt &&
- len - tcp_header_len <= tp->ucopy.len &&
- sock_owned_by_user(sk)) {
- __set_current_state(TASK_RUNNING);
-
- if (!tcp_copy_to_iovec(sk, skb, tcp_header_len)) {
- /* Predicted packet is in window by definition.
- * seq == rcv_nxt and rcv_wup <= rcv_nxt.
- * Hence, check seq<=rcv_wup reduces to:
- */
- if (tcp_header_len ==
- (sizeof(struct tcphdr) +
- TCPOLEN_TSTAMP_ALIGNED) &&
- tp->rcv_nxt == tp->rcv_wup)
- tcp_store_ts_recent(tp);
-
- tcp_rcv_rtt_measure_ts(sk, skb);
-
- __skb_pull(skb, tcp_header_len);
- tcp_rcv_nxt_update(tp, TCP_SKB_CB(skb)->end_seq);
- NET_INC_STATS(sock_net(sk),
- LINUX_MIB_TCPHPHITSTOUSER);
- eaten = 1;
- }
- }
- if (!eaten) {
- if (tcp_checksum_complete(skb))
- goto csum_error;
-
- if ((int)skb->truesize > sk->sk_forward_alloc)
- goto step5;
-
- /* Predicted packet is in window by definition.
- * seq == rcv_nxt and rcv_wup <= rcv_nxt.
- * Hence, check seq<=rcv_wup reduces to:
- */
- if (tcp_header_len ==
- (sizeof(struct tcphdr) + TCPOLEN_TSTAMP_ALIGNED) &&
- tp->rcv_nxt == tp->rcv_wup)
- tcp_store_ts_recent(tp);
-
- tcp_rcv_rtt_measure_ts(sk, skb);
-
- NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPHPHITS);
-
- /* Bulk data transfer: receiver */
- eaten = tcp_queue_rcv(sk, skb, tcp_header_len,
- &fragstolen);
- }
-
- tcp_event_data_recv(sk, skb);
-
- if (TCP_SKB_CB(skb)->ack_seq != tp->snd_una) {
- /* Well, only one small jumplet in fast path... */
- tcp_ack(sk, skb, FLAG_DATA);
- tcp_data_snd_check(sk);
- if (!inet_csk_ack_scheduled(sk))
- goto no_ack;
- }
-
- __tcp_ack_snd_check(sk, 0);
-no_ack:
- if (eaten)
- kfree_skb_partial(skb, fragstolen);
- sk->sk_data_ready(sk);
- return;
- }
- }
-
-slow_path:
if (len < (th->doff << 2) || tcp_checksum_complete(skb))
goto csum_error;
if (!th->ack && !th->rst && !th->syn)
goto discard;
- /*
- * Standard slow path.
- */
-
if (!tcp_validate_incoming(sk, skb, th, 1))
return;
-step5:
- if (tcp_ack(sk, skb, FLAG_SLOWPATH | FLAG_UPDATE_TS_RECENT) < 0)
+ if (tcp_ack(sk, skb, FLAG_UPDATE_TS_RECENT) < 0)
goto discard;
tcp_rcv_rtt_measure_ts(sk, skb);
@@ -5585,11 +5344,10 @@ void tcp_finish_connect(struct sock *sk, struct sk_buff *skb)
if (sock_flag(sk, SOCK_KEEPOPEN))
inet_csk_reset_keepalive_timer(sk, keepalive_time_when(tp));
- if (!tp->rx_opt.snd_wscale)
- __tcp_fast_path_on(tp, tp->snd_wnd);
- else
- tp->pred_flags = 0;
-
+ if (!sock_flag(sk, SOCK_DEAD)) {
+ sk->sk_state_change(sk);
+ sk_wake_async(sk, SOCK_WAKE_IO, POLL_OUT);
+ }
}
static bool tcp_rcv_fastopen_synack(struct sock *sk, struct sk_buff *synack,
@@ -5718,7 +5476,7 @@ static int tcp_rcv_synsent_state_process(struct sock *sk, struct sk_buff *skb,
tcp_ecn_rcv_synack(tp, th);
tcp_init_wl(tp, TCP_SKB_CB(skb)->seq);
- tcp_ack(sk, skb, FLAG_SLOWPATH);
+ tcp_ack(sk, skb, 0);
/* Ok.. it's good. Set up sequence numbers and
* move to established.
@@ -5954,8 +5712,8 @@ int tcp_rcv_state_process(struct sock *sk, struct sk_buff *skb)
return 0;
/* step 5: check the ACK field */
- acceptable = tcp_ack(sk, skb, FLAG_SLOWPATH |
- FLAG_UPDATE_TS_RECENT |
+
+ acceptable = tcp_ack(sk, skb, FLAG_UPDATE_TS_RECENT |
FLAG_NO_CHALLENGE_ACK) > 0;
if (!acceptable) {
@@ -6023,7 +5781,6 @@ int tcp_rcv_state_process(struct sock *sk, struct sk_buff *skb)
tp->lsndtime = tcp_jiffies32;
tcp_initialize_rcv_mss(sk);
- tcp_fast_path_on(tp);
break;
case TCP_FIN_WAIT1: {
diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index 3a19ea28339f..9b51663cd5a4 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -85,8 +85,6 @@
#include <crypto/hash.h>
#include <linux/scatterlist.h>
-int sysctl_tcp_low_latency __read_mostly;
-
#ifdef CONFIG_TCP_MD5SIG
static int tcp_v4_md5_hash_hdr(char *md5_hash, const struct tcp_md5sig_key *key,
__be32 daddr, __be32 saddr, const struct tcphdr *th);
@@ -1541,61 +1539,6 @@ void tcp_v4_early_demux(struct sk_buff *skb)
}
}
-/* Packet is added to VJ-style prequeue for processing in process
- * context, if a reader task is waiting. Apparently, this exciting
- * idea (VJ's mail "Re: query about TCP header on tcp-ip" of 07 Sep 93)
- * failed somewhere. Latency? Burstiness? Well, at least now we will
- * see, why it failed. 8)8) --ANK
- *
- */
-bool tcp_prequeue(struct sock *sk, struct sk_buff *skb)
-{
- struct tcp_sock *tp = tcp_sk(sk);
-
- if (sysctl_tcp_low_latency || !tp->ucopy.task)
- return false;
-
- if (skb->len <= tcp_hdrlen(skb) &&
- skb_queue_len(&tp->ucopy.prequeue) == 0)
- return false;
-
- /* Before escaping RCU protected region, we need to take care of skb
- * dst. Prequeue is only enabled for established sockets.
- * For such sockets, we might need the skb dst only to set sk->sk_rx_dst
- * Instead of doing full sk_rx_dst validity here, let's perform
- * an optimistic check.
- */
- if (likely(sk->sk_rx_dst))
- skb_dst_drop(skb);
- else
- skb_dst_force_safe(skb);
-
- __skb_queue_tail(&tp->ucopy.prequeue, skb);
- tp->ucopy.memory += skb->truesize;
- if (skb_queue_len(&tp->ucopy.prequeue) >= 32 ||
- tp->ucopy.memory + atomic_read(&sk->sk_rmem_alloc) > sk->sk_rcvbuf) {
- struct sk_buff *skb1;
-
- BUG_ON(sock_owned_by_user(sk));
- __NET_ADD_STATS(sock_net(sk), LINUX_MIB_TCPPREQUEUEDROPPED,
- skb_queue_len(&tp->ucopy.prequeue));
-
- while ((skb1 = __skb_dequeue(&tp->ucopy.prequeue)) != NULL)
- sk_backlog_rcv(sk, skb1);
-
- tp->ucopy.memory = 0;
- } else if (skb_queue_len(&tp->ucopy.prequeue) == 1) {
- wake_up_interruptible_sync_poll(sk_sleep(sk),
- POLLIN | POLLRDNORM | POLLRDBAND);
- if (!inet_csk_ack_scheduled(sk))
- inet_csk_reset_xmit_timer(sk, ICSK_TIME_DACK,
- (3 * tcp_rto_min(sk)) / 4,
- TCP_RTO_MAX);
- }
- return true;
-}
-EXPORT_SYMBOL(tcp_prequeue);
-
bool tcp_add_backlog(struct sock *sk, struct sk_buff *skb)
{
u32 limit = sk->sk_rcvbuf + sk->sk_sndbuf;
@@ -1770,8 +1713,7 @@ process:
tcp_segs_in(tcp_sk(sk), skb);
ret = 0;
if (!sock_owned_by_user(sk)) {
- if (!tcp_prequeue(sk, skb))
- ret = tcp_v4_do_rcv(sk, skb);
+ ret = tcp_v4_do_rcv(sk, skb);
} else if (tcp_add_backlog(sk, skb)) {
goto discard_and_relse;
}
@@ -1936,9 +1878,6 @@ void tcp_v4_destroy_sock(struct sock *sk)
}
#endif
- /* Clean prequeue, it must be empty really */
- __skb_queue_purge(&tp->ucopy.prequeue);
-
/* Clean up a referenced TCP bind bucket. */
if (inet_csk(sk)->icsk_bind_hash)
inet_put_port(sk);
diff --git a/net/ipv4/tcp_minisocks.c b/net/ipv4/tcp_minisocks.c
index 0ff83c1637d8..1537b87c657f 100644
--- a/net/ipv4/tcp_minisocks.c
+++ b/net/ipv4/tcp_minisocks.c
@@ -436,8 +436,6 @@ struct sock *tcp_create_openreq_child(const struct sock *sk,
struct tcp_sock *newtp = tcp_sk(newsk);
/* Now setup tcp_sock */
- newtp->pred_flags = 0;
-
newtp->rcv_wup = newtp->copied_seq =
newtp->rcv_nxt = treq->rcv_isn + 1;
newtp->segs_in = 1;
@@ -445,7 +443,6 @@ struct sock *tcp_create_openreq_child(const struct sock *sk,
newtp->snd_sml = newtp->snd_una =
newtp->snd_nxt = newtp->snd_up = treq->snt_isn + 1;
- tcp_prequeue_init(newtp);
INIT_LIST_HEAD(&newtp->tsq_node);
tcp_init_wl(newtp, treq->rcv_isn);
diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index 886d874775df..8380464aead1 100644
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -295,9 +295,7 @@ static u16 tcp_select_window(struct sock *sk)
/* RFC1323 scaling applied */
new_win >>= tp->rx_opt.rcv_wscale;
- /* If we advertise zero window, disable fast path. */
if (new_win == 0) {
- tp->pred_flags = 0;
if (old_win)
NET_INC_STATS(sock_net(sk),
LINUX_MIB_TCPTOZEROWINDOWADV);
diff --git a/net/ipv4/tcp_timer.c b/net/ipv4/tcp_timer.c
index c0feeeef962a..f753f9d2fee3 100644
--- a/net/ipv4/tcp_timer.c
+++ b/net/ipv4/tcp_timer.c
@@ -239,7 +239,6 @@ static int tcp_write_timeout(struct sock *sk)
/* Called with BH disabled */
void tcp_delack_timer_handler(struct sock *sk)
{
- struct tcp_sock *tp = tcp_sk(sk);
struct inet_connection_sock *icsk = inet_csk(sk);
sk_mem_reclaim_partial(sk);
@@ -254,17 +253,6 @@ void tcp_delack_timer_handler(struct sock *sk)
}
icsk->icsk_ack.pending &= ~ICSK_ACK_TIMER;
- if (!skb_queue_empty(&tp->ucopy.prequeue)) {
- struct sk_buff *skb;
-
- __NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPSCHEDULERFAILED);
-
- while ((skb = __skb_dequeue(&tp->ucopy.prequeue)) != NULL)
- sk_backlog_rcv(sk, skb);
-
- tp->ucopy.memory = 0;
- }
-
if (inet_csk_ack_scheduled(sk)) {
if (!icsk->icsk_ack.pingpong) {
/* Delayed ACK missed: inflate ATO. */
diff --git a/net/ipv4/tcp_westwood.c b/net/ipv4/tcp_westwood.c
index bec9cafbe3f9..e5de84310949 100644
--- a/net/ipv4/tcp_westwood.c
+++ b/net/ipv4/tcp_westwood.c
@@ -154,24 +154,6 @@ static inline void update_rtt_min(struct westwood *w)
}
/*
- * @westwood_fast_bw
- * It is called when we are in fast path. In particular it is called when
- * header prediction is successful. In such case in fact update is
- * straight forward and doesn't need any particular care.
- */
-static inline void westwood_fast_bw(struct sock *sk)
-{
- const struct tcp_sock *tp = tcp_sk(sk);
- struct westwood *w = inet_csk_ca(sk);
-
- westwood_update_window(sk);
-
- w->bk += tp->snd_una - w->snd_una;
- w->snd_una = tp->snd_una;
- update_rtt_min(w);
-}
-
-/*
* @westwood_acked_count
* This function evaluates cumul_ack for evaluating bk in case of
* delayed or partial acks.
@@ -223,17 +205,12 @@ static u32 tcp_westwood_bw_rttmin(const struct sock *sk)
static void tcp_westwood_ack(struct sock *sk, u32 ack_flags)
{
- if (ack_flags & CA_ACK_SLOWPATH) {
- struct westwood *w = inet_csk_ca(sk);
-
- westwood_update_window(sk);
- w->bk += westwood_acked_count(sk);
+ struct westwood *w = inet_csk_ca(sk);
- update_rtt_min(w);
- return;
- }
+ westwood_update_window(sk);
+ w->bk += westwood_acked_count(sk);
- westwood_fast_bw(sk);
+ update_rtt_min(w);
}
static void tcp_westwood_event(struct sock *sk, enum tcp_ca_event event)
diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c
index 2968a33cca7d..39ee8e7fc4bd 100644
--- a/net/ipv6/tcp_ipv6.c
+++ b/net/ipv6/tcp_ipv6.c
@@ -1505,8 +1505,7 @@ process:
tcp_segs_in(tcp_sk(sk), skb);
ret = 0;
if (!sock_owned_by_user(sk)) {
- if (!tcp_prequeue(sk, skb))
- ret = tcp_v6_do_rcv(sk, skb);
+ ret = tcp_v6_do_rcv(sk, skb);
} else if (tcp_add_backlog(sk, skb)) {
goto discard_and_relse;
}