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-rw-r--r--Documentation/networking/ip-sysctl.txt13
-rw-r--r--include/linux/tcp.h2
-rw-r--r--include/net/netns/ipv4.h2
-rw-r--r--include/net/tcp.h5
-rw-r--r--include/uapi/linux/snmp.h1
-rw-r--r--net/ipv4/proc.c1
-rw-r--r--net/ipv4/sysctl_net_ipv4.c17
-rw-r--r--net/ipv4/tcp.c1
-rw-r--r--net/ipv4/tcp_input.c38
-rw-r--r--net/ipv4/tcp_ipv4.c2
-rw-r--r--net/ipv4/tcp_output.c9
-rw-r--r--net/ipv4/tcp_timer.c25
12 files changed, 107 insertions, 9 deletions
diff --git a/Documentation/networking/ip-sysctl.txt b/Documentation/networking/ip-sysctl.txt
index ea304a23c8d7..924bd51327b7 100644
--- a/Documentation/networking/ip-sysctl.txt
+++ b/Documentation/networking/ip-sysctl.txt
@@ -525,6 +525,19 @@ tcp_rmem - vector of 3 INTEGERs: min, default, max
tcp_sack - BOOLEAN
Enable select acknowledgments (SACKS).
+tcp_comp_sack_delay_ns - LONG INTEGER
+ TCP tries to reduce number of SACK sent, using a timer
+ based on 5% of SRTT, capped by this sysctl, in nano seconds.
+ The default is 1ms, based on TSO autosizing period.
+
+ Default : 1,000,000 ns (1 ms)
+
+tcp_comp_sack_nr - INTEGER
+ Max numer of SACK that can be compressed.
+ Using 0 disables SACK compression.
+
+ Detault : 44
+
tcp_slow_start_after_idle - BOOLEAN
If set, provide RFC2861 behavior and time out the congestion
window after an idle period. An idle period is defined at
diff --git a/include/linux/tcp.h b/include/linux/tcp.h
index 807776928cb8..72705eaf4b84 100644
--- a/include/linux/tcp.h
+++ b/include/linux/tcp.h
@@ -218,6 +218,7 @@ struct tcp_sock {
reord:1; /* reordering detected */
} rack;
u16 advmss; /* Advertised MSS */
+ u8 compressed_ack;
u32 chrono_start; /* Start time in jiffies of a TCP chrono */
u32 chrono_stat[3]; /* Time in jiffies for chrono_stat stats */
u8 chrono_type:2, /* current chronograph type */
@@ -297,6 +298,7 @@ struct tcp_sock {
u32 sacked_out; /* SACK'd packets */
struct hrtimer pacing_timer;
+ struct hrtimer compressed_ack_timer;
/* from STCP, retrans queue hinting */
struct sk_buff* lost_skb_hint;
diff --git a/include/net/netns/ipv4.h b/include/net/netns/ipv4.h
index 8491bc9c86b1..661348f23ea5 100644
--- a/include/net/netns/ipv4.h
+++ b/include/net/netns/ipv4.h
@@ -160,6 +160,8 @@ struct netns_ipv4 {
int sysctl_tcp_pacing_ca_ratio;
int sysctl_tcp_wmem[3];
int sysctl_tcp_rmem[3];
+ int sysctl_tcp_comp_sack_nr;
+ unsigned long sysctl_tcp_comp_sack_delay_ns;
struct inet_timewait_death_row tcp_death_row;
int sysctl_max_syn_backlog;
int sysctl_tcp_fastopen;
diff --git a/include/net/tcp.h b/include/net/tcp.h
index 6deb540297cc..952d842a604a 100644
--- a/include/net/tcp.h
+++ b/include/net/tcp.h
@@ -559,7 +559,10 @@ void tcp_init_xmit_timers(struct sock *);
static inline void tcp_clear_xmit_timers(struct sock *sk)
{
if (hrtimer_try_to_cancel(&tcp_sk(sk)->pacing_timer) == 1)
- sock_put(sk);
+ __sock_put(sk);
+
+ if (hrtimer_try_to_cancel(&tcp_sk(sk)->compressed_ack_timer) == 1)
+ __sock_put(sk);
inet_csk_clear_xmit_timers(sk);
}
diff --git a/include/uapi/linux/snmp.h b/include/uapi/linux/snmp.h
index d02e859301ff..750d89120335 100644
--- a/include/uapi/linux/snmp.h
+++ b/include/uapi/linux/snmp.h
@@ -278,6 +278,7 @@ enum
LINUX_MIB_TCPMTUPSUCCESS, /* TCPMTUPSuccess */
LINUX_MIB_TCPDELIVERED, /* TCPDelivered */
LINUX_MIB_TCPDELIVEREDCE, /* TCPDeliveredCE */
+ LINUX_MIB_TCPACKCOMPRESSED, /* TCPAckCompressed */
__LINUX_MIB_MAX
};
diff --git a/net/ipv4/proc.c b/net/ipv4/proc.c
index 261b71d0ccc5..6c1ff89a60fa 100644
--- a/net/ipv4/proc.c
+++ b/net/ipv4/proc.c
@@ -298,6 +298,7 @@ static const struct snmp_mib snmp4_net_list[] = {
SNMP_MIB_ITEM("TCPMTUPSuccess", LINUX_MIB_TCPMTUPSUCCESS),
SNMP_MIB_ITEM("TCPDelivered", LINUX_MIB_TCPDELIVERED),
SNMP_MIB_ITEM("TCPDeliveredCE", LINUX_MIB_TCPDELIVEREDCE),
+ SNMP_MIB_ITEM("TCPAckCompressed", LINUX_MIB_TCPACKCOMPRESSED),
SNMP_MIB_SENTINEL
};
diff --git a/net/ipv4/sysctl_net_ipv4.c b/net/ipv4/sysctl_net_ipv4.c
index 4b195bac8ac0..d2eed3ddcb0a 100644
--- a/net/ipv4/sysctl_net_ipv4.c
+++ b/net/ipv4/sysctl_net_ipv4.c
@@ -46,6 +46,7 @@ static int tcp_syn_retries_min = 1;
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 };
+static int comp_sack_nr_max = 255;
/* obsolete */
static int sysctl_tcp_low_latency __read_mostly;
@@ -1152,6 +1153,22 @@ static struct ctl_table ipv4_net_table[] = {
.extra1 = &one,
},
{
+ .procname = "tcp_comp_sack_delay_ns",
+ .data = &init_net.ipv4.sysctl_tcp_comp_sack_delay_ns,
+ .maxlen = sizeof(unsigned long),
+ .mode = 0644,
+ .proc_handler = proc_doulongvec_minmax,
+ },
+ {
+ .procname = "tcp_comp_sack_nr",
+ .data = &init_net.ipv4.sysctl_tcp_comp_sack_nr,
+ .maxlen = sizeof(int),
+ .mode = 0644,
+ .proc_handler = proc_dointvec_minmax,
+ .extra1 = &zero,
+ .extra2 = &comp_sack_nr_max,
+ },
+ {
.procname = "udp_rmem_min",
.data = &init_net.ipv4.sysctl_udp_rmem_min,
.maxlen = sizeof(init_net.ipv4.sysctl_udp_rmem_min),
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index 62b776f90037..0a2ea0bbf867 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -2595,6 +2595,7 @@ int tcp_disconnect(struct sock *sk, int flags)
dst_release(sk->sk_rx_dst);
sk->sk_rx_dst = NULL;
tcp_saved_syn_free(tp);
+ tp->compressed_ack = 0;
/* Clean up fastopen related fields */
tcp_free_fastopen_req(tp);
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index 0bf032839548..aebb29ab2fdf 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -4249,6 +4249,8 @@ static void tcp_sack_new_ofo_skb(struct sock *sk, u32 seq, u32 end_seq)
* If the sack array is full, forget about the last one.
*/
if (this_sack >= TCP_NUM_SACKS) {
+ if (tp->compressed_ack)
+ tcp_send_ack(sk);
this_sack--;
tp->rx_opt.num_sacks--;
sp--;
@@ -4715,8 +4717,6 @@ drop:
if (!before(TCP_SKB_CB(skb)->seq, tp->rcv_nxt + tcp_receive_window(tp)))
goto out_of_window;
- tcp_enter_quickack_mode(sk);
-
if (before(TCP_SKB_CB(skb)->seq, tp->rcv_nxt)) {
/* Partial packet, seq < rcv_next < end_seq */
SOCK_DEBUG(sk, "partial packet: rcv_next %X seq %X - %X\n",
@@ -5083,6 +5083,7 @@ static inline void tcp_data_snd_check(struct sock *sk)
static void __tcp_ack_snd_check(struct sock *sk, int ofo_possible)
{
struct tcp_sock *tp = tcp_sk(sk);
+ unsigned long rtt, delay;
/* More than one full frame received... */
if (((tp->rcv_nxt - tp->rcv_wup) > inet_csk(sk)->icsk_ack.rcv_mss &&
@@ -5094,15 +5095,36 @@ static void __tcp_ack_snd_check(struct sock *sk, int ofo_possible)
(tp->rcv_nxt - tp->copied_seq < sk->sk_rcvlowat ||
__tcp_select_window(sk) >= tp->rcv_wnd)) ||
/* We ACK each frame or... */
- tcp_in_quickack_mode(sk) ||
- /* We have out of order data. */
- (ofo_possible && !RB_EMPTY_ROOT(&tp->out_of_order_queue))) {
- /* Then ack it now */
+ tcp_in_quickack_mode(sk)) {
+send_now:
tcp_send_ack(sk);
- } else {
- /* Else, send delayed ack. */
+ return;
+ }
+
+ if (!ofo_possible || RB_EMPTY_ROOT(&tp->out_of_order_queue)) {
tcp_send_delayed_ack(sk);
+ return;
}
+
+ if (!tcp_is_sack(tp) ||
+ tp->compressed_ack >= sock_net(sk)->ipv4.sysctl_tcp_comp_sack_nr)
+ goto send_now;
+ tp->compressed_ack++;
+
+ if (hrtimer_is_queued(&tp->compressed_ack_timer))
+ return;
+
+ /* compress ack timer : 5 % of rtt, but no more than tcp_comp_sack_delay_ns */
+
+ rtt = tp->rcv_rtt_est.rtt_us;
+ if (tp->srtt_us && tp->srtt_us < rtt)
+ rtt = tp->srtt_us;
+
+ delay = min_t(unsigned long, sock_net(sk)->ipv4.sysctl_tcp_comp_sack_delay_ns,
+ rtt * (NSEC_PER_USEC >> 3)/20);
+ sock_hold(sk);
+ hrtimer_start(&tp->compressed_ack_timer, ns_to_ktime(delay),
+ HRTIMER_MODE_REL_PINNED_SOFT);
}
static inline void tcp_ack_snd_check(struct sock *sk)
diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index caf23de88f8a..adbdb503db0c 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -2572,6 +2572,8 @@ static int __net_init tcp_sk_init(struct net *net)
init_net.ipv4.sysctl_tcp_wmem,
sizeof(init_net.ipv4.sysctl_tcp_wmem));
}
+ net->ipv4.sysctl_tcp_comp_sack_delay_ns = NSEC_PER_MSEC;
+ net->ipv4.sysctl_tcp_comp_sack_nr = 44;
net->ipv4.sysctl_tcp_fastopen = TFO_CLIENT_ENABLE;
spin_lock_init(&net->ipv4.tcp_fastopen_ctx_lock);
net->ipv4.sysctl_tcp_fastopen_blackhole_timeout = 60 * 60;
diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index 0d8f950a9006..437bb7ceba7f 100644
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -162,6 +162,15 @@ static void tcp_event_data_sent(struct tcp_sock *tp,
/* Account for an ACK we sent. */
static inline void tcp_event_ack_sent(struct sock *sk, unsigned int pkts)
{
+ struct tcp_sock *tp = tcp_sk(sk);
+
+ if (unlikely(tp->compressed_ack)) {
+ NET_ADD_STATS(sock_net(sk), LINUX_MIB_TCPACKCOMPRESSED,
+ tp->compressed_ack);
+ tp->compressed_ack = 0;
+ if (hrtimer_try_to_cancel(&tp->compressed_ack_timer) == 1)
+ __sock_put(sk);
+ }
tcp_dec_quickack_mode(sk, pkts);
inet_csk_clear_xmit_timer(sk, ICSK_TIME_DACK);
}
diff --git a/net/ipv4/tcp_timer.c b/net/ipv4/tcp_timer.c
index 92bdf64fffae..3b3611729928 100644
--- a/net/ipv4/tcp_timer.c
+++ b/net/ipv4/tcp_timer.c
@@ -708,6 +708,27 @@ out:
sock_put(sk);
}
+static enum hrtimer_restart tcp_compressed_ack_kick(struct hrtimer *timer)
+{
+ struct tcp_sock *tp = container_of(timer, struct tcp_sock, compressed_ack_timer);
+ struct sock *sk = (struct sock *)tp;
+
+ bh_lock_sock(sk);
+ if (!sock_owned_by_user(sk)) {
+ if (tp->compressed_ack)
+ tcp_send_ack(sk);
+ } else {
+ if (!test_and_set_bit(TCP_DELACK_TIMER_DEFERRED,
+ &sk->sk_tsq_flags))
+ sock_hold(sk);
+ }
+ bh_unlock_sock(sk);
+
+ sock_put(sk);
+
+ return HRTIMER_NORESTART;
+}
+
void tcp_init_xmit_timers(struct sock *sk)
{
inet_csk_init_xmit_timers(sk, &tcp_write_timer, &tcp_delack_timer,
@@ -715,4 +736,8 @@ void tcp_init_xmit_timers(struct sock *sk)
hrtimer_init(&tcp_sk(sk)->pacing_timer, CLOCK_MONOTONIC,
HRTIMER_MODE_ABS_PINNED_SOFT);
tcp_sk(sk)->pacing_timer.function = tcp_pace_kick;
+
+ hrtimer_init(&tcp_sk(sk)->compressed_ack_timer, CLOCK_MONOTONIC,
+ HRTIMER_MODE_REL_PINNED_SOFT);
+ tcp_sk(sk)->compressed_ack_timer.function = tcp_compressed_ack_kick;
}