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authorStephen Hemminger <shemminger@osdl.org>2005-06-23 12:19:55 -0700
committerDavid S. Miller <davem@davemloft.net>2005-06-23 12:19:55 -0700
commit317a76f9a44b437d6301718f4e5d08bd93f98da7 (patch)
treecaeba9839dee264f59b035b81c3d13d6c61b638e /net
parenta8ad86f2dc46356f87be1327dabc18bdbda32f50 (diff)
downloadlinux-stericsson-317a76f9a44b437d6301718f4e5d08bd93f98da7.tar.gz
[TCP]: Add pluggable congestion control algorithm infrastructure.
Allow TCP to have multiple pluggable congestion control algorithms. Algorithms are defined by a set of operations and can be built in or modules. The legacy "new RENO" algorithm is used as a starting point and fallback. Signed-off-by: Stephen Hemminger <shemminger@osdl.org> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net')
-rw-r--r--net/ipv4/Makefile3
-rw-r--r--net/ipv4/sysctl_net_ipv4.c114
-rw-r--r--net/ipv4/tcp.c2
-rw-r--r--net/ipv4/tcp_cong.c195
-rw-r--r--net/ipv4/tcp_diag.c20
-rw-r--r--net/ipv4/tcp_input.c737
-rw-r--r--net/ipv4/tcp_ipv4.c3
-rw-r--r--net/ipv4/tcp_minisocks.c4
-rw-r--r--net/ipv4/tcp_output.c23
-rw-r--r--net/ipv6/tcp_ipv6.c2
10 files changed, 313 insertions, 790 deletions
diff --git a/net/ipv4/Makefile b/net/ipv4/Makefile
index 65d57d8e1add..89c0b4cb470e 100644
--- a/net/ipv4/Makefile
+++ b/net/ipv4/Makefile
@@ -5,7 +5,8 @@
obj-y := utils.o route.o inetpeer.o protocol.o \
ip_input.o ip_fragment.o ip_forward.o ip_options.o \
ip_output.o ip_sockglue.o \
- tcp.o tcp_input.o tcp_output.o tcp_timer.o tcp_ipv4.o tcp_minisocks.o \
+ tcp.o tcp_input.o tcp_output.o tcp_timer.o tcp_ipv4.o \
+ tcp_minisocks.o tcp_cong.o \
datagram.o raw.o udp.o arp.o icmp.o devinet.o af_inet.o igmp.o \
sysctl_net_ipv4.o fib_frontend.o fib_semantics.o
diff --git a/net/ipv4/sysctl_net_ipv4.c b/net/ipv4/sysctl_net_ipv4.c
index 23068bddbf0b..e32894532416 100644
--- a/net/ipv4/sysctl_net_ipv4.c
+++ b/net/ipv4/sysctl_net_ipv4.c
@@ -118,6 +118,45 @@ static int ipv4_sysctl_forward_strategy(ctl_table *table,
return 1;
}
+static int proc_tcp_congestion_control(ctl_table *ctl, int write, struct file * filp,
+ void __user *buffer, size_t *lenp, loff_t *ppos)
+{
+ char val[TCP_CA_NAME_MAX];
+ ctl_table tbl = {
+ .data = val,
+ .maxlen = TCP_CA_NAME_MAX,
+ };
+ int ret;
+
+ tcp_get_default_congestion_control(val);
+
+ ret = proc_dostring(&tbl, write, filp, buffer, lenp, ppos);
+ if (write && ret == 0)
+ ret = tcp_set_default_congestion_control(val);
+ return ret;
+}
+
+int sysctl_tcp_congestion_control(ctl_table *table, int __user *name, int nlen,
+ void __user *oldval, size_t __user *oldlenp,
+ void __user *newval, size_t newlen,
+ void **context)
+{
+ char val[TCP_CA_NAME_MAX];
+ ctl_table tbl = {
+ .data = val,
+ .maxlen = TCP_CA_NAME_MAX,
+ };
+ int ret;
+
+ tcp_get_default_congestion_control(val);
+ ret = sysctl_string(&tbl, name, nlen, oldval, oldlenp, newval, newlen,
+ context);
+ if (ret == 0 && newval && newlen)
+ ret = tcp_set_default_congestion_control(val);
+ return ret;
+}
+
+
ctl_table ipv4_table[] = {
{
.ctl_name = NET_IPV4_TCP_TIMESTAMPS,
@@ -612,70 +651,6 @@ ctl_table ipv4_table[] = {
.proc_handler = &proc_dointvec,
},
{
- .ctl_name = NET_TCP_WESTWOOD,
- .procname = "tcp_westwood",
- .data = &sysctl_tcp_westwood,
- .maxlen = sizeof(int),
- .mode = 0644,
- .proc_handler = &proc_dointvec,
- },
- {
- .ctl_name = NET_TCP_VEGAS,
- .procname = "tcp_vegas_cong_avoid",
- .data = &sysctl_tcp_vegas_cong_avoid,
- .maxlen = sizeof(int),
- .mode = 0644,
- .proc_handler = &proc_dointvec,
- },
- {
- .ctl_name = NET_TCP_VEGAS_ALPHA,
- .procname = "tcp_vegas_alpha",
- .data = &sysctl_tcp_vegas_alpha,
- .maxlen = sizeof(int),
- .mode = 0644,
- .proc_handler = &proc_dointvec,
- },
- {
- .ctl_name = NET_TCP_VEGAS_BETA,
- .procname = "tcp_vegas_beta",
- .data = &sysctl_tcp_vegas_beta,
- .maxlen = sizeof(int),
- .mode = 0644,
- .proc_handler = &proc_dointvec,
- },
- {
- .ctl_name = NET_TCP_VEGAS_GAMMA,
- .procname = "tcp_vegas_gamma",
- .data = &sysctl_tcp_vegas_gamma,
- .maxlen = sizeof(int),
- .mode = 0644,
- .proc_handler = &proc_dointvec,
- },
- {
- .ctl_name = NET_TCP_BIC,
- .procname = "tcp_bic",
- .data = &sysctl_tcp_bic,
- .maxlen = sizeof(int),
- .mode = 0644,
- .proc_handler = &proc_dointvec,
- },
- {
- .ctl_name = NET_TCP_BIC_FAST_CONVERGENCE,
- .procname = "tcp_bic_fast_convergence",
- .data = &sysctl_tcp_bic_fast_convergence,
- .maxlen = sizeof(int),
- .mode = 0644,
- .proc_handler = &proc_dointvec,
- },
- {
- .ctl_name = NET_TCP_BIC_LOW_WINDOW,
- .procname = "tcp_bic_low_window",
- .data = &sysctl_tcp_bic_low_window,
- .maxlen = sizeof(int),
- .mode = 0644,
- .proc_handler = &proc_dointvec,
- },
- {
.ctl_name = NET_TCP_MODERATE_RCVBUF,
.procname = "tcp_moderate_rcvbuf",
.data = &sysctl_tcp_moderate_rcvbuf,
@@ -692,13 +667,14 @@ ctl_table ipv4_table[] = {
.proc_handler = &proc_dointvec,
},
{
- .ctl_name = NET_TCP_BIC_BETA,
- .procname = "tcp_bic_beta",
- .data = &sysctl_tcp_bic_beta,
- .maxlen = sizeof(int),
+ .ctl_name = NET_TCP_CONG_CONTROL,
+ .procname = "tcp_congestion_control",
.mode = 0644,
- .proc_handler = &proc_dointvec,
+ .maxlen = TCP_CA_NAME_MAX,
+ .proc_handler = &proc_tcp_congestion_control,
+ .strategy = &sysctl_tcp_congestion_control,
},
+
{ .ctl_name = 0 }
};
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index 674bbd8cfd36..f3dbc8dc1263 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -2333,6 +2333,8 @@ void __init tcp_init(void)
printk(KERN_INFO "TCP: Hash tables configured "
"(established %d bind %d)\n",
tcp_ehash_size << 1, tcp_bhash_size);
+
+ tcp_register_congestion_control(&tcp_reno);
}
EXPORT_SYMBOL(tcp_accept);
diff --git a/net/ipv4/tcp_cong.c b/net/ipv4/tcp_cong.c
new file mode 100644
index 000000000000..665394a63ae4
--- /dev/null
+++ b/net/ipv4/tcp_cong.c
@@ -0,0 +1,195 @@
+/*
+ * Plugable TCP congestion control support and newReno
+ * congestion control.
+ * Based on ideas from I/O scheduler suport and Web100.
+ *
+ * Copyright (C) 2005 Stephen Hemminger <shemminger@osdl.org>
+ */
+
+#include <linux/config.h>
+#include <linux/module.h>
+#include <linux/mm.h>
+#include <linux/types.h>
+#include <linux/list.h>
+#include <net/tcp.h>
+
+static DEFINE_SPINLOCK(tcp_cong_list_lock);
+static LIST_HEAD(tcp_cong_list);
+
+/* Simple linear search, don't expect many entries! */
+static struct tcp_congestion_ops *tcp_ca_find(const char *name)
+{
+ struct tcp_congestion_ops *e;
+
+ list_for_each_entry(e, &tcp_cong_list, list) {
+ if (strcmp(e->name, name) == 0)
+ return e;
+ }
+
+ return NULL;
+}
+
+/*
+ * Attach new congestion control algorthim to the list
+ * of available options.
+ */
+int tcp_register_congestion_control(struct tcp_congestion_ops *ca)
+{
+ int ret = 0;
+
+ /* all algorithms must implement ssthresh and cong_avoid ops */
+ if (!ca->ssthresh || !ca->cong_avoid || !ca->min_cwnd) {
+ printk(KERN_ERR "TCP %s does not implement required ops\n",
+ ca->name);
+ return -EINVAL;
+ }
+
+ spin_lock(&tcp_cong_list_lock);
+ if (tcp_ca_find(ca->name)) {
+ printk(KERN_NOTICE "TCP %s already registered\n", ca->name);
+ ret = -EEXIST;
+ } else {
+ list_add_rcu(&ca->list, &tcp_cong_list);
+ printk(KERN_INFO "TCP %s registered\n", ca->name);
+ }
+ spin_unlock(&tcp_cong_list_lock);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(tcp_register_congestion_control);
+
+/*
+ * Remove congestion control algorithm, called from
+ * the module's remove function. Module ref counts are used
+ * to ensure that this can't be done till all sockets using
+ * that method are closed.
+ */
+void tcp_unregister_congestion_control(struct tcp_congestion_ops *ca)
+{
+ spin_lock(&tcp_cong_list_lock);
+ list_del_rcu(&ca->list);
+ spin_unlock(&tcp_cong_list_lock);
+}
+EXPORT_SYMBOL_GPL(tcp_unregister_congestion_control);
+
+/* Assign choice of congestion control. */
+void tcp_init_congestion_control(struct tcp_sock *tp)
+{
+ struct tcp_congestion_ops *ca;
+
+ rcu_read_lock();
+ list_for_each_entry_rcu(ca, &tcp_cong_list, list) {
+ if (try_module_get(ca->owner)) {
+ tp->ca_ops = ca;
+ break;
+ }
+
+ }
+ rcu_read_unlock();
+
+ if (tp->ca_ops->init)
+ tp->ca_ops->init(tp);
+}
+
+/* Manage refcounts on socket close. */
+void tcp_cleanup_congestion_control(struct tcp_sock *tp)
+{
+ if (tp->ca_ops->release)
+ tp->ca_ops->release(tp);
+ module_put(tp->ca_ops->owner);
+}
+
+/* Used by sysctl to change default congestion control */
+int tcp_set_default_congestion_control(const char *name)
+{
+ struct tcp_congestion_ops *ca;
+ int ret = -ENOENT;
+
+ spin_lock(&tcp_cong_list_lock);
+ ca = tcp_ca_find(name);
+#ifdef CONFIG_KMOD
+ if (!ca) {
+ spin_unlock(&tcp_cong_list_lock);
+
+ request_module("tcp_%s", name);
+ spin_lock(&tcp_cong_list_lock);
+ ca = tcp_ca_find(name);
+ }
+#endif
+
+ if (ca) {
+ list_move(&ca->list, &tcp_cong_list);
+ ret = 0;
+ }
+ spin_unlock(&tcp_cong_list_lock);
+
+ return ret;
+}
+
+/* Get current default congestion control */
+void tcp_get_default_congestion_control(char *name)
+{
+ struct tcp_congestion_ops *ca;
+ /* We will always have reno... */
+ BUG_ON(list_empty(&tcp_cong_list));
+
+ rcu_read_lock();
+ ca = list_entry(tcp_cong_list.next, struct tcp_congestion_ops, list);
+ strncpy(name, ca->name, TCP_CA_NAME_MAX);
+ rcu_read_unlock();
+}
+
+/*
+ * TCP Reno congestion control
+ * This is special case used for fallback as well.
+ */
+/* This is Jacobson's slow start and congestion avoidance.
+ * SIGCOMM '88, p. 328.
+ */
+void tcp_reno_cong_avoid(struct tcp_sock *tp, u32 ack, u32 rtt, u32 in_flight,
+ int flag)
+{
+ if (in_flight < tp->snd_cwnd)
+ 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++;
+ }
+}
+EXPORT_SYMBOL_GPL(tcp_reno_cong_avoid);
+
+/* Slow start threshold is half the congestion window (min 2) */
+u32 tcp_reno_ssthresh(struct tcp_sock *tp)
+{
+ return max(tp->snd_cwnd >> 1U, 2U);
+}
+EXPORT_SYMBOL_GPL(tcp_reno_ssthresh);
+
+/* Lower bound on congestion window. */
+u32 tcp_reno_min_cwnd(struct tcp_sock *tp)
+{
+ return tp->snd_ssthresh/2;
+}
+EXPORT_SYMBOL_GPL(tcp_reno_min_cwnd);
+
+struct tcp_congestion_ops tcp_reno = {
+ .name = "reno",
+ .owner = THIS_MODULE,
+ .ssthresh = tcp_reno_ssthresh,
+ .cong_avoid = tcp_reno_cong_avoid,
+ .min_cwnd = tcp_reno_min_cwnd,
+};
+
+EXPORT_SYMBOL_GPL(tcp_reno);
diff --git a/net/ipv4/tcp_diag.c b/net/ipv4/tcp_diag.c
index 634befc07921..867acc0f79d8 100644
--- a/net/ipv4/tcp_diag.c
+++ b/net/ipv4/tcp_diag.c
@@ -42,7 +42,6 @@ struct tcpdiag_entry
static struct sock *tcpnl;
-
#define TCPDIAG_PUT(skb, attrtype, attrlen) \
({ int rtalen = RTA_LENGTH(attrlen); \
struct rtattr *rta; \
@@ -61,7 +60,6 @@ static int tcpdiag_fill(struct sk_buff *skb, struct sock *sk,
struct nlmsghdr *nlh;
struct tcp_info *info = NULL;
struct tcpdiag_meminfo *minfo = NULL;
- struct tcpvegas_info *vinfo = NULL;
unsigned char *b = skb->tail;
nlh = NLMSG_PUT(skb, pid, seq, TCPDIAG_GETSOCK, sizeof(*r));
@@ -73,9 +71,6 @@ static int tcpdiag_fill(struct sk_buff *skb, struct sock *sk,
if (ext & (1<<(TCPDIAG_INFO-1)))
info = TCPDIAG_PUT(skb, TCPDIAG_INFO, sizeof(*info));
- if ((tcp_is_westwood(tp) || tcp_is_vegas(tp))
- && (ext & (1<<(TCPDIAG_VEGASINFO-1))))
- vinfo = TCPDIAG_PUT(skb, TCPDIAG_VEGASINFO, sizeof(*vinfo));
}
r->tcpdiag_family = sk->sk_family;
r->tcpdiag_state = sk->sk_state;
@@ -166,19 +161,8 @@ static int tcpdiag_fill(struct sk_buff *skb, struct sock *sk,
if (info)
tcp_get_info(sk, info);
- if (vinfo) {
- if (tcp_is_vegas(tp)) {
- vinfo->tcpv_enabled = tp->vegas.doing_vegas_now;
- vinfo->tcpv_rttcnt = tp->vegas.cntRTT;
- vinfo->tcpv_rtt = jiffies_to_usecs(tp->vegas.baseRTT);
- vinfo->tcpv_minrtt = jiffies_to_usecs(tp->vegas.minRTT);
- } else {
- vinfo->tcpv_enabled = 0;
- vinfo->tcpv_rttcnt = 0;
- vinfo->tcpv_rtt = jiffies_to_usecs(tp->westwood.rtt);
- vinfo->tcpv_minrtt = jiffies_to_usecs(tp->westwood.rtt_min);
- }
- }
+ if (sk->sk_state < TCP_TIME_WAIT && tp->ca_ops->get_info)
+ tp->ca_ops->get_info(tp, ext, skb);
nlh->nlmsg_len = skb->tail - b;
return skb->len;
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index 5bad504630a3..7bbbbc33eb4b 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -61,7 +61,6 @@
* Panu Kuhlberg: Experimental audit of TCP (re)transmission
* engine. Lots of bugs are found.
* Pasi Sarolahti: F-RTO for dealing with spurious RTOs
- * Angelo Dell'Aera: TCP Westwood+ support
*/
#include <linux/config.h>
@@ -88,23 +87,9 @@ int sysctl_tcp_rfc1337;
int sysctl_tcp_max_orphans = NR_FILE;
int sysctl_tcp_frto;
int sysctl_tcp_nometrics_save;
-int sysctl_tcp_westwood;
-int sysctl_tcp_vegas_cong_avoid;
int sysctl_tcp_moderate_rcvbuf = 1;
-/* Default values of the Vegas variables, in fixed-point representation
- * with V_PARAM_SHIFT bits to the right of the binary point.
- */
-#define V_PARAM_SHIFT 1
-int sysctl_tcp_vegas_alpha = 1<<V_PARAM_SHIFT;
-int sysctl_tcp_vegas_beta = 3<<V_PARAM_SHIFT;
-int sysctl_tcp_vegas_gamma = 1<<V_PARAM_SHIFT;
-int sysctl_tcp_bic = 1;
-int sysctl_tcp_bic_fast_convergence = 1;
-int sysctl_tcp_bic_low_window = 14;
-int sysctl_tcp_bic_beta = 819; /* = 819/1024 (BICTCP_BETA_SCALE) */
-
#define FLAG_DATA 0x01 /* Incoming frame contained data. */
#define FLAG_WIN_UPDATE 0x02 /* Incoming ACK was a window update. */
#define FLAG_DATA_ACKED 0x04 /* This ACK acknowledged new data. */
@@ -333,15 +318,6 @@ static void tcp_init_buffer_space(struct sock *sk)
tp->snd_cwnd_stamp = tcp_time_stamp;
}
-static void init_bictcp(struct tcp_sock *tp)
-{
- tp->bictcp.cnt = 0;
-
- tp->bictcp.last_max_cwnd = 0;
- tp->bictcp.last_cwnd = 0;
- tp->bictcp.last_stamp = 0;
-}
-
/* 5. Recalculate window clamp after socket hit its memory bounds. */
static void tcp_clamp_window(struct sock *sk, struct tcp_sock *tp)
{
@@ -558,45 +534,6 @@ static void tcp_event_data_recv(struct sock *sk, struct tcp_sock *tp, struct sk_
tcp_grow_window(sk, tp, skb);
}
-/* When starting a new connection, pin down the current choice of
- * congestion algorithm.
- */
-void tcp_ca_init(struct tcp_sock *tp)
-{
- if (sysctl_tcp_westwood)
- tp->adv_cong = TCP_WESTWOOD;
- else if (sysctl_tcp_bic)
- tp->adv_cong = TCP_BIC;
- else if (sysctl_tcp_vegas_cong_avoid) {
- tp->adv_cong = TCP_VEGAS;
- tp->vegas.baseRTT = 0x7fffffff;
- tcp_vegas_enable(tp);
- }
-}
-
-/* Do RTT sampling needed for Vegas.
- * Basically we:
- * o min-filter RTT samples from within an RTT to get the current
- * propagation delay + queuing delay (we are min-filtering to try to
- * avoid the effects of delayed ACKs)
- * o min-filter RTT samples from a much longer window (forever for now)
- * to find the propagation delay (baseRTT)
- */
-static inline void vegas_rtt_calc(struct tcp_sock *tp, __u32 rtt)
-{
- __u32 vrtt = rtt + 1; /* Never allow zero rtt or baseRTT */
-
- /* Filter to find propagation delay: */
- if (vrtt < tp->vegas.baseRTT)
- tp->vegas.baseRTT = vrtt;
-
- /* Find the min RTT during the last RTT to find
- * the current prop. delay + queuing delay:
- */
- tp->vegas.minRTT = min(tp->vegas.minRTT, vrtt);
- tp->vegas.cntRTT++;
-}
-
/* Called to compute a smoothed rtt estimate. The data fed to this
* routine either comes from timestamps, or from segments that were
* known _not_ to have been retransmitted [see Karn/Partridge
@@ -606,13 +543,10 @@ static inline void vegas_rtt_calc(struct tcp_sock *tp, __u32 rtt)
* 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 tcp_sock *tp, __u32 mrtt)
+static void tcp_rtt_estimator(struct tcp_sock *tp, __u32 mrtt, u32 *usrtt)
{
long m = mrtt; /* RTT */
- if (tcp_vegas_enabled(tp))
- vegas_rtt_calc(tp, mrtt);
-
/* The following amusing code comes from Jacobson's
* article in SIGCOMM '88. Note that rtt and mdev
* are scaled versions of rtt and mean deviation.
@@ -670,7 +604,8 @@ static void tcp_rtt_estimator(struct tcp_sock *tp, __u32 mrtt)
tp->rtt_seq = tp->snd_nxt;
}
- tcp_westwood_update_rtt(tp, tp->srtt >> 3);
+ if (tp->ca_ops->rtt_sample)
+ tp->ca_ops->rtt_sample(tp, *usrtt);
}
/* Calculate rto without backoff. This is the second half of Van Jacobson's
@@ -1185,8 +1120,8 @@ void tcp_enter_frto(struct sock *sk)
tp->snd_una == tp->high_seq ||
(tp->ca_state == TCP_CA_Loss && !tp->retransmits)) {
tp->prior_ssthresh = tcp_current_ssthresh(tp);
- if (!tcp_westwood_ssthresh(tp))
- tp->snd_ssthresh = tcp_recalc_ssthresh(tp);
+ tp->snd_ssthresh = tp->ca_ops->ssthresh(tp);
+ tcp_ca_event(tp, CA_EVENT_FRTO);
}
/* Have to clear retransmission markers here to keep the bookkeeping
@@ -1252,8 +1187,6 @@ static void tcp_enter_frto_loss(struct sock *sk)
tcp_set_ca_state(tp, TCP_CA_Loss);
tp->high_seq = tp->frto_highmark;
TCP_ECN_queue_cwr(tp);
-
- init_bictcp(tp);
}
void tcp_clear_retrans(struct tcp_sock *tp)
@@ -1283,7 +1216,8 @@ void tcp_enter_loss(struct sock *sk, int how)
if (tp->ca_state <= TCP_CA_Disorder || tp->snd_una == tp->high_seq ||
(tp->ca_state == TCP_CA_Loss && !tp->retransmits)) {
tp->prior_ssthresh = tcp_current_ssthresh(tp);
- tp->snd_ssthresh = tcp_recalc_ssthresh(tp);
+ tp->snd_ssthresh = tp->ca_ops->ssthresh(tp);
+ tcp_ca_event(tp, CA_EVENT_LOSS);
}
tp->snd_cwnd = 1;
tp->snd_cwnd_cnt = 0;
@@ -1596,28 +1530,14 @@ static inline void tcp_moderate_cwnd(struct tcp_sock *tp)
}
/* Decrease cwnd each second ack. */
-
static void tcp_cwnd_down(struct tcp_sock *tp)
{
int decr = tp->snd_cwnd_cnt + 1;
- __u32 limit;
-
- /*
- * TCP Westwood
- * Here limit is evaluated as BWestimation*RTTmin (for obtaining it
- * in packets we use mss_cache). If sysctl_tcp_westwood is off
- * tcp_westwood_bw_rttmin() returns 0. In such case snd_ssthresh is
- * still used as usual. It prevents other strange cases in which
- * BWE*RTTmin could assume value 0. It should not happen but...
- */
-
- if (!(limit = tcp_westwood_bw_rttmin(tp)))
- limit = tp->snd_ssthresh/2;
tp->snd_cwnd_cnt = decr&1;
decr >>= 1;
- if (decr && tp->snd_cwnd > limit)
+ if (decr && tp->snd_cwnd > tp->ca_ops->min_cwnd(tp))
tp->snd_cwnd -= decr;
tp->snd_cwnd = min(tp->snd_cwnd, tcp_packets_in_flight(tp)+1);
@@ -1654,8 +1574,8 @@ static void DBGUNDO(struct sock *sk, struct tcp_sock *tp, const char *msg)
static void tcp_undo_cwr(struct tcp_sock *tp, int undo)
{
if (tp->prior_ssthresh) {
- if (tcp_is_bic(tp))
- tp->snd_cwnd = max(tp->snd_cwnd, tp->bictcp.last_max_cwnd);
+ if (tp->ca_ops->undo_cwnd)
+ tp->snd_cwnd = tp->ca_ops->undo_cwnd(tp);
else
tp->snd_cwnd = max(tp->snd_cwnd, tp->snd_ssthresh<<1);
@@ -1767,11 +1687,9 @@ static int tcp_try_undo_loss(struct sock *sk, struct tcp_sock *tp)
static inline void tcp_complete_cwr(struct tcp_sock *tp)
{
- if (tcp_westwood_cwnd(tp))
- tp->snd_ssthresh = tp->snd_cwnd;
- else
- tp->snd_cwnd = min(tp->snd_cwnd, tp->snd_ssthresh);
+ tp->snd_cwnd = min(tp->snd_cwnd, tp->snd_ssthresh);
tp->snd_cwnd_stamp = tcp_time_stamp;
+ tcp_ca_event(tp, CA_EVENT_COMPLETE_CWR);
}
static void tcp_try_to_open(struct sock *sk, struct tcp_sock *tp, int flag)
@@ -1946,7 +1864,7 @@ tcp_fastretrans_alert(struct sock *sk, u32 prior_snd_una,
if (tp->ca_state < TCP_CA_CWR) {
if (!(flag&FLAG_ECE))
tp->prior_ssthresh = tcp_current_ssthresh(tp);
- tp->snd_ssthresh = tcp_recalc_ssthresh(tp);
+ tp->snd_ssthresh = tp->ca_ops->ssthresh(tp);
TCP_ECN_queue_cwr(tp);
}
@@ -1963,7 +1881,7 @@ tcp_fastretrans_alert(struct sock *sk, u32 prior_snd_una,
/* Read draft-ietf-tcplw-high-performance before mucking
* with this code. (Superceeds RFC1323)
*/
-static void tcp_ack_saw_tstamp(struct tcp_sock *tp, int flag)
+static void tcp_ack_saw_tstamp(struct tcp_sock *tp, u32 *usrtt, int flag)
{
__u32 seq_rtt;
@@ -1983,13 +1901,13 @@ static void tcp_ack_saw_tstamp(struct tcp_sock *tp, int flag)
* in window is lost... Voila. --ANK (010210)
*/
seq_rtt = tcp_time_stamp - tp->rx_opt.rcv_tsecr;
- tcp_rtt_estimator(tp, seq_rtt);
+ tcp_rtt_estimator(tp, seq_rtt, usrtt);
tcp_set_rto(tp);
tp->backoff = 0;
tcp_bound_rto(tp);
}
-static void tcp_ack_no_tstamp(struct tcp_sock *tp, u32 seq_rtt, int flag)
+static void tcp_ack_no_tstamp(struct tcp_sock *tp, u32 seq_rtt, u32 *usrtt, int flag)
{
/* We don't have a timestamp. Can only use
* packets that are not retransmitted to determine
@@ -2003,338 +1921,29 @@ static void tcp_ack_no_tstamp(struct tcp_sock *tp, u32 seq_rtt, int flag)
if (flag & FLAG_RETRANS_DATA_ACKED)
return;
- tcp_rtt_estimator(tp, seq_rtt);
+ tcp_rtt_estimator(tp, seq_rtt, usrtt);
tcp_set_rto(tp);
tp->backoff = 0;
tcp_bound_rto(tp);
}
static inline void tcp_ack_update_rtt(struct tcp_sock *tp,
- int flag, s32 seq_rtt)
+ int flag, s32 seq_rtt, u32 *usrtt)
{
/* 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(tp, flag);
+ tcp_ack_saw_tstamp(tp, usrtt, flag);
else if (seq_rtt >= 0)
- tcp_ack_no_tstamp(tp, seq_rtt, flag);
+ tcp_ack_no_tstamp(tp, seq_rtt, usrtt, flag);
}
-/*
- * Compute congestion window to use.
- *
- * This is from the implementation of BICTCP in
- * Lison-Xu, Kahaled Harfoush, and Injog Rhee.
- * "Binary Increase Congestion Control for Fast, Long Distance
- * Networks" in InfoComm 2004
- * Available from:
- * http://www.csc.ncsu.edu/faculty/rhee/export/bitcp.pdf
- *
- * Unless BIC is enabled and congestion window is large
- * this behaves the same as the original Reno.
- */
-static inline __u32 bictcp_cwnd(struct tcp_sock *tp)
-{
- /* orignal Reno behaviour */
- if (!tcp_is_bic(tp))
- return tp->snd_cwnd;
-
- if (tp->bictcp.last_cwnd == tp->snd_cwnd &&
- (s32)(tcp_time_stamp - tp->bictcp.last_stamp) <= (HZ>>5))
- return tp->bictcp.cnt;
-
- tp->bictcp.last_cwnd = tp->snd_cwnd;
- tp->bictcp.last_stamp = tcp_time_stamp;
-
- /* start off normal */
- if (tp->snd_cwnd <= sysctl_tcp_bic_low_window)
- tp->bictcp.cnt = tp->snd_cwnd;
-
- /* binary increase */
- else if (tp->snd_cwnd < tp->bictcp.last_max_cwnd) {
- __u32 dist = (tp->bictcp.last_max_cwnd - tp->snd_cwnd)
- / BICTCP_B;
-
- if (dist > BICTCP_MAX_INCREMENT)
- /* linear increase */
- tp->bictcp.cnt = tp->snd_cwnd / BICTCP_MAX_INCREMENT;
- else if (dist <= 1U)
- /* binary search increase */
- tp->bictcp.cnt = tp->snd_cwnd * BICTCP_FUNC_OF_MIN_INCR
- / BICTCP_B;
- else
- /* binary search increase */
- tp->bictcp.cnt = tp->snd_cwnd / dist;
- } else {
- /* slow start amd linear increase */
- if (tp->snd_cwnd < tp->bictcp.last_max_cwnd + BICTCP_B)
- /* slow start */
- tp->bictcp.cnt = tp->snd_cwnd * BICTCP_FUNC_OF_MIN_INCR
- / BICTCP_B;
- else if (tp->snd_cwnd < tp->bictcp.last_max_cwnd
- + BICTCP_MAX_INCREMENT*(BICTCP_B-1))
- /* slow start */
- tp->bictcp.cnt = tp->snd_cwnd * (BICTCP_B-1)
- / (tp->snd_cwnd-tp->bictcp.last_max_cwnd);
- else
- /* linear increase */
- tp->bictcp.cnt = tp->snd_cwnd / BICTCP_MAX_INCREMENT;
- }
- return tp->bictcp.cnt;
-}
-
-/* This is Jacobson's slow start and congestion avoidance.
- * SIGCOMM '88, p. 328.
- */
-static inline void reno_cong_avoid(struct tcp_sock *tp)
+static inline void tcp_cong_avoid(struct tcp_sock *tp, u32 ack, u32 rtt,
+ u32 in_flight, int good)
{
- 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 >= bictcp_cwnd(tp)) {
- if (tp->snd_cwnd < tp->snd_cwnd_clamp)
- tp->snd_cwnd++;
- tp->snd_cwnd_cnt=0;
- } else
- tp->snd_cwnd_cnt++;
- }
+ tp->ca_ops->cong_avoid(tp, ack, rtt, in_flight, good);
tp->snd_cwnd_stamp = tcp_time_stamp;
}
-/* This is based on the congestion detection/avoidance scheme described in
- * Lawrence S. Brakmo and Larry L. Peterson.
- * "TCP Vegas: End to end congestion avoidance on a global internet."
- * IEEE Journal on Selected Areas in Communication, 13(8):1465--1480,
- * October 1995. Available from:
- * ftp://ftp.cs.arizona.edu/xkernel/Papers/jsac.ps
- *
- * See http://www.cs.arizona.edu/xkernel/ for their implementation.
- * The main aspects that distinguish this implementation from the
- * Arizona Vegas implementation are:
- * o We do not change the loss detection or recovery mechanisms of
- * Linux in any way. Linux already recovers from losses quite well,
- * using fine-grained timers, NewReno, and FACK.
- * o To avoid the performance penalty imposed by increasing cwnd
- * only every-other RTT during slow start, we increase during
- * every RTT during slow start, just like Reno.
- * o Largely to allow continuous cwnd growth during slow start,
- * we use the rate at which ACKs come back as the "actual"
- * rate, rather than the rate at which data is sent.
- * o To speed convergence to the right rate, we set the cwnd
- * to achieve the right ("actual") rate when we exit slow start.
- * o To filter out the noise caused by delayed ACKs, we use the
- * minimum RTT sample observed during the last RTT to calculate
- * the actual rate.
- * o When the sender re-starts from idle, it waits until it has
- * received ACKs for an entire flight of new data before making
- * a cwnd adjustment decision. The original Vegas implementation
- * assumed senders never went idle.
- */
-static void vegas_cong_avoid(struct tcp_sock *tp, u32 ack, u32 seq_rtt)
-{
- /* The key players are v_beg_snd_una and v_beg_snd_nxt.
- *
- * These are so named because they represent the approximate values
- * of snd_una and snd_nxt at the beginning of the current RTT. More
- * precisely, they represent the amount of data sent during the RTT.
- * At the end of the RTT, when we receive an ACK for v_beg_snd_nxt,
- * we will calculate that (v_beg_snd_nxt - v_beg_snd_una) outstanding
- * bytes of data have been ACKed during the course of the RTT, giving
- * an "actual" rate of:
- *
- * (v_beg_snd_nxt - v_beg_snd_una) / (rtt duration)
- *
- * Unfortunately, v_beg_snd_una is not exactly equal to snd_una,
- * because delayed ACKs can cover more than one segment, so they
- * don't line up nicely with the boundaries of RTTs.
- *
- * Another unfortunate fact of life is that delayed ACKs delay the
- * advance of the left edge of our send window, so that the number
- * of bytes we send in an RTT is often less than our cwnd will allow.
- * So we keep track of our cwnd separately, in v_beg_snd_cwnd.
- */
-
- if (after(ack, tp->vegas.beg_snd_nxt)) {
- /* Do the Vegas once-per-RTT cwnd adjustment. */
- u32 old_wnd, old_snd_cwnd;
-
-
- /* Here old_wnd is essentially the window of data that was
- * sent during the previous RTT, and has all
- * been acknowledged in the course of the RTT that ended
- * with the ACK we just received. Likewise, old_snd_cwnd
- * is the cwnd during the previous RTT.
- */
- old_wnd = (tp->vegas.beg_snd_nxt - tp->vegas.beg_snd_una) /
- tp->mss_cache_std;
- old_snd_cwnd = tp->vegas.beg_snd_cwnd;
-
- /* Save the extent of the current window so we can use this
- * at the end of the next RTT.
- */
- tp->vegas.beg_snd_una = tp->vegas.beg_snd_nxt;
- tp->vegas.beg_snd_nxt = tp->snd_nxt;
- tp->vegas.beg_snd_cwnd = tp->snd_cwnd;
-
- /* Take into account the current RTT sample too, to
- * decrease the impact of delayed acks. This double counts
- * this sample since we count it for the next window as well,
- * but that's not too awful, since we're taking the min,
- * rather than averaging.
- */
- vegas_rtt_calc(tp, seq_rtt);
-
- /* We do the Vegas calculations only if we got enough RTT
- * samples that we can be reasonably sure that we got
- * at least one RTT sample that wasn't from a delayed ACK.
- * If we only had 2 samples total,
- * then that means we're getting only 1 ACK per RTT, which
- * means they're almost certainly delayed ACKs.
- * If we have 3 samples, we should be OK.
- */
-
- if (tp->vegas.cntRTT <= 2) {
- /* 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++;
- } else {
- u32 rtt, target_cwnd, diff;
-
- /* We have enough RTT samples, so, using the Vegas
- * algorithm, we determine if we should increase or
- * decrease cwnd, and by how much.
- */
-
- /* Pluck out the RTT we are using for the Vegas
- * calculations. This is the min RTT seen during the
- * last RTT. Taking the min filters out the effects
- * of delayed ACKs, at the cost of noticing congestion
- * a bit later.
- */
- rtt = tp->vegas.minRTT;
-
- /* Calculate the cwnd we should have, if we weren't
- * going too fast.
- *
- * This is:
- * (actual rate in segments) * baseRTT
- * We keep it as a fixed point number with
- * V_PARAM_SHIFT bits to the right of the binary point.
- */
- target_cwnd = ((old_wnd * tp->vegas.baseRTT)
- << V_PARAM_SHIFT) / rtt;
-
- /* Calculate the difference between the window we had,
- * and the window we would like to have. This quantity
- * is the "Diff" from the Arizona Vegas papers.
- *
- * Again, this is a fixed point number with
- * V_PARAM_SHIFT bits to the right of the binary
- * point.
- */
- diff = (old_wnd << V_PARAM_SHIFT) - target_cwnd;
-
- if (tp->snd_cwnd < tp->snd_ssthresh) {
- /* Slow start. */
- if (diff > sysctl_tcp_vegas_gamma) {
- /* Going too fast. Time to slow down
- * and switch to congestion avoidance.
- */
- tp->snd_ssthresh = 2;
-
- /* Set cwnd to match the actual rate
- * exactly:
- * cwnd = (actual rate) * baseRTT
- * Then we add 1 because the integer
- * truncation robs us of full link
- * utilization.
- */
- tp->snd_cwnd = min(tp->snd_cwnd,
- (target_cwnd >>
- V_PARAM_SHIFT)+1);
-
- }
- } else {
- /* Congestion avoidance. */
- u32 next_snd_cwnd;
-
- /* Figure out where we would like cwnd
- * to be.
- */
- if (diff > sysctl_tcp_vegas_beta) {
- /* The old window was too fast, so
- * we slow down.
- */
- next_snd_cwnd = old_snd_cwnd - 1;
- } else if (diff < sysctl_tcp_vegas_alpha) {
- /* We don't have enough extra packets
- * in the network, so speed up.
- */
- next_snd_cwnd = old_snd_cwnd + 1;
- } else {
- /* Sending just as fast as we
- * should be.
- */
- next_snd_cwnd = old_snd_cwnd;
- }
-
- /* Adjust cwnd upward or downward, toward the
- * desired value.
- */
- if (next_snd_cwnd > tp->snd_cwnd)
- tp->snd_cwnd++;
- else if (next_snd_cwnd < tp->snd_cwnd)
- tp->snd_cwnd--;
- }
- }
-
- /* Wipe the slate clean for the next RTT. */
- tp->vegas.cntRTT = 0;
- tp->vegas.minRTT = 0x7fffffff;
- }
-
- /* 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);
-
- tp->snd_cwnd_stamp = tcp_time_stamp;
-}
-
-static inline void tcp_cong_avoid(struct tcp_sock *tp, u32 ack, u32 seq_rtt)
-{
- if (tcp_vegas_enabled(tp))
- vegas_cong_avoid(tp, ack, seq_rtt);
- else
- reno_cong_avoid(tp);
-}
-
/* Restart timer after forward progress on connection.
* RFC2988 recommends to restart timer to now+rto.
*/
@@ -2415,13 +2024,18 @@ static int tcp_tso_acked(struct sock *sk, struct sk_buff *skb,
/* Remove acknowledged frames from the retransmission queue. */
-static int tcp_clean_rtx_queue(struct sock *sk, __s32 *seq_rtt_p)
+static int tcp_clean_rtx_queue(struct sock *sk, __s32 *seq_rtt_p, s32 *seq_usrtt)
{
struct tcp_sock *tp = tcp_sk(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);
while ((skb = skb_peek(&sk->sk_write_queue)) &&
skb != sk->sk_send_head) {
@@ -2448,6 +2062,7 @@ static int tcp_clean_rtx_queue(struct sock *sk, __s32 *seq_rtt_p)
*/
if (!(scb->flags & TCPCB_FLAG_SYN)) {
acked |= FLAG_DATA_ACKED;
+ ++pkts_acked;
} else {
acked |= FLAG_SYN_ACKED;
tp->retrans_stamp = 0;
@@ -2461,6 +2076,10 @@ static int tcp_clean_rtx_queue(struct sock *sk, __s32 *seq_rtt_p)
seq_rtt = -1;
} else if (seq_rtt < 0)
seq_rtt = now - scb->when;
+ if (seq_usrtt)
+ *seq_usrtt = (usnow.tv_sec - skb->stamp.tv_sec) * 1000000
+ + (usnow.tv_usec - skb->stamp.tv_usec);
+
if (sacked & TCPCB_SACKED_ACKED)
tp->sacked_out -= tcp_skb_pcount(skb);
if (sacked & TCPCB_LOST)
@@ -2479,8 +2098,11 @@ static int tcp_clean_rtx_queue(struct sock *sk, __s32 *seq_rtt_p)
}
if (acked&FLAG_ACKED) {
- tcp_ack_update_rtt(tp, acked, seq_rtt);
+ tcp_ack_update_rtt(tp, acked, seq_rtt, seq_usrtt);
tcp_ack_packets_out(sk, tp);
+
+ if (tp->ca_ops->pkts_acked)
+ tp->ca_ops->pkts_acked(tp, pkts_acked);
}
#if FASTRETRANS_DEBUG > 0
@@ -2624,257 +2246,6 @@ static void tcp_process_frto(struct sock *sk, u32 prior_snd_una)
tp->frto_counter = (tp->frto_counter + 1) % 3;
}
-/*
- * TCP Westwood+
- */
-
-/*
- * @init_westwood
- * This function initializes fields used in TCP Westwood+. We can't
- * get no information about RTTmin at this time so we simply set it to
- * TCP_WESTWOOD_INIT_RTT. This value was chosen to be too conservative
- * since in this way we're sure it will be updated in a consistent
- * way as soon as possible. It will reasonably happen within the first
- * RTT period of the connection lifetime.
- */
-
-static void init_westwood(struct sock *sk)
-{
- struct tcp_sock *tp = tcp_sk(sk);
-
- tp->westwood.bw_ns_est = 0;
- tp->westwood.bw_est = 0;
- tp->westwood.accounted = 0;
- tp->westwood.cumul_ack = 0;
- tp->westwood.rtt_win_sx = tcp_time_stamp;
- tp->westwood.rtt = TCP_WESTWOOD_INIT_RTT;
- tp->westwood.rtt_min = TCP_WESTWOOD_INIT_RTT;
- tp->westwood.snd_una = tp->snd_una;
-}
-
-/*
- * @westwood_do_filter
- * Low-pass filter. Implemented using constant coeffients.
- */
-
-static inline __u32 westwood_do_filter(__u32 a, __u32 b)
-{
- return (((7 * a) + b) >> 3);
-}
-
-static void westwood_filter(struct sock *sk, __u32 delta)
-{
- struct tcp_sock *tp = tcp_sk(sk);
-
- tp->westwood.bw_ns_est =
- westwood_do_filter(tp->westwood.bw_ns_est,
- tp->westwood.bk / delta);
- tp->westwood.bw_est =
- westwood_do_filter(tp->westwood.bw_est,
- tp->westwood.bw_ns_est);
-}
-
-/*
- * @westwood_update_rttmin
- * It is used to update RTTmin. In this case we MUST NOT use
- * WESTWOOD_RTT_MIN minimum bound since we could be on a LAN!
- */
-
-static inline __u32 westwood_update_rttmin(const struct sock *sk)
-{
- const struct tcp_sock *tp = tcp_sk(sk);
- __u32 rttmin = tp->westwood.rtt_min;
-
- if (tp->westwood.rtt != 0 &&
- (tp->westwood.rtt < tp->westwood.rtt_min || !rttmin))
- rttmin = tp->westwood.rtt;
-
- return rttmin;
-}
-
-/*
- * @westwood_acked
- * Evaluate increases for dk.
- */
-
-static inline __u32 westwood_acked(const struct sock *sk)
-{
- const struct tcp_sock *tp = tcp_sk(sk);
-
- return tp->snd_una - tp->westwood.snd_una;
-}
-
-/*
- * @westwood_new_window
- * It evaluates if we are receiving data inside the same RTT window as
- * when we started.
- * Return value:
- * It returns 0 if we are still evaluating samples in the same RTT
- * window, 1 if the sample has to be considered in the next window.
- */
-
-static int westwood_new_window(const struct sock *sk)
-{
- const struct tcp_sock *tp = tcp_sk(sk);
- __u32 left_bound;
- __u32 rtt;
- int ret = 0;
-
- left_bound = tp->westwood.rtt_win_sx;
- rtt = max(tp->westwood.rtt, (u32) TCP_WESTWOOD_RTT_MIN);
-
- /*
- * A RTT-window has passed. Be careful since if RTT is less than
- * 50ms we don't filter but we continue 'building the sample'.
- * This minimum limit was choosen since an estimation on small
- * time intervals is better to avoid...
- * Obvioulsy on a LAN we reasonably will always have
- * right_bound = left_bound + WESTWOOD_RTT_MIN
- */
-
- if ((left_bound + rtt) < tcp_time_stamp)
- ret = 1;
-
- return ret;
-}
-
-/*
- * @westwood_update_window
- * It updates RTT evaluation window if it is the right moment to do
- * it. If so it calls filter for evaluating bandwidth.
- */
-
-static void __westwood_update_window(struct sock *sk, __u32 now)
-{
- struct tcp_sock *tp = tcp_sk(sk);
- __u32 delta = now - tp->westwood.rtt_win_sx;
-
- if (delta) {
- if (tp->westwood.rtt)
- westwood_filter(sk, delta);
-
- tp->westwood.bk = 0;
- tp->westwood.rtt_win_sx = tcp_time_stamp;
- }
-}
-
-
-static void westwood_update_window(struct sock *sk, __u32 now)
-{
- if (westwood_new_window(sk))
- __westwood_update_window(sk, now);
-}
-
-/*
- * @__tcp_westwood_fast_bw
- * It is called when we are in fast path. In particular it is called when
- * header prediction is successfull. In such case infact update is
- * straight forward and doesn't need any particular care.
- */
-
-static void __tcp_westwood_fast_bw(struct sock *sk, struct sk_buff *skb)
-{
- struct tcp_sock *tp = tcp_sk(sk);
-
- westwood_update_window(sk, tcp_time_stamp);
-
- tp->westwood.bk += westwood_acked(sk);
- tp->westwood.snd_una = tp->snd_una;
- tp->westwood.rtt_min = westwood_update_rttmin(sk);
-}
-
-static inline void tcp_westwood_fast_bw(struct sock *sk, struct sk_buff *skb)
-{
- if (tcp_is_westwood(tcp_sk(sk)))
- __tcp_westwood_fast_bw(sk, skb);
-}
-
-
-/*
- * @westwood_dupack_update
- * It updates accounted and cumul_ack when receiving a dupack.
- */
-
-static void westwood_dupack_update(struct sock *sk)
-{
- struct tcp_sock *tp = tcp_sk(sk);
-
- tp->westwood.accounted += tp->mss_cache_std;
- tp->westwood.cumul_ack = tp->mss_cache_std;
-}
-
-static inline int westwood_may_change_cumul(struct tcp_sock *tp)
-{
- return (tp->westwood.cumul_ack > tp->mss_cache_std);
-}
-
-static inline void westwood_partial_update(struct tcp_sock *tp)
-{
- tp->westwood.accounted -= tp->westwood.cumul_ack;
- tp->westwood.cumul_ack = tp->mss_cache_std;
-}
-
-static inline void westwood_complete_update(struct tcp_sock *tp)
-{
- tp->westwood.cumul_ack -= tp->westwood.accounted;
- tp->westwood.accounted = 0;
-}
-
-/*
- * @westwood_acked_count
- * This function evaluates cumul_ack for evaluating dk in case of
- * delayed or partial acks.
- */
-
-static inline __u32 westwood_acked_count(struct sock *sk)
-{
- struct tcp_sock *tp = tcp_sk(sk);
-
- tp->westwood.cumul_ack = westwood_acked(sk);
-
- /* If cumul_ack is 0 this is a dupack since it's not moving
- * tp->snd_una.
- */
- if (!(tp->westwood.cumul_ack))
- westwood_dupack_update(sk);
-
- if (westwood_may_change_cumul(tp)) {
- /* Partial or delayed ack */
- if (tp->westwood.accounted >= tp->westwood.cumul_ack)
- westwood_partial_update(tp);
- else
- westwood_complete_update(tp);
- }
-
- tp->westwood.snd_una = tp->snd_una;
-
- return tp->westwood.cumul_ack;
-}
-
-
-/*
- * @__tcp_westwood_slow_bw
- * It is called when something is going wrong..even if there could
- * be no problems! Infact a simple delayed packet may trigger a
- * dupack. But we need to be careful in such case.
- */
-
-static void __tcp_westwood_slow_bw(struct sock *sk, struct sk_buff *skb)
-{
- struct tcp_sock *tp = tcp_sk(sk);
-
- westwood_update_window(sk, tcp_time_stamp);
-
- tp->westwood.bk += westwood_acked_count(sk);
- tp->westwood.rtt_min = westwood_update_rttmin(sk);
-}
-
-static inline void tcp_westwood_slow_bw(struct sock *sk, struct sk_buff *skb)
-{
- if (tcp_is_westwood(tcp_sk(sk)))
- __tcp_westwood_slow_bw(sk, skb);
-}
-
/* This routine deals with incoming acks, but not outgoing ones. */
static int tcp_ack(struct sock *sk, struct sk_buff *skb, int flag)
{
@@ -2884,6 +2255,7 @@ 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
@@ -2902,9 +2274,10 @@ static int tcp_ack(struct sock *sk, struct sk_buff *skb, int flag)
*/
tcp_update_wl(tp, ack, ack_seq);
tp->snd_una = ack;
- tcp_westwood_fast_bw(sk, skb);
flag |= FLAG_WIN_UPDATE;
+ tcp_ca_event(tp, CA_EVENT_FAST_ACK);
+
NET_INC_STATS_BH(LINUX_MIB_TCPHPACKS);
} else {
if (ack_seq != TCP_SKB_CB(skb)->end_seq)
@@ -2920,7 +2293,7 @@ static int tcp_ack(struct sock *sk, struct sk_buff *skb, int flag)
if (TCP_ECN_rcv_ecn_echo(tp, skb->h.th))
flag |= FLAG_ECE;
- tcp_westwood_slow_bw(sk,skb);
+ tcp_ca_event(tp, CA_EVENT_SLOW_ACK);
}
/* We passed data and got it acked, remove any soft error
@@ -2935,22 +2308,20 @@ 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);
+ flag |= tcp_clean_rtx_queue(sk, &seq_rtt,
+ tp->ca_ops->rtt_sample ? &seq_usrtt : NULL);
if (tp->frto_counter)
tcp_process_frto(sk, prior_snd_una);
if (tcp_ack_is_dubious(tp, flag)) {
/* Advanve CWND, if state allows this. */
- if ((flag & FLAG_DATA_ACKED) &&
- (tcp_vegas_enabled(tp) || prior_in_flight >= tp->snd_cwnd) &&
- tcp_may_raise_cwnd(tp, flag))
- tcp_cong_avoid(tp, ack, seq_rtt);
+ if ((flag & FLAG_DATA_ACKED) && tcp_may_raise_cwnd(tp, flag))
+ tcp_cong_avoid(tp, ack, seq_rtt, prior_in_flight, 0);
tcp_fastretrans_alert(sk, prior_snd_una, prior_packets, flag);
} else {
- if ((flag & FLAG_DATA_ACKED) &&
- (tcp_vegas_enabled(tp) || prior_in_flight >= tp->snd_cwnd))
- tcp_cong_avoid(tp, ack, seq_rtt);
+ if ((flag & FLAG_DATA_ACKED))
+ tcp_cong_avoid(tp, ack, seq_rtt, prior_in_flight, 1);
}
if ((flag & FLAG_FORWARD_PROGRESS) || !(flag&FLAG_NOT_DUP))
@@ -4552,6 +3923,8 @@ static int tcp_rcv_synsent_state_process(struct sock *sk, struct sk_buff *skb,
tcp_init_metrics(sk);
+ tcp_init_congestion_control(tp);
+
/* Prevent spurious tcp_cwnd_restart() on first data
* packet.
*/
@@ -4708,9 +4081,6 @@ int tcp_rcv_state_process(struct sock *sk, struct sk_buff *skb,
if(tp->af_specific->conn_request(sk, skb) < 0)
return 1;
- init_westwood(sk);
- init_bictcp(tp);
-
/* Now we have several options: In theory there is
* nothing else in the frame. KA9Q has an option to
* send data with the syn, BSD accepts data with the
@@ -4732,9 +4102,6 @@ int tcp_rcv_state_process(struct sock *sk, struct sk_buff *skb,
goto discard;
case TCP_SYN_SENT:
- init_westwood(sk);
- init_bictcp(tp);
-
queued = tcp_rcv_synsent_state_process(sk, skb, th, len);
if (queued >= 0)
return queued;
@@ -4816,7 +4183,7 @@ 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(tp, 0);
+ tcp_ack_saw_tstamp(tp, 0, 0);
if (tp->rx_opt.tstamp_ok)
tp->advmss -= TCPOLEN_TSTAMP_ALIGNED;
@@ -4828,6 +4195,8 @@ int tcp_rcv_state_process(struct sock *sk, struct sk_buff *skb,
tcp_init_metrics(sk);
+ tcp_init_congestion_control(tp);
+
/* Prevent spurious tcp_cwnd_restart() on
* first data packet.
*/
diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index 2d41d5d6ad19..9122814c13ad 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -2048,6 +2048,7 @@ static int tcp_v4_init_sock(struct sock *sk)
tp->mss_cache_std = tp->mss_cache = 536;
tp->reordering = sysctl_tcp_reordering;
+ tp->ca_ops = &tcp_reno;
sk->sk_state = TCP_CLOSE;
@@ -2070,6 +2071,8 @@ int tcp_v4_destroy_sock(struct sock *sk)
tcp_clear_xmit_timers(sk);
+ tcp_cleanup_congestion_control(tp);
+
/* Cleanup up the write buffer. */
sk_stream_writequeue_purge(sk);
diff --git a/net/ipv4/tcp_minisocks.c b/net/ipv4/tcp_minisocks.c
index b3943e7562f3..f42a284164b7 100644
--- a/net/ipv4/tcp_minisocks.c
+++ b/net/ipv4/tcp_minisocks.c
@@ -774,6 +774,8 @@ struct sock *tcp_create_openreq_child(struct sock *sk, struct request_sock *req,
newtp->frto_counter = 0;
newtp->frto_highmark = 0;
+ newtp->ca_ops = &tcp_reno;
+
tcp_set_ca_state(newtp, TCP_CA_Open);
tcp_init_xmit_timers(newsk);
skb_queue_head_init(&newtp->out_of_order_queue);
@@ -842,8 +844,6 @@ struct sock *tcp_create_openreq_child(struct sock *sk, struct request_sock *req,
if (newtp->ecn_flags&TCP_ECN_OK)
sock_set_flag(newsk, SOCK_NO_LARGESEND);
- tcp_ca_init(newtp);
-
TCP_INC_STATS_BH(TCP_MIB_PASSIVEOPENS);
}
return newsk;
diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index f17c6577e337..0e17c244875c 100644
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -111,8 +111,7 @@ static void tcp_cwnd_restart(struct tcp_sock *tp, struct dst_entry *dst)
u32 restart_cwnd = tcp_init_cwnd(tp, dst);
u32 cwnd = tp->snd_cwnd;
- if (tcp_is_vegas(tp))
- tcp_vegas_enable(tp);
+ tcp_ca_event(tp, CA_EVENT_CWND_RESTART);
tp->snd_ssthresh = tcp_current_ssthresh(tp);
restart_cwnd = min(restart_cwnd, cwnd);
@@ -280,6 +279,10 @@ static int tcp_transmit_skb(struct sock *sk, struct sk_buff *skb)
#define SYSCTL_FLAG_WSCALE 0x2
#define SYSCTL_FLAG_SACK 0x4
+ /* If congestion control is doing timestamping */
+ if (tp->ca_ops->rtt_sample)
+ do_gettimeofday(&skb->stamp);
+
sysctl_flags = 0;
if (tcb->flags & TCPCB_FLAG_SYN) {
tcp_header_size = sizeof(struct tcphdr) + TCPOLEN_MSS;
@@ -304,17 +307,8 @@ static int tcp_transmit_skb(struct sock *sk, struct sk_buff *skb)
(tp->rx_opt.eff_sacks * TCPOLEN_SACK_PERBLOCK));
}
- /*
- * If the connection is idle and we are restarting,
- * then we don't want to do any Vegas calculations
- * until we get fresh RTT samples. So when we
- * restart, we reset our Vegas state to a clean
- * slate. After we get acks for this flight of
- * packets, _then_ we can make Vegas calculations
- * again.
- */
- if (tcp_is_vegas(tp) && tcp_packets_in_flight(tp) == 0)
- tcp_vegas_enable(tp);
+ if (tcp_packets_in_flight(tp) == 0)
+ tcp_ca_event(tp, CA_EVENT_TX_START);
th = (struct tcphdr *) skb_push(skb, tcp_header_size);
skb->h.th = th;
@@ -521,6 +515,7 @@ static int tcp_fragment(struct sock *sk, struct sk_buff *skb, u32 len)
* skbs, which it never sent before. --ANK
*/
TCP_SKB_CB(buff)->when = TCP_SKB_CB(skb)->when;
+ buff->stamp = skb->stamp;
if (TCP_SKB_CB(skb)->sacked & TCPCB_LOST) {
tp->lost_out -= tcp_skb_pcount(skb);
@@ -1449,7 +1444,6 @@ static inline void tcp_connect_init(struct sock *sk)
tp->window_clamp = dst_metric(dst, RTAX_WINDOW);
tp->advmss = dst_metric(dst, RTAX_ADVMSS);
tcp_initialize_rcv_mss(sk);
- tcp_ca_init(tp);
tcp_select_initial_window(tcp_full_space(sk),
tp->advmss - (tp->rx_opt.ts_recent_stamp ? tp->tcp_header_len - sizeof(struct tcphdr) : 0),
@@ -1503,7 +1497,6 @@ int tcp_connect(struct sock *sk)
TCP_SKB_CB(buff)->end_seq = tp->write_seq;
tp->snd_nxt = tp->write_seq;
tp->pushed_seq = tp->write_seq;
- tcp_ca_init(tp);
/* Send it off. */
TCP_SKB_CB(buff)->when = tcp_time_stamp;
diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c
index 2414937f2a83..fce56039b0e9 100644
--- a/net/ipv6/tcp_ipv6.c
+++ b/net/ipv6/tcp_ipv6.c
@@ -2025,7 +2025,7 @@ static int tcp_v6_init_sock(struct sock *sk)
sk->sk_state = TCP_CLOSE;
tp->af_specific = &ipv6_specific;
-
+ tp->ca_ops = &tcp_reno;
sk->sk_write_space = sk_stream_write_space;
sock_set_flag(sk, SOCK_USE_WRITE_QUEUE);