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Commit 317a76f9 authored by Stephen Hemminger's avatar Stephen Hemminger Committed by David S. Miller
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[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: default avatarStephen Hemminger <shemminger@osdl.org>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent a8ad86f2
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Showing with 399 additions and 999 deletions
include/linux/sysctl.h
View file @ 317a76f9
......@@ -333,21 +333,14 @@ enum
NET_TCP_FRTO=92,
NET_TCP_LOW_LATENCY=93,
NET_IPV4_IPFRAG_SECRET_INTERVAL=94,
NET_TCP_WESTWOOD=95,
NET_IPV4_IGMP_MAX_MSF=96,
NET_TCP_NO_METRICS_SAVE=97,
NET_TCP_VEGAS=98,
NET_TCP_VEGAS_ALPHA=99,
NET_TCP_VEGAS_BETA=100,
NET_TCP_VEGAS_GAMMA=101,
NET_TCP_BIC=102,
NET_TCP_BIC_FAST_CONVERGENCE=103,
NET_TCP_BIC_LOW_WINDOW=104,
NET_TCP_DEFAULT_WIN_SCALE=105,
NET_TCP_MODERATE_RCVBUF=106,
NET_TCP_TSO_WIN_DIVISOR=107,
NET_TCP_BIC_BETA=108,
NET_IPV4_ICMP_ERRORS_USE_INBOUND_IFADDR=109,
NET_TCP_CONG_CONTROL=110,
};
enum {
......
include/linux/tcp.h
View file @ 317a76f9
......@@ -203,13 +203,6 @@ struct tcp_sack_block {
__u32 end_seq;
};
enum tcp_congestion_algo {
TCP_RENO=0,
TCP_VEGAS,
TCP_WESTWOOD,
TCP_BIC,
};
struct tcp_options_received {
/* PAWS/RTTM data */
long ts_recent_stamp;/* Time we stored ts_recent (for aging) */
......@@ -305,7 +298,7 @@ struct tcp_sock {
__u8 reordering; /* Packet reordering metric. */
__u8 frto_counter; /* Number of new acks after RTO */
__u8 adv_cong; /* Using Vegas, Westwood, or BIC */
__u8 unused;
__u8 defer_accept; /* User waits for some data after accept() */
/* RTT measurement */
......@@ -401,37 +394,10 @@ struct tcp_sock {
__u32 time;
} rcvq_space;
/* TCP Westwood structure */
struct {
__u32 bw_ns_est; /* first bandwidth estimation..not too smoothed 8) */
__u32 bw_est; /* bandwidth estimate */
__u32 rtt_win_sx; /* here starts a new evaluation... */
__u32 bk;
__u32 snd_una; /* used for evaluating the number of acked bytes */
__u32 cumul_ack;
__u32 accounted;
__u32 rtt;
__u32 rtt_min; /* minimum observed RTT */
} westwood;
/* Vegas variables */
struct {
__u32 beg_snd_nxt; /* right edge during last RTT */
__u32 beg_snd_una; /* left edge during last RTT */
__u32 beg_snd_cwnd; /* saves the size of the cwnd */
__u8 doing_vegas_now;/* if true, do vegas for this RTT */
__u16 cntRTT; /* # of RTTs measured within last RTT */
__u32 minRTT; /* min of RTTs measured within last RTT (in usec) */
__u32 baseRTT; /* the min of all Vegas RTT measurements seen (in usec) */
} vegas;
/* BI TCP Parameters */
struct {
__u32 cnt; /* increase cwnd by 1 after this number of ACKs */
__u32 last_max_cwnd; /* last maximium snd_cwnd */
__u32 last_cwnd; /* the last snd_cwnd */
__u32 last_stamp; /* time when updated last_cwnd */
} bictcp;
/* Pluggable TCP congestion control hook */
struct tcp_congestion_ops *ca_ops;
u32 ca_priv[16];
#define TCP_CA_PRIV_SIZE (16*sizeof(u32))
};
static inline struct tcp_sock *tcp_sk(const struct sock *sk)
......@@ -439,6 +405,11 @@ static inline struct tcp_sock *tcp_sk(const struct sock *sk)
return (struct tcp_sock *)sk;
}
static inline void *tcp_ca(const struct tcp_sock *tp)
{
return (void *) tp->ca_priv;
}
#endif
#endif /* _LINUX_TCP_H */
include/net/tcp.h
View file @ 317a76f9
......@@ -505,25 +505,6 @@ static __inline__ int tcp_sk_listen_hashfn(struct sock *sk)
#else
# define TCP_TW_RECYCLE_TICK (12+2-TCP_TW_RECYCLE_SLOTS_LOG)
#endif
#define BICTCP_BETA_SCALE 1024 /* Scale factor beta calculation
* max_cwnd = snd_cwnd * beta
*/
#define BICTCP_MAX_INCREMENT 32 /*
* Limit on the amount of
* increment allowed during
* binary search.
*/
#define BICTCP_FUNC_OF_MIN_INCR 11 /*
* log(B/Smin)/log(B/(B-1))+1,
* Smin:min increment
* B:log factor
*/
#define BICTCP_B 4 /*
* In binary search,
* go to point (max+min)/N
*/
/*
* TCP option
*/
......@@ -596,16 +577,7 @@ extern int sysctl_tcp_adv_win_scale;
extern int sysctl_tcp_tw_reuse;
extern int sysctl_tcp_frto;
extern int sysctl_tcp_low_latency;
extern int sysctl_tcp_westwood;
extern int sysctl_tcp_vegas_cong_avoid;
extern int sysctl_tcp_vegas_alpha;
extern int sysctl_tcp_vegas_beta;
extern int sysctl_tcp_vegas_gamma;
extern int sysctl_tcp_nometrics_save;
extern int sysctl_tcp_bic;
extern int sysctl_tcp_bic_fast_convergence;
extern int sysctl_tcp_bic_low_window;
extern int sysctl_tcp_bic_beta;
extern int sysctl_tcp_moderate_rcvbuf;
extern int sysctl_tcp_tso_win_divisor;
......@@ -1136,6 +1108,80 @@ static inline void tcp_packets_out_dec(struct tcp_sock *tp,
tp->packets_out -= tcp_skb_pcount(skb);
}
/* Events passed to congestion control interface */
enum tcp_ca_event {
CA_EVENT_TX_START, /* first transmit when no packets in flight */
CA_EVENT_CWND_RESTART, /* congestion window restart */
CA_EVENT_COMPLETE_CWR, /* end of congestion recovery */
CA_EVENT_FRTO, /* fast recovery timeout */
CA_EVENT_LOSS, /* loss timeout */
CA_EVENT_FAST_ACK, /* in sequence ack */
CA_EVENT_SLOW_ACK, /* other ack */
};
/*
* Interface for adding new TCP congestion control handlers
*/
#define TCP_CA_NAME_MAX 16
struct tcp_congestion_ops {
struct list_head list;
/* initialize private data (optional) */
void (*init)(struct tcp_sock *tp);
/* cleanup private data (optional) */
void (*release)(struct tcp_sock *tp);
/* return slow start threshold (required) */
u32 (*ssthresh)(struct tcp_sock *tp);
/* lower bound for congestion window (optional) */
u32 (*min_cwnd)(struct tcp_sock *tp);
/* do new cwnd calculation (required) */
void (*cong_avoid)(struct tcp_sock *tp, u32 ack,
u32 rtt, u32 in_flight, int good_ack);
/* round trip time sample per acked packet (optional) */
void (*rtt_sample)(struct tcp_sock *tp, u32 usrtt);
/* call before changing ca_state (optional) */
void (*set_state)(struct tcp_sock *tp, u8 new_state);
/* call when cwnd event occurs (optional) */
void (*cwnd_event)(struct tcp_sock *tp, enum tcp_ca_event ev);
/* new value of cwnd after loss (optional) */
u32 (*undo_cwnd)(struct tcp_sock *tp);
/* hook for packet ack accounting (optional) */
void (*pkts_acked)(struct tcp_sock *tp, u32 num_acked);
/* get info for tcp_diag (optional) */
void (*get_info)(struct tcp_sock *tp, u32 ext, struct sk_buff *skb);
char name[TCP_CA_NAME_MAX];
struct module *owner;
};
extern int tcp_register_congestion_control(struct tcp_congestion_ops *type);
extern void tcp_unregister_congestion_control(struct tcp_congestion_ops *type);
extern void tcp_init_congestion_control(struct tcp_sock *tp);
extern void tcp_cleanup_congestion_control(struct tcp_sock *tp);
extern int tcp_set_default_congestion_control(const char *name);
extern void tcp_get_default_congestion_control(char *name);
extern struct tcp_congestion_ops tcp_reno;
extern u32 tcp_reno_ssthresh(struct tcp_sock *tp);
extern void tcp_reno_cong_avoid(struct tcp_sock *tp, u32 ack,
u32 rtt, u32 in_flight, int flag);
extern u32 tcp_reno_min_cwnd(struct tcp_sock *tp);
static inline void tcp_set_ca_state(struct tcp_sock *tp, u8 ca_state)
{
if (tp->ca_ops->set_state)
tp->ca_ops->set_state(tp, ca_state);
tp->ca_state = ca_state;
}
static inline void tcp_ca_event(struct tcp_sock *tp, enum tcp_ca_event event)
{
if (tp->ca_ops->cwnd_event)
tp->ca_ops->cwnd_event(tp, event);
}
/* This determines how many packets are "in the network" to the best
* of our knowledge. In many cases it is conservative, but where
* detailed information is available from the receiver (via SACK
......@@ -1155,91 +1201,6 @@ static __inline__ unsigned int tcp_packets_in_flight(const struct tcp_sock *tp)
return (tp->packets_out - tp->left_out + tp->retrans_out);
}
/*
* Which congestion algorithim is in use on the connection.
*/
#define tcp_is_vegas(__tp) ((__tp)->adv_cong == TCP_VEGAS)
#define tcp_is_westwood(__tp) ((__tp)->adv_cong == TCP_WESTWOOD)
#define tcp_is_bic(__tp) ((__tp)->adv_cong == TCP_BIC)
/* Recalculate snd_ssthresh, we want to set it to:
*
* Reno:
* one half the current congestion window, but no
* less than two segments
*
* BIC:
* behave like Reno until low_window is reached,
* then increase congestion window slowly
*/
static inline __u32 tcp_recalc_ssthresh(struct tcp_sock *tp)
{
if (tcp_is_bic(tp)) {
if (sysctl_tcp_bic_fast_convergence &&
tp->snd_cwnd < tp->bictcp.last_max_cwnd)
tp->bictcp.last_max_cwnd = (tp->snd_cwnd *
(BICTCP_BETA_SCALE
+ sysctl_tcp_bic_beta))
/ (2 * BICTCP_BETA_SCALE);
else
tp->bictcp.last_max_cwnd = tp->snd_cwnd;
if (tp->snd_cwnd > sysctl_tcp_bic_low_window)
return max((tp->snd_cwnd * sysctl_tcp_bic_beta)
/ BICTCP_BETA_SCALE, 2U);
}
return max(tp->snd_cwnd >> 1U, 2U);
}
/* Stop taking Vegas samples for now. */
#define tcp_vegas_disable(__tp) ((__tp)->vegas.doing_vegas_now = 0)
static inline void tcp_vegas_enable(struct tcp_sock *tp)
{
/* There are several situations when we must "re-start" Vegas:
*
* o when a connection is established
* o after an RTO
* o after fast recovery
* o when we send a packet and there is no outstanding
* unacknowledged data (restarting an idle connection)
*
* In these circumstances we cannot do a Vegas calculation at the
* end of the first RTT, because any calculation we do is using
* stale info -- both the saved cwnd and congestion feedback are
* stale.
*
* Instead we must wait until the completion of an RTT during
* which we actually receive ACKs.
*/
/* Begin taking Vegas samples next time we send something. */
tp->vegas.doing_vegas_now = 1;
/* Set the beginning of the next send window. */
tp->vegas.beg_snd_nxt = tp->snd_nxt;
tp->vegas.cntRTT = 0;
tp->vegas.minRTT = 0x7fffffff;
}
/* Should we be taking Vegas samples right now? */
#define tcp_vegas_enabled(__tp) ((__tp)->vegas.doing_vegas_now)
extern void tcp_ca_init(struct tcp_sock *tp);
static inline void tcp_set_ca_state(struct tcp_sock *tp, u8 ca_state)
{
if (tcp_is_vegas(tp)) {
if (ca_state == TCP_CA_Open)
tcp_vegas_enable(tp);
else
tcp_vegas_disable(tp);
}
tp->ca_state = ca_state;
}
/* If cwnd > ssthresh, we may raise ssthresh to be half-way to cwnd.
* The exception is rate halving phase, when cwnd is decreasing towards
* ssthresh.
......@@ -1288,7 +1249,7 @@ static inline void tcp_cwnd_validate(struct sock *sk, struct tcp_sock *tp)
static inline void __tcp_enter_cwr(struct tcp_sock *tp)
{
tp->undo_marker = 0;
tp->snd_ssthresh = tcp_recalc_ssthresh(tp);
tp->snd_ssthresh = tp->ca_ops->ssthresh(tp);
tp->snd_cwnd = min(tp->snd_cwnd,
tcp_packets_in_flight(tp) + 1U);
tp->snd_cwnd_cnt = 0;
......@@ -1876,52 +1837,4 @@ struct tcp_iter_state {
extern int tcp_proc_register(struct tcp_seq_afinfo *afinfo);
extern void tcp_proc_unregister(struct tcp_seq_afinfo *afinfo);
/* TCP Westwood functions and constants */
#define TCP_WESTWOOD_INIT_RTT (20*HZ) /* maybe too conservative?! */
#define TCP_WESTWOOD_RTT_MIN (HZ/20) /* 50ms */
static inline void tcp_westwood_update_rtt(struct tcp_sock *tp, __u32 rtt_seq)
{
if (tcp_is_westwood(tp))
tp->westwood.rtt = rtt_seq;
}
static inline __u32 __tcp_westwood_bw_rttmin(const struct tcp_sock *tp)
{
return max((tp->westwood.bw_est) * (tp->westwood.rtt_min) /
(__u32) (tp->mss_cache_std),
2U);
}
static inline __u32 tcp_westwood_bw_rttmin(const struct tcp_sock *tp)
{
return tcp_is_westwood(tp) ? __tcp_westwood_bw_rttmin(tp) : 0;
}
static inline int tcp_westwood_ssthresh(struct tcp_sock *tp)
{
__u32 ssthresh = 0;
if (tcp_is_westwood(tp)) {
ssthresh = __tcp_westwood_bw_rttmin(tp);
if (ssthresh)
tp->snd_ssthresh = ssthresh;
}
return (ssthresh != 0);
}
static inline int tcp_westwood_cwnd(struct tcp_sock *tp)
{
__u32 cwnd = 0;
if (tcp_is_westwood(tp)) {
cwnd = __tcp_westwood_bw_rttmin(tp);
if (cwnd)
tp->snd_cwnd = cwnd;
}
return (cwnd != 0);
}
#endif /* _TCP_H */
net/ipv4/Makefile
View file @ 317a76f9
......@@ -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
......
net/ipv4/sysctl_net_ipv4.c
View file @ 317a76f9
......@@ -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,
......@@ -611,70 +650,6 @@ ctl_table ipv4_table[] = {
.mode = 0644,
.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",
......@@ -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 }
};
......
net/ipv4/tcp.c
View file @ 317a76f9
......@@ -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);
......
net/ipv4/tcp_cong.c 0 → 100644
View file @ 317a76f9
/*
* 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);
net/ipv4/tcp_diag.c
View file @ 317a76f9
......@@ -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;
......
net/ipv4/tcp_input.c
View file @ 317a76f9
This diff is collapsed.
net/ipv4/tcp_ipv4.c
View file @ 317a76f9
......@@ -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);
......
net/ipv4/tcp_minisocks.c
View file @ 317a76f9
......@@ -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;
......
net/ipv4/tcp_output.c
View file @ 317a76f9
......@@ -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;
......
net/ipv6/tcp_ipv6.c
View file @ 317a76f9
......@@ -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);
......
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