[TCP]: cleanup of htcp (resend)
Minor non-invasive cleanups: * white space around operators and line wrapping * use const * use __read_mostly Signed-off-by: Stephen Hemminger <shemminger@linux-foundation.org> Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Stephen Hemminger
David S. Miller
parent
59758f4459
commit
9121c77706
|
|
@ -10,22 +10,23 @@
|
|||
#include <linux/module.h>
|
||||
#include <net/tcp.h>
|
||||
|
||||
#define ALPHA_BASE (1<<7) /* 1.0 with shift << 7 */
|
||||
#define BETA_MIN (1<<6) /* 0.5 with shift << 7 */
|
||||
#define ALPHA_BASE (1<<7) /* 1.0 with shift << 7 */
|
||||
#define BETA_MIN (1<<6) /* 0.5 with shift << 7 */
|
||||
#define BETA_MAX 102 /* 0.8 with shift << 7 */
|
||||
|
||||
static int use_rtt_scaling = 1;
|
||||
static int use_rtt_scaling __read_mostly = 1;
|
||||
module_param(use_rtt_scaling, int, 0644);
|
||||
MODULE_PARM_DESC(use_rtt_scaling, "turn on/off RTT scaling");
|
||||
|
||||
static int use_bandwidth_switch = 1;
|
||||
static int use_bandwidth_switch __read_mostly = 1;
|
||||
module_param(use_bandwidth_switch, int, 0644);
|
||||
MODULE_PARM_DESC(use_bandwidth_switch, "turn on/off bandwidth switcher");
|
||||
|
||||
struct htcp {
|
||||
u32 alpha; /* Fixed point arith, << 7 */
|
||||
u8 beta; /* Fixed point arith, << 7 */
|
||||
u8 modeswitch; /* Delay modeswitch until we had at least one congestion event */
|
||||
u8 modeswitch; /* Delay modeswitch
|
||||
until we had at least one congestion event */
|
||||
u16 pkts_acked;
|
||||
u32 packetcount;
|
||||
u32 minRTT;
|
||||
|
|
@ -44,14 +45,14 @@ struct htcp {
|
|||
u32 lasttime;
|
||||
};
|
||||
|
||||
static inline u32 htcp_cong_time(struct htcp *ca)
|
||||
static inline u32 htcp_cong_time(const struct htcp *ca)
|
||||
{
|
||||
return jiffies - ca->last_cong;
|
||||
}
|
||||
|
||||
static inline u32 htcp_ccount(struct htcp *ca)
|
||||
static inline u32 htcp_ccount(const struct htcp *ca)
|
||||
{
|
||||
return htcp_cong_time(ca)/ca->minRTT;
|
||||
return htcp_cong_time(ca) / ca->minRTT;
|
||||
}
|
||||
|
||||
static inline void htcp_reset(struct htcp *ca)
|
||||
|
|
@ -67,10 +68,12 @@ static u32 htcp_cwnd_undo(struct sock *sk)
|
|||
{
|
||||
const struct tcp_sock *tp = tcp_sk(sk);
|
||||
struct htcp *ca = inet_csk_ca(sk);
|
||||
|
||||
ca->last_cong = ca->undo_last_cong;
|
||||
ca->maxRTT = ca->undo_maxRTT;
|
||||
ca->old_maxB = ca->undo_old_maxB;
|
||||
return max(tp->snd_cwnd, (tp->snd_ssthresh<<7)/ca->beta);
|
||||
|
||||
return max(tp->snd_cwnd, (tp->snd_ssthresh << 7) / ca->beta);
|
||||
}
|
||||
|
||||
static inline void measure_rtt(struct sock *sk)
|
||||
|
|
@ -78,17 +81,19 @@ static inline void measure_rtt(struct sock *sk)
|
|||
const struct inet_connection_sock *icsk = inet_csk(sk);
|
||||
const struct tcp_sock *tp = tcp_sk(sk);
|
||||
struct htcp *ca = inet_csk_ca(sk);
|
||||
u32 srtt = tp->srtt>>3;
|
||||
u32 srtt = tp->srtt >> 3;
|
||||
|
||||
/* keep track of minimum RTT seen so far, minRTT is zero at first */
|
||||
if (ca->minRTT > srtt || !ca->minRTT)
|
||||
ca->minRTT = srtt;
|
||||
|
||||
/* max RTT */
|
||||
if (icsk->icsk_ca_state == TCP_CA_Open && tp->snd_ssthresh < 0xFFFF && htcp_ccount(ca) > 3) {
|
||||
if (icsk->icsk_ca_state == TCP_CA_Open
|
||||
&& tp->snd_ssthresh < 0xFFFF && htcp_ccount(ca) > 3) {
|
||||
if (ca->maxRTT < ca->minRTT)
|
||||
ca->maxRTT = ca->minRTT;
|
||||
if (ca->maxRTT < srtt && srtt <= ca->maxRTT+msecs_to_jiffies(20))
|
||||
if (ca->maxRTT < srtt
|
||||
&& srtt <= ca->maxRTT + msecs_to_jiffies(20))
|
||||
ca->maxRTT = srtt;
|
||||
}
|
||||
}
|
||||
|
|
@ -116,15 +121,16 @@ static void measure_achieved_throughput(struct sock *sk, u32 pkts_acked)
|
|||
|
||||
ca->packetcount += pkts_acked;
|
||||
|
||||
if (ca->packetcount >= tp->snd_cwnd - (ca->alpha>>7? : 1)
|
||||
&& now - ca->lasttime >= ca->minRTT
|
||||
&& ca->minRTT > 0) {
|
||||
__u32 cur_Bi = ca->packetcount*HZ/(now - ca->lasttime);
|
||||
if (ca->packetcount >= tp->snd_cwnd - (ca->alpha >> 7 ? : 1)
|
||||
&& now - ca->lasttime >= ca->minRTT
|
||||
&& ca->minRTT > 0) {
|
||||
__u32 cur_Bi = ca->packetcount * HZ / (now - ca->lasttime);
|
||||
|
||||
if (htcp_ccount(ca) <= 3) {
|
||||
/* just after backoff */
|
||||
ca->minB = ca->maxB = ca->Bi = cur_Bi;
|
||||
} else {
|
||||
ca->Bi = (3*ca->Bi + cur_Bi)/4;
|
||||
ca->Bi = (3 * ca->Bi + cur_Bi) / 4;
|
||||
if (ca->Bi > ca->maxB)
|
||||
ca->maxB = ca->Bi;
|
||||
if (ca->minB > ca->maxB)
|
||||
|
|
@ -142,7 +148,7 @@ static inline void htcp_beta_update(struct htcp *ca, u32 minRTT, u32 maxRTT)
|
|||
u32 old_maxB = ca->old_maxB;
|
||||
ca->old_maxB = ca->maxB;
|
||||
|
||||
if (!between(5*maxB, 4*old_maxB, 6*old_maxB)) {
|
||||
if (!between(5 * maxB, 4 * old_maxB, 6 * old_maxB)) {
|
||||
ca->beta = BETA_MIN;
|
||||
ca->modeswitch = 0;
|
||||
return;
|
||||
|
|
@ -150,7 +156,7 @@ static inline void htcp_beta_update(struct htcp *ca, u32 minRTT, u32 maxRTT)
|
|||
}
|
||||
|
||||
if (ca->modeswitch && minRTT > msecs_to_jiffies(10) && maxRTT) {
|
||||
ca->beta = (minRTT<<7)/maxRTT;
|
||||
ca->beta = (minRTT << 7) / maxRTT;
|
||||
if (ca->beta < BETA_MIN)
|
||||
ca->beta = BETA_MIN;
|
||||
else if (ca->beta > BETA_MAX)
|
||||
|
|
@ -169,23 +175,26 @@ static inline void htcp_alpha_update(struct htcp *ca)
|
|||
|
||||
if (diff > HZ) {
|
||||
diff -= HZ;
|
||||
factor = 1+ ( 10*diff + ((diff/2)*(diff/2)/HZ) )/HZ;
|
||||
factor = 1 + (10 * diff + ((diff / 2) * (diff / 2) / HZ)) / HZ;
|
||||
}
|
||||
|
||||
if (use_rtt_scaling && minRTT) {
|
||||
u32 scale = (HZ<<3)/(10*minRTT);
|
||||
scale = min(max(scale, 1U<<2), 10U<<3); /* clamping ratio to interval [0.5,10]<<3 */
|
||||
factor = (factor<<3)/scale;
|
||||
u32 scale = (HZ << 3) / (10 * minRTT);
|
||||
|
||||
/* clamping ratio to interval [0.5,10]<<3 */
|
||||
scale = min(max(scale, 1U << 2), 10U << 3);
|
||||
factor = (factor << 3) / scale;
|
||||
if (!factor)
|
||||
factor = 1;
|
||||
}
|
||||
|
||||
ca->alpha = 2*factor*((1<<7)-ca->beta);
|
||||
ca->alpha = 2 * factor * ((1 << 7) - ca->beta);
|
||||
if (!ca->alpha)
|
||||
ca->alpha = ALPHA_BASE;
|
||||
}
|
||||
|
||||
/* After we have the rtt data to calculate beta, we'd still prefer to wait one
|
||||
/*
|
||||
* After we have the rtt data to calculate beta, we'd still prefer to wait one
|
||||
* rtt before we adjust our beta to ensure we are working from a consistent
|
||||
* data.
|
||||
*
|
||||
|
|
@ -202,15 +211,16 @@ static void htcp_param_update(struct sock *sk)
|
|||
htcp_beta_update(ca, minRTT, maxRTT);
|
||||
htcp_alpha_update(ca);
|
||||
|
||||
/* add slowly fading memory for maxRTT to accommodate routing changes etc */
|
||||
/* add slowly fading memory for maxRTT to accommodate routing changes */
|
||||
if (minRTT > 0 && maxRTT > minRTT)
|
||||
ca->maxRTT = minRTT + ((maxRTT-minRTT)*95)/100;
|
||||
ca->maxRTT = minRTT + ((maxRTT - minRTT) * 95) / 100;
|
||||
}
|
||||
|
||||
static u32 htcp_recalc_ssthresh(struct sock *sk)
|
||||
{
|
||||
const struct tcp_sock *tp = tcp_sk(sk);
|
||||
const struct htcp *ca = inet_csk_ca(sk);
|
||||
|
||||
htcp_param_update(sk);
|
||||
return max((tp->snd_cwnd * ca->beta) >> 7, 2U);
|
||||
}
|
||||
|
|
@ -227,7 +237,6 @@ static void htcp_cong_avoid(struct sock *sk, u32 ack, u32 rtt,
|
|||
if (tp->snd_cwnd <= tp->snd_ssthresh)
|
||||
tcp_slow_start(tp);
|
||||
else {
|
||||
|
||||
measure_rtt(sk);
|
||||
|
||||
/* In dangerous area, increase slowly.
|
||||
|
|
|
|||
Loading…
Reference in New Issue