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Diffstat (limited to 'net/ipv4/tcp_htcp.c')
-rw-r--r--net/ipv4/tcp_htcp.c67
1 files changed, 38 insertions, 29 deletions
diff --git a/net/ipv4/tcp_htcp.c b/net/ipv4/tcp_htcp.c
index 753987a1048..1020eb48d8d 100644
--- a/net/ipv4/tcp_htcp.c
+++ b/net/ipv4/tcp_htcp.c
@@ -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);
}
@@ -224,10 +234,9 @@ static void htcp_cong_avoid(struct sock *sk, u32 ack, u32 rtt,
if (!tcp_is_cwnd_limited(sk, in_flight))
return;
- if (tp->snd_cwnd <= tp->snd_ssthresh)
+ if (tp->snd_cwnd <= tp->snd_ssthresh)
tcp_slow_start(tp);
else {
-
measure_rtt(sk);
/* In dangerous area, increase slowly.
generated by cgit v1.2.3-70-g09d2 (git 2.46.0) at 2024-12-15 00:05:46 +0000