1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * ip_vs_est.c: simple rate estimator for IPVS 4 * 5 * Authors: Wensong Zhang <wensong@linuxvirtualserver.org> 6 * 7 * Changes: Hans Schillstrom <hans.schillstrom@ericsson.com> 8 * Network name space (netns) aware. 9 * Global data moved to netns i.e struct netns_ipvs 10 * Affected data: est_list and est_lock. 11 * estimation_timer() runs with timer per netns. 12 * get_stats()) do the per cpu summing. 13 */ 14 15 #define KMSG_COMPONENT "IPVS" 16 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt 17 18 #include <linux/kernel.h> 19 #include <linux/jiffies.h> 20 #include <linux/types.h> 21 #include <linux/interrupt.h> 22 #include <linux/sysctl.h> 23 #include <linux/list.h> 24 25 #include <net/ip_vs.h> 26 27 /* 28 This code is to estimate rate in a shorter interval (such as 8 29 seconds) for virtual services and real servers. For measure rate in a 30 long interval, it is easy to implement a user level daemon which 31 periodically reads those statistical counters and measure rate. 32 33 Currently, the measurement is activated by slow timer handler. Hope 34 this measurement will not introduce too much load. 35 36 We measure rate during the last 8 seconds every 2 seconds: 37 38 avgrate = avgrate*(1-W) + rate*W 39 40 where W = 2^(-2) 41 42 NOTES. 43 44 * Average bps is scaled by 2^5, while average pps and cps are scaled by 2^10. 45 46 * Netlink users can see 64-bit values but sockopt users are restricted 47 to 32-bit values for conns, packets, bps, cps and pps. 48 49 * A lot of code is taken from net/core/gen_estimator.c 50 */ 51 52 53 /* 54 * Make a summary from each cpu 55 */ 56 static void ip_vs_read_cpu_stats(struct ip_vs_kstats *sum, 57 struct ip_vs_cpu_stats __percpu *stats) 58 { 59 int i; 60 bool add = false; 61 62 for_each_possible_cpu(i) { 63 struct ip_vs_cpu_stats *s = per_cpu_ptr(stats, i); 64 unsigned int start; 65 u64 conns, inpkts, outpkts, inbytes, outbytes; 66 67 if (add) { 68 do { 69 start = u64_stats_fetch_begin(&s->syncp); 70 conns = s->cnt.conns; 71 inpkts = s->cnt.inpkts; 72 outpkts = s->cnt.outpkts; 73 inbytes = s->cnt.inbytes; 74 outbytes = s->cnt.outbytes; 75 } while (u64_stats_fetch_retry(&s->syncp, start)); 76 sum->conns += conns; 77 sum->inpkts += inpkts; 78 sum->outpkts += outpkts; 79 sum->inbytes += inbytes; 80 sum->outbytes += outbytes; 81 } else { 82 add = true; 83 do { 84 start = u64_stats_fetch_begin(&s->syncp); 85 sum->conns = s->cnt.conns; 86 sum->inpkts = s->cnt.inpkts; 87 sum->outpkts = s->cnt.outpkts; 88 sum->inbytes = s->cnt.inbytes; 89 sum->outbytes = s->cnt.outbytes; 90 } while (u64_stats_fetch_retry(&s->syncp, start)); 91 } 92 } 93 } 94 95 96 static void estimation_timer(struct timer_list *t) 97 { 98 struct ip_vs_estimator *e; 99 struct ip_vs_stats *s; 100 u64 rate; 101 struct netns_ipvs *ipvs = from_timer(ipvs, t, est_timer); 102 103 spin_lock(&ipvs->est_lock); 104 list_for_each_entry(e, &ipvs->est_list, list) { 105 s = container_of(e, struct ip_vs_stats, est); 106 107 spin_lock(&s->lock); 108 ip_vs_read_cpu_stats(&s->kstats, s->cpustats); 109 110 /* scaled by 2^10, but divided 2 seconds */ 111 rate = (s->kstats.conns - e->last_conns) << 9; 112 e->last_conns = s->kstats.conns; 113 e->cps += ((s64)rate - (s64)e->cps) >> 2; 114 115 rate = (s->kstats.inpkts - e->last_inpkts) << 9; 116 e->last_inpkts = s->kstats.inpkts; 117 e->inpps += ((s64)rate - (s64)e->inpps) >> 2; 118 119 rate = (s->kstats.outpkts - e->last_outpkts) << 9; 120 e->last_outpkts = s->kstats.outpkts; 121 e->outpps += ((s64)rate - (s64)e->outpps) >> 2; 122 123 /* scaled by 2^5, but divided 2 seconds */ 124 rate = (s->kstats.inbytes - e->last_inbytes) << 4; 125 e->last_inbytes = s->kstats.inbytes; 126 e->inbps += ((s64)rate - (s64)e->inbps) >> 2; 127 128 rate = (s->kstats.outbytes - e->last_outbytes) << 4; 129 e->last_outbytes = s->kstats.outbytes; 130 e->outbps += ((s64)rate - (s64)e->outbps) >> 2; 131 spin_unlock(&s->lock); 132 } 133 spin_unlock(&ipvs->est_lock); 134 mod_timer(&ipvs->est_timer, jiffies + 2*HZ); 135 } 136 137 void ip_vs_start_estimator(struct netns_ipvs *ipvs, struct ip_vs_stats *stats) 138 { 139 struct ip_vs_estimator *est = &stats->est; 140 141 INIT_LIST_HEAD(&est->list); 142 143 spin_lock_bh(&ipvs->est_lock); 144 list_add(&est->list, &ipvs->est_list); 145 spin_unlock_bh(&ipvs->est_lock); 146 } 147 148 void ip_vs_stop_estimator(struct netns_ipvs *ipvs, struct ip_vs_stats *stats) 149 { 150 struct ip_vs_estimator *est = &stats->est; 151 152 spin_lock_bh(&ipvs->est_lock); 153 list_del(&est->list); 154 spin_unlock_bh(&ipvs->est_lock); 155 } 156 157 void ip_vs_zero_estimator(struct ip_vs_stats *stats) 158 { 159 struct ip_vs_estimator *est = &stats->est; 160 struct ip_vs_kstats *k = &stats->kstats; 161 162 /* reset counters, caller must hold the stats->lock lock */ 163 est->last_inbytes = k->inbytes; 164 est->last_outbytes = k->outbytes; 165 est->last_conns = k->conns; 166 est->last_inpkts = k->inpkts; 167 est->last_outpkts = k->outpkts; 168 est->cps = 0; 169 est->inpps = 0; 170 est->outpps = 0; 171 est->inbps = 0; 172 est->outbps = 0; 173 } 174 175 /* Get decoded rates */ 176 void ip_vs_read_estimator(struct ip_vs_kstats *dst, struct ip_vs_stats *stats) 177 { 178 struct ip_vs_estimator *e = &stats->est; 179 180 dst->cps = (e->cps + 0x1FF) >> 10; 181 dst->inpps = (e->inpps + 0x1FF) >> 10; 182 dst->outpps = (e->outpps + 0x1FF) >> 10; 183 dst->inbps = (e->inbps + 0xF) >> 5; 184 dst->outbps = (e->outbps + 0xF) >> 5; 185 } 186 187 int __net_init ip_vs_estimator_net_init(struct netns_ipvs *ipvs) 188 { 189 INIT_LIST_HEAD(&ipvs->est_list); 190 spin_lock_init(&ipvs->est_lock); 191 timer_setup(&ipvs->est_timer, estimation_timer, 0); 192 mod_timer(&ipvs->est_timer, jiffies + 2 * HZ); 193 return 0; 194 } 195 196 void __net_exit ip_vs_estimator_net_cleanup(struct netns_ipvs *ipvs) 197 { 198 del_timer_sync(&ipvs->est_timer); 199 } 200