1 /* 2 * ip_vs_est.c: simple rate estimator for IPVS 3 * 4 * Authors: Wensong Zhang <wensong@linuxvirtualserver.org> 5 * 6 * This program is free software; you can redistribute it and/or 7 * modify it under the terms of the GNU General Public License 8 * as published by the Free Software Foundation; either version 9 * 2 of the License, or (at your option) any later version. 10 * 11 * Changes: 12 * 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/slab.h> 21 #include <linux/types.h> 22 #include <linux/interrupt.h> 23 #include <linux/sysctl.h> 24 #include <linux/list.h> 25 26 #include <net/ip_vs.h> 27 28 /* 29 This code is to estimate rate in a shorter interval (such as 8 30 seconds) for virtual services and real servers. For measure rate in a 31 long interval, it is easy to implement a user level daemon which 32 periodically reads those statistical counters and measure rate. 33 34 Currently, the measurement is activated by slow timer handler. Hope 35 this measurement will not introduce too much load. 36 37 We measure rate during the last 8 seconds every 2 seconds: 38 39 avgrate = avgrate*(1-W) + rate*W 40 41 where W = 2^(-2) 42 43 NOTES. 44 45 * The stored value for average bps is scaled by 2^5, so that maximal 46 rate is ~2.15Gbits/s, average pps and cps are scaled by 2^10. 47 48 * A lot code is taken from net/sched/estimator.c 49 */ 50 51 52 static void estimation_timer(unsigned long arg); 53 54 static LIST_HEAD(est_list); 55 static DEFINE_SPINLOCK(est_lock); 56 static DEFINE_TIMER(est_timer, estimation_timer, 0, 0); 57 58 static void estimation_timer(unsigned long arg) 59 { 60 struct ip_vs_estimator *e; 61 struct ip_vs_stats *s; 62 u32 n_conns; 63 u32 n_inpkts, n_outpkts; 64 u64 n_inbytes, n_outbytes; 65 u32 rate; 66 67 spin_lock(&est_lock); 68 list_for_each_entry(e, &est_list, list) { 69 s = container_of(e, struct ip_vs_stats, est); 70 71 spin_lock(&s->lock); 72 n_conns = s->ustats.conns; 73 n_inpkts = s->ustats.inpkts; 74 n_outpkts = s->ustats.outpkts; 75 n_inbytes = s->ustats.inbytes; 76 n_outbytes = s->ustats.outbytes; 77 78 /* scaled by 2^10, but divided 2 seconds */ 79 rate = (n_conns - e->last_conns)<<9; 80 e->last_conns = n_conns; 81 e->cps += ((long)rate - (long)e->cps)>>2; 82 s->ustats.cps = (e->cps+0x1FF)>>10; 83 84 rate = (n_inpkts - e->last_inpkts)<<9; 85 e->last_inpkts = n_inpkts; 86 e->inpps += ((long)rate - (long)e->inpps)>>2; 87 s->ustats.inpps = (e->inpps+0x1FF)>>10; 88 89 rate = (n_outpkts - e->last_outpkts)<<9; 90 e->last_outpkts = n_outpkts; 91 e->outpps += ((long)rate - (long)e->outpps)>>2; 92 s->ustats.outpps = (e->outpps+0x1FF)>>10; 93 94 rate = (n_inbytes - e->last_inbytes)<<4; 95 e->last_inbytes = n_inbytes; 96 e->inbps += ((long)rate - (long)e->inbps)>>2; 97 s->ustats.inbps = (e->inbps+0xF)>>5; 98 99 rate = (n_outbytes - e->last_outbytes)<<4; 100 e->last_outbytes = n_outbytes; 101 e->outbps += ((long)rate - (long)e->outbps)>>2; 102 s->ustats.outbps = (e->outbps+0xF)>>5; 103 spin_unlock(&s->lock); 104 } 105 spin_unlock(&est_lock); 106 mod_timer(&est_timer, jiffies + 2*HZ); 107 } 108 109 void ip_vs_new_estimator(struct ip_vs_stats *stats) 110 { 111 struct ip_vs_estimator *est = &stats->est; 112 113 INIT_LIST_HEAD(&est->list); 114 115 est->last_conns = stats->ustats.conns; 116 est->cps = stats->ustats.cps<<10; 117 118 est->last_inpkts = stats->ustats.inpkts; 119 est->inpps = stats->ustats.inpps<<10; 120 121 est->last_outpkts = stats->ustats.outpkts; 122 est->outpps = stats->ustats.outpps<<10; 123 124 est->last_inbytes = stats->ustats.inbytes; 125 est->inbps = stats->ustats.inbps<<5; 126 127 est->last_outbytes = stats->ustats.outbytes; 128 est->outbps = stats->ustats.outbps<<5; 129 130 spin_lock_bh(&est_lock); 131 list_add(&est->list, &est_list); 132 spin_unlock_bh(&est_lock); 133 } 134 135 void ip_vs_kill_estimator(struct ip_vs_stats *stats) 136 { 137 struct ip_vs_estimator *est = &stats->est; 138 139 spin_lock_bh(&est_lock); 140 list_del(&est->list); 141 spin_unlock_bh(&est_lock); 142 } 143 144 void ip_vs_zero_estimator(struct ip_vs_stats *stats) 145 { 146 struct ip_vs_estimator *est = &stats->est; 147 148 /* set counters zero, caller must hold the stats->lock lock */ 149 est->last_inbytes = 0; 150 est->last_outbytes = 0; 151 est->last_conns = 0; 152 est->last_inpkts = 0; 153 est->last_outpkts = 0; 154 est->cps = 0; 155 est->inpps = 0; 156 est->outpps = 0; 157 est->inbps = 0; 158 est->outbps = 0; 159 } 160 161 int __init ip_vs_estimator_init(void) 162 { 163 mod_timer(&est_timer, jiffies + 2 * HZ); 164 return 0; 165 } 166 167 void ip_vs_estimator_cleanup(void) 168 { 169 del_timer_sync(&est_timer); 170 } 171