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 #include <linux/kernel.h> 15 #include <linux/jiffies.h> 16 #include <linux/slab.h> 17 #include <linux/types.h> 18 #include <linux/interrupt.h> 19 #include <linux/sysctl.h> 20 #include <linux/list.h> 21 22 #include <net/ip_vs.h> 23 24 /* 25 This code is to estimate rate in a shorter interval (such as 8 26 seconds) for virtual services and real servers. For measure rate in a 27 long interval, it is easy to implement a user level daemon which 28 periodically reads those statistical counters and measure rate. 29 30 Currently, the measurement is activated by slow timer handler. Hope 31 this measurement will not introduce too much load. 32 33 We measure rate during the last 8 seconds every 2 seconds: 34 35 avgrate = avgrate*(1-W) + rate*W 36 37 where W = 2^(-2) 38 39 NOTES. 40 41 * The stored value for average bps is scaled by 2^5, so that maximal 42 rate is ~2.15Gbits/s, average pps and cps are scaled by 2^10. 43 44 * A lot code is taken from net/sched/estimator.c 45 */ 46 47 48 static void estimation_timer(unsigned long arg); 49 50 static LIST_HEAD(est_list); 51 static DEFINE_SPINLOCK(est_lock); 52 static DEFINE_TIMER(est_timer, estimation_timer, 0, 0); 53 54 static void estimation_timer(unsigned long arg) 55 { 56 struct ip_vs_estimator *e; 57 struct ip_vs_stats *s; 58 u32 n_conns; 59 u32 n_inpkts, n_outpkts; 60 u64 n_inbytes, n_outbytes; 61 u32 rate; 62 63 spin_lock(&est_lock); 64 list_for_each_entry(e, &est_list, list) { 65 s = container_of(e, struct ip_vs_stats, est); 66 67 spin_lock(&s->lock); 68 n_conns = s->ustats.conns; 69 n_inpkts = s->ustats.inpkts; 70 n_outpkts = s->ustats.outpkts; 71 n_inbytes = s->ustats.inbytes; 72 n_outbytes = s->ustats.outbytes; 73 74 /* scaled by 2^10, but divided 2 seconds */ 75 rate = (n_conns - e->last_conns)<<9; 76 e->last_conns = n_conns; 77 e->cps += ((long)rate - (long)e->cps)>>2; 78 s->ustats.cps = (e->cps+0x1FF)>>10; 79 80 rate = (n_inpkts - e->last_inpkts)<<9; 81 e->last_inpkts = n_inpkts; 82 e->inpps += ((long)rate - (long)e->inpps)>>2; 83 s->ustats.inpps = (e->inpps+0x1FF)>>10; 84 85 rate = (n_outpkts - e->last_outpkts)<<9; 86 e->last_outpkts = n_outpkts; 87 e->outpps += ((long)rate - (long)e->outpps)>>2; 88 s->ustats.outpps = (e->outpps+0x1FF)>>10; 89 90 rate = (n_inbytes - e->last_inbytes)<<4; 91 e->last_inbytes = n_inbytes; 92 e->inbps += ((long)rate - (long)e->inbps)>>2; 93 s->ustats.inbps = (e->inbps+0xF)>>5; 94 95 rate = (n_outbytes - e->last_outbytes)<<4; 96 e->last_outbytes = n_outbytes; 97 e->outbps += ((long)rate - (long)e->outbps)>>2; 98 s->ustats.outbps = (e->outbps+0xF)>>5; 99 spin_unlock(&s->lock); 100 } 101 spin_unlock(&est_lock); 102 mod_timer(&est_timer, jiffies + 2*HZ); 103 } 104 105 void ip_vs_new_estimator(struct ip_vs_stats *stats) 106 { 107 struct ip_vs_estimator *est = &stats->est; 108 109 INIT_LIST_HEAD(&est->list); 110 111 est->last_conns = stats->ustats.conns; 112 est->cps = stats->ustats.cps<<10; 113 114 est->last_inpkts = stats->ustats.inpkts; 115 est->inpps = stats->ustats.inpps<<10; 116 117 est->last_outpkts = stats->ustats.outpkts; 118 est->outpps = stats->ustats.outpps<<10; 119 120 est->last_inbytes = stats->ustats.inbytes; 121 est->inbps = stats->ustats.inbps<<5; 122 123 est->last_outbytes = stats->ustats.outbytes; 124 est->outbps = stats->ustats.outbps<<5; 125 126 spin_lock_bh(&est_lock); 127 list_add(&est->list, &est_list); 128 spin_unlock_bh(&est_lock); 129 } 130 131 void ip_vs_kill_estimator(struct ip_vs_stats *stats) 132 { 133 struct ip_vs_estimator *est = &stats->est; 134 135 spin_lock_bh(&est_lock); 136 list_del(&est->list); 137 spin_unlock_bh(&est_lock); 138 } 139 140 void ip_vs_zero_estimator(struct ip_vs_stats *stats) 141 { 142 struct ip_vs_estimator *est = &stats->est; 143 144 /* set counters zero, caller must hold the stats->lock lock */ 145 est->last_inbytes = 0; 146 est->last_outbytes = 0; 147 est->last_conns = 0; 148 est->last_inpkts = 0; 149 est->last_outpkts = 0; 150 est->cps = 0; 151 est->inpps = 0; 152 est->outpps = 0; 153 est->inbps = 0; 154 est->outbps = 0; 155 } 156 157 int __init ip_vs_estimator_init(void) 158 { 159 mod_timer(&est_timer, jiffies + 2 * HZ); 160 return 0; 161 } 162 163 void ip_vs_estimator_cleanup(void) 164 { 165 del_timer_sync(&est_timer); 166 } 167