2 * ip_vs_est.c: simple rate estimator for IPVS
4 * Version: $Id: ip_vs_est.c,v 1.4 2002/11/30 01:50:35 wensong Exp $
6 * Authors: Wensong Zhang <wensong@linuxvirtualserver.org>
8 * This program is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU General Public License
10 * as published by the Free Software Foundation; either version
11 * 2 of the License, or (at your option) any later version.
16 #include <linux/kernel.h>
17 #include <linux/types.h>
19 #include <net/ip_vs.h>
22 This code is to estimate rate in a shorter interval (such as 8
23 seconds) for virtual services and real servers. For measure rate in a
24 long interval, it is easy to implement a user level daemon which
25 periodically reads those statistical counters and measure rate.
27 Currently, the measurement is activated by slow timer handler. Hope
28 this measurement will not introduce too much load.
30 We measure rate during the last 8 seconds every 2 seconds:
32 avgrate = avgrate*(1-W) + rate*W
38 * The stored value for average bps is scaled by 2^5, so that maximal
39 rate is ~2.15Gbits/s, average pps and cps are scaled by 2^10.
41 * A lot code is taken from net/sched/estimator.c
45 struct ip_vs_estimator
47 struct ip_vs_estimator *next;
48 struct ip_vs_stats *stats;
64 static struct ip_vs_estimator *est_list = NULL;
65 static rwlock_t est_lock = RW_LOCK_UNLOCKED;
66 static struct timer_list est_timer;
68 static void estimation_timer(unsigned long arg)
70 struct ip_vs_estimator *e;
71 struct ip_vs_stats *s;
73 u32 n_inpkts, n_outpkts;
74 u64 n_inbytes, n_outbytes;
78 for (e = est_list; e; e = e->next) {
82 n_outpkts = s->outpkts;
83 n_inbytes = s->inbytes;
84 n_outbytes = s->outbytes;
86 /* scaled by 2^10, but divided 2 seconds */
87 rate = (n_conns - e->last_conns)<<9;
88 e->last_conns = n_conns;
89 e->cps += ((long)rate - (long)e->cps)>>2;
90 s->cps = (e->cps+0x1FF)>>10;
92 rate = (n_inpkts - e->last_inpkts)<<9;
93 e->last_inpkts = n_inpkts;
94 e->inpps += ((long)rate - (long)e->inpps)>>2;
95 s->inpps = (e->inpps+0x1FF)>>10;
97 rate = (n_outpkts - e->last_outpkts)<<9;
98 e->last_outpkts = n_outpkts;
99 e->outpps += ((long)rate - (long)e->outpps)>>2;
100 s->outpps = (e->outpps+0x1FF)>>10;
102 rate = (n_inbytes - e->last_inbytes)<<4;
103 e->last_inbytes = n_inbytes;
104 e->inbps += ((long)rate - (long)e->inbps)>>2;
105 s->inbps = (e->inbps+0xF)>>5;
107 rate = (n_outbytes - e->last_outbytes)<<4;
108 e->last_outbytes = n_outbytes;
109 e->outbps += ((long)rate - (long)e->outbps)>>2;
110 s->outbps = (e->outbps+0xF)>>5;
112 read_unlock(&est_lock);
113 mod_timer(&est_timer, jiffies + 2*HZ);
116 int ip_vs_new_estimator(struct ip_vs_stats *stats)
118 struct ip_vs_estimator *est;
120 est = kmalloc(sizeof(*est), GFP_KERNEL);
124 memset(est, 0, sizeof(*est));
126 est->last_conns = stats->conns;
127 est->cps = stats->cps<<10;
129 est->last_inpkts = stats->inpkts;
130 est->inpps = stats->inpps<<10;
132 est->last_outpkts = stats->outpkts;
133 est->outpps = stats->outpps<<10;
135 est->last_inbytes = stats->inbytes;
136 est->inbps = stats->inbps<<5;
138 est->last_outbytes = stats->outbytes;
139 est->outbps = stats->outbps<<5;
141 write_lock_bh(&est_lock);
142 est->next = est_list;
143 if (est->next == NULL) {
144 init_timer(&est_timer);
145 est_timer.expires = jiffies + 2*HZ;
146 est_timer.function = estimation_timer;
147 add_timer(&est_timer);
150 write_unlock_bh(&est_lock);
154 void ip_vs_kill_estimator(struct ip_vs_stats *stats)
156 struct ip_vs_estimator *est, **pest;
159 write_lock_bh(&est_lock);
161 while ((est=*pest) != NULL) {
162 if (est->stats != stats) {
170 if (killed && est_list == NULL)
171 del_timer_sync(&est_timer);
172 write_unlock_bh(&est_lock);
175 void ip_vs_zero_estimator(struct ip_vs_stats *stats)
177 struct ip_vs_estimator *e;
179 write_lock_bh(&est_lock);
180 for (e = est_list; e; e = e->next) {
181 if (e->stats != stats)
184 /* set counters zero */
189 e->last_outbytes = 0;
196 write_unlock_bh(&est_lock);