aboutsummaryrefslogtreecommitdiffstats
path: root/net/ipv4/ipvs/ip_vs_est.c
blob: dfa0d713c801b81dc6465feba8ad4ae3587d0ad1 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
/*
 * ip_vs_est.c: simple rate estimator for IPVS
 *
 * Version:     $Id: ip_vs_est.c,v 1.4 2002/11/30 01:50:35 wensong Exp $
 *
 * Authors:     Wensong Zhang <wensong@linuxvirtualserver.org>
 *
 *              This program is free software; you can redistribute it and/or
 *              modify it under the terms of the GNU General Public License
 *              as published by the Free Software Foundation; either version
 *              2 of the License, or (at your option) any later version.
 *
 * Changes:
 *
 */
#include <linux/kernel.h>
#include <linux/jiffies.h>
#include <linux/slab.h>
#include <linux/types.h>
#include <linux/interrupt.h>
#include <linux/sysctl.h>

#include <net/ip_vs.h>

/*
  This code is to estimate rate in a shorter interval (such as 8
  seconds) for virtual services and real servers. For measure rate in a
  long interval, it is easy to implement a user level daemon which
  periodically reads those statistical counters and measure rate.

  Currently, the measurement is activated by slow timer handler. Hope
  this measurement will not introduce too much load.

  We measure rate during the last 8 seconds every 2 seconds:

    avgrate = avgrate*(1-W) + rate*W

    where W = 2^(-2)

  NOTES.

  * The stored value for average bps is scaled by 2^5, so that maximal
    rate is ~2.15Gbits/s, average pps and cps are scaled by 2^10.

  * A lot code is taken from net/sched/estimator.c
 */


struct ip_vs_estimator
{
	struct ip_vs_estimator	*next;
	struct ip_vs_stats	*stats;

	u32			last_conns;
	u32			last_inpkts;
	u32			last_outpkts;
	u64			last_inbytes;
	u64			last_outbytes;

	u32			cps;
	u32			inpps;
	u32			outpps;
	u32			inbps;
	u32			outbps;
};


static struct ip_vs_estimator *est_list = NULL;
static DEFINE_RWLOCK(est_lock);
static struct timer_list est_timer;

static void estimation_timer(unsigned long arg)
{
	struct ip_vs_estimator *e;
	struct ip_vs_stats *s;
	u32 n_conns;
	u32 n_inpkts, n_outpkts;
	u64 n_inbytes, n_outbytes;
	u32 rate;

	read_lock(&est_lock);
	for (e = est_list; e; e = e->next) {
		s = e->stats;

		spin_lock(&s->lock);
		n_conns = s->conns;
		n_inpkts = s->inpkts;
		n_outpkts = s->outpkts;
		n_inbytes = s->inbytes;
		n_outbytes = s->outbytes;

		/* scaled by 2^10, but divided 2 seconds */
		rate = (n_conns - e->last_conns)<<9;
		e->last_conns = n_conns;
		e->cps += ((long)rate - (long)e->cps)>>2;
		s->cps = (e->cps+0x1FF)>>10;

		rate = (n_inpkts - e->last_inpkts)<<9;
		e->last_inpkts = n_inpkts;
		e->inpps += ((long)rate - (long)e->inpps)>>2;
		s->inpps = (e->inpps+0x1FF)>>10;

		rate = (n_outpkts - e->last_outpkts)<<9;
		e->last_outpkts = n_outpkts;
		e->outpps += ((long)rate - (long)e->outpps)>>2;
		s->outpps = (e->outpps+0x1FF)>>10;

		rate = (n_inbytes - e->last_inbytes)<<4;
		e->last_inbytes = n_inbytes;
		e->inbps += ((long)rate - (long)e->inbps)>>2;
		s->inbps = (e->inbps+0xF)>>5;

		rate = (n_outbytes - e->last_outbytes)<<4;
		e->last_outbytes = n_outbytes;
		e->outbps += ((long)rate - (long)e->outbps)>>2;
		s->outbps = (e->outbps+0xF)>>5;
		spin_unlock(&s->lock);
	}
	read_unlock(&est_lock);
	mod_timer(&est_timer, jiffies + 2*HZ);
}

int ip_vs_new_estimator(struct ip_vs_stats *stats)
{
	struct ip_vs_estimator *est;

	est = kzalloc(sizeof(*est), GFP_KERNEL);
	if (est == NULL)
		return -ENOMEM;

	est->stats = stats;
	est->last_conns = stats->conns;
	est->cps = stats->cps<<10;

	est->last_inpkts = stats->inpkts;
	est->inpps = stats->inpps<<10;

	est->last_outpkts = stats->outpkts;
	est->outpps = stats->outpps<<10;

	est->last_inbytes = stats->inbytes;
	est->inbps = stats->inbps<<5;

	est->last_outbytes = stats->outbytes;
	est->outbps = stats->outbps<<5;

	write_lock_bh(&est_lock);
	est->next = est_list;
	if (est->next == NULL) {
		setup_timer(&est_timer, estimation_timer, 0);
		est_timer.expires = jiffies + 2*HZ;
		add_timer(&est_timer);
	}
	est_list = est;
	write_unlock_bh(&est_lock);
	return 0;
}

void ip_vs_kill_estimator(struct ip_vs_stats *stats)
{
	struct ip_vs_estimator *est, **pest;
	int killed = 0;

	write_lock_bh(&est_lock);
	pest = &est_list;
	while ((est=*pest) != NULL) {
		if (est->stats != stats) {
			pest = &est->next;
			continue;
		}
		*pest = est->next;
		kfree(est);
		killed++;
	}
	if (killed && est_list == NULL)
		del_timer_sync(&est_timer);
	write_unlock_bh(&est_lock);
}

void ip_vs_zero_estimator(struct ip_vs_stats *stats)
{
	struct ip_vs_estimator *e;

	write_lock_bh(&est_lock);
	for (e = est_list; e; e = e->next) {
		if (e->stats != stats)
			continue;

		/* set counters zero */
		e->last_conns = 0;
		e->last_inpkts = 0;
		e->last_outpkts = 0;
		e->last_inbytes = 0;
		e->last_outbytes = 0;
		e->cps = 0;
		e->inpps = 0;
		e->outpps = 0;
		e->inbps = 0;
		e->outbps = 0;
	}
	write_unlock_bh(&est_lock);
}