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1da177e4 LT |
1 | /* |
2 | * ip_vs_est.c: simple rate estimator for IPVS | |
3 | * | |
1da177e4 LT |
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> | |
14c85021 ACM |
15 | #include <linux/jiffies.h> |
16 | #include <linux/slab.h> | |
1da177e4 | 17 | #include <linux/types.h> |
4ffd2e49 | 18 | #include <linux/interrupt.h> |
90754f8e | 19 | #include <linux/sysctl.h> |
1da177e4 LT |
20 | |
21 | #include <net/ip_vs.h> | |
22 | ||
23 | /* | |
24 | This code is to estimate rate in a shorter interval (such as 8 | |
25 | seconds) for virtual services and real servers. For measure rate in a | |
26 | long interval, it is easy to implement a user level daemon which | |
27 | periodically reads those statistical counters and measure rate. | |
28 | ||
29 | Currently, the measurement is activated by slow timer handler. Hope | |
30 | this measurement will not introduce too much load. | |
31 | ||
32 | We measure rate during the last 8 seconds every 2 seconds: | |
33 | ||
34 | avgrate = avgrate*(1-W) + rate*W | |
35 | ||
36 | where W = 2^(-2) | |
37 | ||
38 | NOTES. | |
39 | ||
40 | * The stored value for average bps is scaled by 2^5, so that maximal | |
41 | rate is ~2.15Gbits/s, average pps and cps are scaled by 2^10. | |
42 | ||
43 | * A lot code is taken from net/sched/estimator.c | |
44 | */ | |
45 | ||
46 | ||
47 | struct ip_vs_estimator | |
48 | { | |
49 | struct ip_vs_estimator *next; | |
50 | struct ip_vs_stats *stats; | |
51 | ||
52 | u32 last_conns; | |
53 | u32 last_inpkts; | |
54 | u32 last_outpkts; | |
55 | u64 last_inbytes; | |
56 | u64 last_outbytes; | |
57 | ||
58 | u32 cps; | |
59 | u32 inpps; | |
60 | u32 outpps; | |
61 | u32 inbps; | |
62 | u32 outbps; | |
63 | }; | |
64 | ||
65 | ||
66 | static struct ip_vs_estimator *est_list = NULL; | |
67 | static DEFINE_RWLOCK(est_lock); | |
68 | static struct timer_list est_timer; | |
69 | ||
70 | static void estimation_timer(unsigned long arg) | |
71 | { | |
72 | struct ip_vs_estimator *e; | |
73 | struct ip_vs_stats *s; | |
74 | u32 n_conns; | |
75 | u32 n_inpkts, n_outpkts; | |
76 | u64 n_inbytes, n_outbytes; | |
77 | u32 rate; | |
78 | ||
79 | read_lock(&est_lock); | |
80 | for (e = est_list; e; e = e->next) { | |
81 | s = e->stats; | |
82 | ||
83 | spin_lock(&s->lock); | |
84 | n_conns = s->conns; | |
85 | n_inpkts = s->inpkts; | |
86 | n_outpkts = s->outpkts; | |
87 | n_inbytes = s->inbytes; | |
88 | n_outbytes = s->outbytes; | |
89 | ||
90 | /* scaled by 2^10, but divided 2 seconds */ | |
91 | rate = (n_conns - e->last_conns)<<9; | |
92 | e->last_conns = n_conns; | |
93 | e->cps += ((long)rate - (long)e->cps)>>2; | |
94 | s->cps = (e->cps+0x1FF)>>10; | |
95 | ||
96 | rate = (n_inpkts - e->last_inpkts)<<9; | |
97 | e->last_inpkts = n_inpkts; | |
98 | e->inpps += ((long)rate - (long)e->inpps)>>2; | |
99 | s->inpps = (e->inpps+0x1FF)>>10; | |
100 | ||
101 | rate = (n_outpkts - e->last_outpkts)<<9; | |
102 | e->last_outpkts = n_outpkts; | |
103 | e->outpps += ((long)rate - (long)e->outpps)>>2; | |
104 | s->outpps = (e->outpps+0x1FF)>>10; | |
105 | ||
106 | rate = (n_inbytes - e->last_inbytes)<<4; | |
107 | e->last_inbytes = n_inbytes; | |
108 | e->inbps += ((long)rate - (long)e->inbps)>>2; | |
109 | s->inbps = (e->inbps+0xF)>>5; | |
110 | ||
111 | rate = (n_outbytes - e->last_outbytes)<<4; | |
112 | e->last_outbytes = n_outbytes; | |
113 | e->outbps += ((long)rate - (long)e->outbps)>>2; | |
114 | s->outbps = (e->outbps+0xF)>>5; | |
115 | spin_unlock(&s->lock); | |
116 | } | |
117 | read_unlock(&est_lock); | |
118 | mod_timer(&est_timer, jiffies + 2*HZ); | |
119 | } | |
120 | ||
121 | int ip_vs_new_estimator(struct ip_vs_stats *stats) | |
122 | { | |
123 | struct ip_vs_estimator *est; | |
124 | ||
0da974f4 | 125 | est = kzalloc(sizeof(*est), GFP_KERNEL); |
1da177e4 LT |
126 | if (est == NULL) |
127 | return -ENOMEM; | |
128 | ||
1da177e4 LT |
129 | est->stats = stats; |
130 | est->last_conns = stats->conns; | |
131 | est->cps = stats->cps<<10; | |
132 | ||
133 | est->last_inpkts = stats->inpkts; | |
134 | est->inpps = stats->inpps<<10; | |
135 | ||
136 | est->last_outpkts = stats->outpkts; | |
137 | est->outpps = stats->outpps<<10; | |
138 | ||
139 | est->last_inbytes = stats->inbytes; | |
140 | est->inbps = stats->inbps<<5; | |
141 | ||
142 | est->last_outbytes = stats->outbytes; | |
143 | est->outbps = stats->outbps<<5; | |
144 | ||
145 | write_lock_bh(&est_lock); | |
146 | est->next = est_list; | |
147 | if (est->next == NULL) { | |
b24b8a24 | 148 | setup_timer(&est_timer, estimation_timer, 0); |
1da177e4 | 149 | est_timer.expires = jiffies + 2*HZ; |
1da177e4 LT |
150 | add_timer(&est_timer); |
151 | } | |
152 | est_list = est; | |
153 | write_unlock_bh(&est_lock); | |
154 | return 0; | |
155 | } | |
156 | ||
157 | void ip_vs_kill_estimator(struct ip_vs_stats *stats) | |
158 | { | |
159 | struct ip_vs_estimator *est, **pest; | |
160 | int killed = 0; | |
161 | ||
162 | write_lock_bh(&est_lock); | |
163 | pest = &est_list; | |
164 | while ((est=*pest) != NULL) { | |
165 | if (est->stats != stats) { | |
166 | pest = &est->next; | |
167 | continue; | |
168 | } | |
169 | *pest = est->next; | |
170 | kfree(est); | |
171 | killed++; | |
172 | } | |
173 | if (killed && est_list == NULL) | |
174 | del_timer_sync(&est_timer); | |
175 | write_unlock_bh(&est_lock); | |
176 | } | |
177 | ||
178 | void ip_vs_zero_estimator(struct ip_vs_stats *stats) | |
179 | { | |
180 | struct ip_vs_estimator *e; | |
181 | ||
182 | write_lock_bh(&est_lock); | |
183 | for (e = est_list; e; e = e->next) { | |
184 | if (e->stats != stats) | |
185 | continue; | |
186 | ||
187 | /* set counters zero */ | |
188 | e->last_conns = 0; | |
189 | e->last_inpkts = 0; | |
190 | e->last_outpkts = 0; | |
191 | e->last_inbytes = 0; | |
192 | e->last_outbytes = 0; | |
193 | e->cps = 0; | |
194 | e->inpps = 0; | |
195 | e->outpps = 0; | |
196 | e->inbps = 0; | |
197 | e->outbps = 0; | |
198 | } | |
199 | write_unlock_bh(&est_lock); | |
200 | } |