diff options
Diffstat (limited to 'net/ipv4/ipvs/ip_vs_nq.c')
-rw-r--r-- | net/ipv4/ipvs/ip_vs_nq.c | 138 |
1 files changed, 0 insertions, 138 deletions
diff --git a/net/ipv4/ipvs/ip_vs_nq.c b/net/ipv4/ipvs/ip_vs_nq.c deleted file mode 100644 index 9a2d8033f08f..000000000000 --- a/net/ipv4/ipvs/ip_vs_nq.c +++ /dev/null | |||
@@ -1,138 +0,0 @@ | |||
1 | /* | ||
2 | * IPVS: Never Queue scheduling module | ||
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 | /* | ||
16 | * The NQ algorithm adopts a two-speed model. When there is an idle server | ||
17 | * available, the job will be sent to the idle server, instead of waiting | ||
18 | * for a fast one. When there is no idle server available, the job will be | ||
19 | * sent to the server that minimize its expected delay (The Shortest | ||
20 | * Expected Delay scheduling algorithm). | ||
21 | * | ||
22 | * See the following paper for more information: | ||
23 | * A. Weinrib and S. Shenker, Greed is not enough: Adaptive load sharing | ||
24 | * in large heterogeneous systems. In Proceedings IEEE INFOCOM'88, | ||
25 | * pages 986-994, 1988. | ||
26 | * | ||
27 | * Thanks must go to Marko Buuri <marko@buuri.name> for talking NQ to me. | ||
28 | * | ||
29 | * The difference between NQ and SED is that NQ can improve overall | ||
30 | * system utilization. | ||
31 | * | ||
32 | */ | ||
33 | |||
34 | #include <linux/module.h> | ||
35 | #include <linux/kernel.h> | ||
36 | |||
37 | #include <net/ip_vs.h> | ||
38 | |||
39 | |||
40 | static inline unsigned int | ||
41 | ip_vs_nq_dest_overhead(struct ip_vs_dest *dest) | ||
42 | { | ||
43 | /* | ||
44 | * We only use the active connection number in the cost | ||
45 | * calculation here. | ||
46 | */ | ||
47 | return atomic_read(&dest->activeconns) + 1; | ||
48 | } | ||
49 | |||
50 | |||
51 | /* | ||
52 | * Weighted Least Connection scheduling | ||
53 | */ | ||
54 | static struct ip_vs_dest * | ||
55 | ip_vs_nq_schedule(struct ip_vs_service *svc, const struct sk_buff *skb) | ||
56 | { | ||
57 | struct ip_vs_dest *dest, *least = NULL; | ||
58 | unsigned int loh = 0, doh; | ||
59 | |||
60 | IP_VS_DBG(6, "ip_vs_nq_schedule(): Scheduling...\n"); | ||
61 | |||
62 | /* | ||
63 | * We calculate the load of each dest server as follows: | ||
64 | * (server expected overhead) / dest->weight | ||
65 | * | ||
66 | * Remember -- no floats in kernel mode!!! | ||
67 | * The comparison of h1*w2 > h2*w1 is equivalent to that of | ||
68 | * h1/w1 > h2/w2 | ||
69 | * if every weight is larger than zero. | ||
70 | * | ||
71 | * The server with weight=0 is quiesced and will not receive any | ||
72 | * new connections. | ||
73 | */ | ||
74 | |||
75 | list_for_each_entry(dest, &svc->destinations, n_list) { | ||
76 | |||
77 | if (dest->flags & IP_VS_DEST_F_OVERLOAD || | ||
78 | !atomic_read(&dest->weight)) | ||
79 | continue; | ||
80 | |||
81 | doh = ip_vs_nq_dest_overhead(dest); | ||
82 | |||
83 | /* return the server directly if it is idle */ | ||
84 | if (atomic_read(&dest->activeconns) == 0) { | ||
85 | least = dest; | ||
86 | loh = doh; | ||
87 | goto out; | ||
88 | } | ||
89 | |||
90 | if (!least || | ||
91 | (loh * atomic_read(&dest->weight) > | ||
92 | doh * atomic_read(&least->weight))) { | ||
93 | least = dest; | ||
94 | loh = doh; | ||
95 | } | ||
96 | } | ||
97 | |||
98 | if (!least) | ||
99 | return NULL; | ||
100 | |||
101 | out: | ||
102 | IP_VS_DBG_BUF(6, "NQ: server %s:%u " | ||
103 | "activeconns %d refcnt %d weight %d overhead %d\n", | ||
104 | IP_VS_DBG_ADDR(svc->af, &least->addr), ntohs(least->port), | ||
105 | atomic_read(&least->activeconns), | ||
106 | atomic_read(&least->refcnt), | ||
107 | atomic_read(&least->weight), loh); | ||
108 | |||
109 | return least; | ||
110 | } | ||
111 | |||
112 | |||
113 | static struct ip_vs_scheduler ip_vs_nq_scheduler = | ||
114 | { | ||
115 | .name = "nq", | ||
116 | .refcnt = ATOMIC_INIT(0), | ||
117 | .module = THIS_MODULE, | ||
118 | .n_list = LIST_HEAD_INIT(ip_vs_nq_scheduler.n_list), | ||
119 | #ifdef CONFIG_IP_VS_IPV6 | ||
120 | .supports_ipv6 = 1, | ||
121 | #endif | ||
122 | .schedule = ip_vs_nq_schedule, | ||
123 | }; | ||
124 | |||
125 | |||
126 | static int __init ip_vs_nq_init(void) | ||
127 | { | ||
128 | return register_ip_vs_scheduler(&ip_vs_nq_scheduler); | ||
129 | } | ||
130 | |||
131 | static void __exit ip_vs_nq_cleanup(void) | ||
132 | { | ||
133 | unregister_ip_vs_scheduler(&ip_vs_nq_scheduler); | ||
134 | } | ||
135 | |||
136 | module_init(ip_vs_nq_init); | ||
137 | module_exit(ip_vs_nq_cleanup); | ||
138 | MODULE_LICENSE("GPL"); | ||