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-rw-r--r--net/ipv4/ipvs/ip_vs_nq.c138
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
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@@ -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
40static inline unsigned int
41ip_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 */
54static struct ip_vs_dest *
55ip_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
113static 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
126static int __init ip_vs_nq_init(void)
127{
128 return register_ip_vs_scheduler(&ip_vs_nq_scheduler);
129}
130
131static void __exit ip_vs_nq_cleanup(void)
132{
133 unregister_ip_vs_scheduler(&ip_vs_nq_scheduler);
134}
135
136module_init(ip_vs_nq_init);
137module_exit(ip_vs_nq_cleanup);
138MODULE_LICENSE("GPL");