]>
Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | /* |
2 | * IPVS: Round-Robin Scheduling module | |
3 | * | |
1da177e4 LT |
4 | * Authors: Wensong Zhang <wensong@linuxvirtualserver.org> |
5 | * Peter Kese <peter.kese@ijs.si> | |
6 | * | |
7 | * This program is free software; you can redistribute it and/or | |
8 | * modify it under the terms of the GNU General Public License | |
9 | * as published by the Free Software Foundation; either version | |
10 | * 2 of the License, or (at your option) any later version. | |
11 | * | |
12 | * Fixes/Changes: | |
13 | * Wensong Zhang : changed the ip_vs_rr_schedule to return dest | |
14 | * Julian Anastasov : fixed the NULL pointer access bug in debugging | |
15 | * Wensong Zhang : changed some comestics things for debugging | |
16 | * Wensong Zhang : changed for the d-linked destination list | |
17 | * Wensong Zhang : added the ip_vs_rr_update_svc | |
18 | * Wensong Zhang : added any dest with weight=0 is quiesced | |
19 | * | |
20 | */ | |
21 | ||
9aada7ac HE |
22 | #define KMSG_COMPONENT "IPVS" |
23 | #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt | |
24 | ||
1da177e4 LT |
25 | #include <linux/module.h> |
26 | #include <linux/kernel.h> | |
27 | ||
28 | #include <net/ip_vs.h> | |
29 | ||
30 | ||
31 | static int ip_vs_rr_init_svc(struct ip_vs_service *svc) | |
32 | { | |
33 | svc->sched_data = &svc->destinations; | |
34 | return 0; | |
35 | } | |
36 | ||
37 | ||
1da177e4 LT |
38 | static int ip_vs_rr_update_svc(struct ip_vs_service *svc) |
39 | { | |
40 | svc->sched_data = &svc->destinations; | |
41 | return 0; | |
42 | } | |
43 | ||
44 | ||
45 | /* | |
46 | * Round-Robin Scheduling | |
47 | */ | |
48 | static struct ip_vs_dest * | |
49 | ip_vs_rr_schedule(struct ip_vs_service *svc, const struct sk_buff *skb) | |
50 | { | |
51 | struct list_head *p, *q; | |
52 | struct ip_vs_dest *dest; | |
53 | ||
1e3e238e | 54 | IP_VS_DBG(6, "%s(): Scheduling...\n", __func__); |
1da177e4 LT |
55 | |
56 | write_lock(&svc->sched_lock); | |
57 | p = (struct list_head *)svc->sched_data; | |
58 | p = p->next; | |
59 | q = p; | |
60 | do { | |
61 | /* skip list head */ | |
62 | if (q == &svc->destinations) { | |
63 | q = q->next; | |
64 | continue; | |
65 | } | |
e905a9ed | 66 | |
1da177e4 LT |
67 | dest = list_entry(q, struct ip_vs_dest, n_list); |
68 | if (!(dest->flags & IP_VS_DEST_F_OVERLOAD) && | |
69 | atomic_read(&dest->weight) > 0) | |
70 | /* HIT */ | |
71 | goto out; | |
72 | q = q->next; | |
73 | } while (q != p); | |
74 | write_unlock(&svc->sched_lock); | |
68888d10 | 75 | IP_VS_ERR_RL("RR: no destination available\n"); |
1da177e4 LT |
76 | return NULL; |
77 | ||
78 | out: | |
79 | svc->sched_data = q; | |
80 | write_unlock(&svc->sched_lock); | |
b14198f6 JV |
81 | IP_VS_DBG_BUF(6, "RR: server %s:%u " |
82 | "activeconns %d refcnt %d weight %d\n", | |
83 | IP_VS_DBG_ADDR(svc->af, &dest->addr), ntohs(dest->port), | |
84 | atomic_read(&dest->activeconns), | |
85 | atomic_read(&dest->refcnt), atomic_read(&dest->weight)); | |
1da177e4 LT |
86 | |
87 | return dest; | |
88 | } | |
89 | ||
90 | ||
91 | static struct ip_vs_scheduler ip_vs_rr_scheduler = { | |
92 | .name = "rr", /* name */ | |
93 | .refcnt = ATOMIC_INIT(0), | |
94 | .module = THIS_MODULE, | |
d149ccc9 | 95 | .n_list = LIST_HEAD_INIT(ip_vs_rr_scheduler.n_list), |
1da177e4 | 96 | .init_service = ip_vs_rr_init_svc, |
1da177e4 LT |
97 | .update_service = ip_vs_rr_update_svc, |
98 | .schedule = ip_vs_rr_schedule, | |
99 | }; | |
100 | ||
101 | static int __init ip_vs_rr_init(void) | |
102 | { | |
1da177e4 LT |
103 | return register_ip_vs_scheduler(&ip_vs_rr_scheduler); |
104 | } | |
105 | ||
106 | static void __exit ip_vs_rr_cleanup(void) | |
107 | { | |
108 | unregister_ip_vs_scheduler(&ip_vs_rr_scheduler); | |
109 | } | |
110 | ||
111 | module_init(ip_vs_rr_init); | |
112 | module_exit(ip_vs_rr_cleanup); | |
113 | MODULE_LICENSE("GPL"); |