2 * IPVS: Round-Robin Scheduling module
4 * Authors: Wensong Zhang <wensong@linuxvirtualserver.org>
5 * Peter Kese <peter.kese@ijs.si>
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.
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
22 #include <linux/module.h>
23 #include <linux/kernel.h>
25 #include <net/ip_vs.h>
28 static int ip_vs_rr_init_svc(struct ip_vs_service *svc)
30 svc->sched_data = &svc->destinations;
35 static int ip_vs_rr_update_svc(struct ip_vs_service *svc)
37 svc->sched_data = &svc->destinations;
43 * Round-Robin Scheduling
45 static struct ip_vs_dest *
46 ip_vs_rr_schedule(struct ip_vs_service *svc, const struct sk_buff *skb)
48 struct list_head *p, *q;
49 struct ip_vs_dest *dest;
51 IP_VS_DBG(6, "ip_vs_rr_schedule(): Scheduling...\n");
53 write_lock(&svc->sched_lock);
54 p = (struct list_head *)svc->sched_data;
59 if (q == &svc->destinations) {
64 dest = list_entry(q, struct ip_vs_dest, n_list);
65 if (!(dest->flags & IP_VS_DEST_F_OVERLOAD) &&
66 atomic_read(&dest->weight) > 0)
71 write_unlock(&svc->sched_lock);
76 write_unlock(&svc->sched_lock);
77 IP_VS_DBG(6, "RR: server %u.%u.%u.%u:%u "
78 "activeconns %d refcnt %d weight %d\n",
79 NIPQUAD(dest->addr), ntohs(dest->port),
80 atomic_read(&dest->activeconns),
81 atomic_read(&dest->refcnt), atomic_read(&dest->weight));
87 static struct ip_vs_scheduler ip_vs_rr_scheduler = {
88 .name = "rr", /* name */
89 .refcnt = ATOMIC_INIT(0),
90 .module = THIS_MODULE,
91 .n_list = LIST_HEAD_INIT(ip_vs_rr_scheduler.n_list),
92 .init_service = ip_vs_rr_init_svc,
93 .update_service = ip_vs_rr_update_svc,
94 .schedule = ip_vs_rr_schedule,
97 static int __init ip_vs_rr_init(void)
99 return register_ip_vs_scheduler(&ip_vs_rr_scheduler);
102 static void __exit ip_vs_rr_cleanup(void)
104 unregister_ip_vs_scheduler(&ip_vs_rr_scheduler);
107 module_init(ip_vs_rr_init);
108 module_exit(ip_vs_rr_cleanup);
109 MODULE_LICENSE("GPL");