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
.ip
), 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");