linux/net/ipv4/ipvs/ip_vs_rr.c
Sven Wegener 82dfb6f322 ipvs: Only call init_service, update_service and done_service for schedulers if defined
There are schedulers that only schedule based on data available in the service
or destination structures and they don't need any persistent storage or
initialization routine. These schedulers currently provide dummy functions for
the init_service, update_service and/or done_service functions. For the
init_service and done_service cases we already have code that only calls these
functions, if the scheduler provides them. Do the same for the update_service
case and remove the dummy functions from all schedulers.

Signed-off-by: Sven Wegener <sven.wegener@stealer.net>
Signed-off-by: Simon Horman <horms@verge.net.au>
2008-08-15 09:26:14 +10:00

110 lines
2.8 KiB
C

/*
* IPVS: Round-Robin Scheduling module
*
* Authors: Wensong Zhang <wensong@linuxvirtualserver.org>
* Peter Kese <peter.kese@ijs.si>
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*
* Fixes/Changes:
* Wensong Zhang : changed the ip_vs_rr_schedule to return dest
* Julian Anastasov : fixed the NULL pointer access bug in debugging
* Wensong Zhang : changed some comestics things for debugging
* Wensong Zhang : changed for the d-linked destination list
* Wensong Zhang : added the ip_vs_rr_update_svc
* Wensong Zhang : added any dest with weight=0 is quiesced
*
*/
#include <linux/module.h>
#include <linux/kernel.h>
#include <net/ip_vs.h>
static int ip_vs_rr_init_svc(struct ip_vs_service *svc)
{
svc->sched_data = &svc->destinations;
return 0;
}
static int ip_vs_rr_update_svc(struct ip_vs_service *svc)
{
svc->sched_data = &svc->destinations;
return 0;
}
/*
* Round-Robin Scheduling
*/
static struct ip_vs_dest *
ip_vs_rr_schedule(struct ip_vs_service *svc, const struct sk_buff *skb)
{
struct list_head *p, *q;
struct ip_vs_dest *dest;
IP_VS_DBG(6, "ip_vs_rr_schedule(): Scheduling...\n");
write_lock(&svc->sched_lock);
p = (struct list_head *)svc->sched_data;
p = p->next;
q = p;
do {
/* skip list head */
if (q == &svc->destinations) {
q = q->next;
continue;
}
dest = list_entry(q, struct ip_vs_dest, n_list);
if (!(dest->flags & IP_VS_DEST_F_OVERLOAD) &&
atomic_read(&dest->weight) > 0)
/* HIT */
goto out;
q = q->next;
} while (q != p);
write_unlock(&svc->sched_lock);
return NULL;
out:
svc->sched_data = q;
write_unlock(&svc->sched_lock);
IP_VS_DBG(6, "RR: server %u.%u.%u.%u:%u "
"activeconns %d refcnt %d weight %d\n",
NIPQUAD(dest->addr), ntohs(dest->port),
atomic_read(&dest->activeconns),
atomic_read(&dest->refcnt), atomic_read(&dest->weight));
return dest;
}
static struct ip_vs_scheduler ip_vs_rr_scheduler = {
.name = "rr", /* name */
.refcnt = ATOMIC_INIT(0),
.module = THIS_MODULE,
.n_list = LIST_HEAD_INIT(ip_vs_rr_scheduler.n_list),
.init_service = ip_vs_rr_init_svc,
.update_service = ip_vs_rr_update_svc,
.schedule = ip_vs_rr_schedule,
};
static int __init ip_vs_rr_init(void)
{
return register_ip_vs_scheduler(&ip_vs_rr_scheduler);
}
static void __exit ip_vs_rr_cleanup(void)
{
unregister_ip_vs_scheduler(&ip_vs_rr_scheduler);
}
module_init(ip_vs_rr_init);
module_exit(ip_vs_rr_cleanup);
MODULE_LICENSE("GPL");