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82dfb6f322
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>
126 lines
3.5 KiB
C
126 lines
3.5 KiB
C
/*
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* IPVS: Weighted Least-Connection Scheduling module
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*
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* Authors: Wensong Zhang <wensong@linuxvirtualserver.org>
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* Peter Kese <peter.kese@ijs.si>
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version
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* 2 of the License, or (at your option) any later version.
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*
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* Changes:
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* Wensong Zhang : changed the ip_vs_wlc_schedule to return dest
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* Wensong Zhang : changed to use the inactconns in scheduling
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* Wensong Zhang : changed some comestics things for debugging
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* Wensong Zhang : changed for the d-linked destination list
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* Wensong Zhang : added the ip_vs_wlc_update_svc
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* Wensong Zhang : added any dest with weight=0 is quiesced
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*
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*/
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#include <linux/module.h>
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#include <linux/kernel.h>
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#include <net/ip_vs.h>
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static inline unsigned int
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ip_vs_wlc_dest_overhead(struct ip_vs_dest *dest)
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{
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/*
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* We think the overhead of processing active connections is 256
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* times higher than that of inactive connections in average. (This
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* 256 times might not be accurate, we will change it later) We
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* use the following formula to estimate the overhead now:
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* dest->activeconns*256 + dest->inactconns
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*/
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return (atomic_read(&dest->activeconns) << 8) +
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atomic_read(&dest->inactconns);
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}
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/*
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* Weighted Least Connection scheduling
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*/
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static struct ip_vs_dest *
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ip_vs_wlc_schedule(struct ip_vs_service *svc, const struct sk_buff *skb)
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{
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struct ip_vs_dest *dest, *least;
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unsigned int loh, doh;
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IP_VS_DBG(6, "ip_vs_wlc_schedule(): Scheduling...\n");
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/*
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* We calculate the load of each dest server as follows:
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* (dest overhead) / dest->weight
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*
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* Remember -- no floats in kernel mode!!!
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* The comparison of h1*w2 > h2*w1 is equivalent to that of
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* h1/w1 > h2/w2
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* if every weight is larger than zero.
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*
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* The server with weight=0 is quiesced and will not receive any
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* new connections.
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*/
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list_for_each_entry(dest, &svc->destinations, n_list) {
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if (!(dest->flags & IP_VS_DEST_F_OVERLOAD) &&
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atomic_read(&dest->weight) > 0) {
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least = dest;
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loh = ip_vs_wlc_dest_overhead(least);
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goto nextstage;
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}
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}
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return NULL;
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/*
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* Find the destination with the least load.
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*/
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nextstage:
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list_for_each_entry_continue(dest, &svc->destinations, n_list) {
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if (dest->flags & IP_VS_DEST_F_OVERLOAD)
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continue;
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doh = ip_vs_wlc_dest_overhead(dest);
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if (loh * atomic_read(&dest->weight) >
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doh * atomic_read(&least->weight)) {
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least = dest;
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loh = doh;
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}
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}
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IP_VS_DBG(6, "WLC: server %u.%u.%u.%u:%u "
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"activeconns %d refcnt %d weight %d overhead %d\n",
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NIPQUAD(least->addr), ntohs(least->port),
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atomic_read(&least->activeconns),
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atomic_read(&least->refcnt),
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atomic_read(&least->weight), loh);
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return least;
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}
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static struct ip_vs_scheduler ip_vs_wlc_scheduler =
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{
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.name = "wlc",
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.refcnt = ATOMIC_INIT(0),
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.module = THIS_MODULE,
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.n_list = LIST_HEAD_INIT(ip_vs_wlc_scheduler.n_list),
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.schedule = ip_vs_wlc_schedule,
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};
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static int __init ip_vs_wlc_init(void)
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{
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return register_ip_vs_scheduler(&ip_vs_wlc_scheduler);
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}
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static void __exit ip_vs_wlc_cleanup(void)
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{
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unregister_ip_vs_scheduler(&ip_vs_wlc_scheduler);
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}
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module_init(ip_vs_wlc_init);
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module_exit(ip_vs_wlc_cleanup);
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MODULE_LICENSE("GPL");
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