b552f7e3a9
lc and wlc use the same formula, but lblc and lblcr use another one. There is no reason for using two different formulas for the lc variants. The formula used by lc is used by all the lc variants in this patch. Signed-off-by: Changli Gao <xiaosuo@gmail.com> Acked-by: Wensong Zhang <wensong@linux-vs.org> Signed-off-by: Simon Horman <horms@verge.net.au>
114 lines
3.2 KiB
C
114 lines
3.2 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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#define KMSG_COMPONENT "IPVS"
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#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
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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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/*
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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_dest_conn_overhead(least);
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goto nextstage;
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}
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}
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ip_vs_scheduler_err(svc, "no destination available");
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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_dest_conn_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_BUF(6, "WLC: server %s:%u "
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"activeconns %d refcnt %d weight %d overhead %d\n",
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IP_VS_DBG_ADDR(svc->af, &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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