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![Thomas Gleixner](/assets/img/avatar_default.png)
Based on 1 normalized pattern(s): 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 extracted by the scancode license scanner the SPDX license identifier GPL-2.0-or-later has been chosen to replace the boilerplate/reference in 3029 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Allison Randal <allison@lohutok.net> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
88 lines
2.2 KiB
C
88 lines
2.2 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
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/*
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* IPVS: Least-Connection Scheduling module
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*
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* Authors: Wensong Zhang <wensong@linuxvirtualserver.org>
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*
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* Changes:
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* Wensong Zhang : added the ip_vs_lc_update_svc
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* Wensong Zhang : added any dest with weight=0 is quiesced
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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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* Least Connection scheduling
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*/
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static struct ip_vs_dest *
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ip_vs_lc_schedule(struct ip_vs_service *svc, const struct sk_buff *skb,
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struct ip_vs_iphdr *iph)
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{
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struct ip_vs_dest *dest, *least = NULL;
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unsigned int loh = 0, doh;
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IP_VS_DBG(6, "%s(): Scheduling...\n", __func__);
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/*
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* Simply select the server with the least number of
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* (activeconns<<5) + inactconns
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* Except whose weight is equal to zero.
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* If the weight is equal to zero, it means that the server is
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* quiesced, the existing connections to the server still get
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* served, but no new connection is assigned to the server.
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*/
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list_for_each_entry_rcu(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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continue;
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doh = ip_vs_dest_conn_overhead(dest);
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if (!least || doh < loh) {
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least = dest;
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loh = doh;
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}
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}
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if (!least)
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ip_vs_scheduler_err(svc, "no destination available");
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else
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IP_VS_DBG_BUF(6, "LC: server %s:%u activeconns %d "
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"inactconns %d\n",
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IP_VS_DBG_ADDR(least->af, &least->addr),
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ntohs(least->port),
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atomic_read(&least->activeconns),
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atomic_read(&least->inactconns));
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return least;
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}
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static struct ip_vs_scheduler ip_vs_lc_scheduler = {
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.name = "lc",
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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_lc_scheduler.n_list),
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.schedule = ip_vs_lc_schedule,
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};
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static int __init ip_vs_lc_init(void)
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{
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return register_ip_vs_scheduler(&ip_vs_lc_scheduler) ;
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}
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static void __exit ip_vs_lc_cleanup(void)
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{
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unregister_ip_vs_scheduler(&ip_vs_lc_scheduler);
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synchronize_rcu();
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}
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module_init(ip_vs_lc_init);
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module_exit(ip_vs_lc_cleanup);
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MODULE_LICENSE("GPL");
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