linux-brain/net/netfilter/ipvs/ip_vs_ovf.c
Thomas Gleixner 2874c5fd28 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152
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>
2019-05-30 11:26:32 -07:00

82 lines
2.1 KiB
C

// SPDX-License-Identifier: GPL-2.0-or-later
/*
* IPVS: Overflow-Connection Scheduling module
*
* Authors: Raducu Deaconu <rhadoo_io@yahoo.com>
*
* Scheduler implements "overflow" loadbalancing according to number of active
* connections , will keep all conections to the node with the highest weight
* and overflow to the next node if the number of connections exceeds the node's
* weight.
* Note that this scheduler might not be suitable for UDP because it only uses
* active connections
*/
#define KMSG_COMPONENT "IPVS"
#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
#include <linux/module.h>
#include <linux/kernel.h>
#include <net/ip_vs.h>
/* OVF Connection scheduling */
static struct ip_vs_dest *
ip_vs_ovf_schedule(struct ip_vs_service *svc, const struct sk_buff *skb,
struct ip_vs_iphdr *iph)
{
struct ip_vs_dest *dest, *h = NULL;
int hw = 0, w;
IP_VS_DBG(6, "ip_vs_ovf_schedule(): Scheduling...\n");
/* select the node with highest weight, go to next in line if active
* connections exceed weight
*/
list_for_each_entry_rcu(dest, &svc->destinations, n_list) {
w = atomic_read(&dest->weight);
if ((dest->flags & IP_VS_DEST_F_OVERLOAD) ||
atomic_read(&dest->activeconns) > w ||
w == 0)
continue;
if (!h || w > hw) {
h = dest;
hw = w;
}
}
if (h) {
IP_VS_DBG_BUF(6, "OVF: server %s:%u active %d w %d\n",
IP_VS_DBG_ADDR(h->af, &h->addr),
ntohs(h->port),
atomic_read(&h->activeconns),
atomic_read(&h->weight));
return h;
}
ip_vs_scheduler_err(svc, "no destination available");
return NULL;
}
static struct ip_vs_scheduler ip_vs_ovf_scheduler = {
.name = "ovf",
.refcnt = ATOMIC_INIT(0),
.module = THIS_MODULE,
.n_list = LIST_HEAD_INIT(ip_vs_ovf_scheduler.n_list),
.schedule = ip_vs_ovf_schedule,
};
static int __init ip_vs_ovf_init(void)
{
return register_ip_vs_scheduler(&ip_vs_ovf_scheduler);
}
static void __exit ip_vs_ovf_cleanup(void)
{
unregister_ip_vs_scheduler(&ip_vs_ovf_scheduler);
synchronize_rcu();
}
module_init(ip_vs_ovf_init);
module_exit(ip_vs_ovf_cleanup);
MODULE_LICENSE("GPL");