Add the rt linux 4.1.3-rt3 as base

[kvmfornfv.git] / kernel / net / netfilter / ipvs / ip_vs_lc.c

diff --git a/kernel/net/netfilter/ipvs/ip_vs_lc.c b/kernel/net/netfilter/ipvs/ip_vs_lc.c
new file mode 100644 (file)
index 0000000..19a0769
--- /dev/null
+++ b/kernel/net/netfilter/ipvs/ip_vs_lc.c
@@ -0,0 +1,93 @@
+/*
+ * IPVS:        Least-Connection Scheduling module
+ *
+ * Authors:     Wensong Zhang <wensong@linuxvirtualserver.org>
+ *
+ *              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.
+ *
+ * Changes:
+ *     Wensong Zhang            :     added the ip_vs_lc_update_svc
+ *     Wensong Zhang            :     added any dest with weight=0 is quiesced
+ *
+ */
+
+#define KMSG_COMPONENT "IPVS"
+#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+
+#include <net/ip_vs.h>
+
+/*
+ *     Least Connection scheduling
+ */
+static struct ip_vs_dest *
+ip_vs_lc_schedule(struct ip_vs_service *svc, const struct sk_buff *skb,
+                 struct ip_vs_iphdr *iph)
+{
+       struct ip_vs_dest *dest, *least = NULL;
+       unsigned int loh = 0, doh;
+
+       IP_VS_DBG(6, "%s(): Scheduling...\n", __func__);
+
+       /*
+        * Simply select the server with the least number of
+        *        (activeconns<<5) + inactconns
+        * Except whose weight is equal to zero.
+        * If the weight is equal to zero, it means that the server is
+        * quiesced, the existing connections to the server still get
+        * served, but no new connection is assigned to the server.
+        */
+
+       list_for_each_entry_rcu(dest, &svc->destinations, n_list) {
+               if ((dest->flags & IP_VS_DEST_F_OVERLOAD) ||
+                   atomic_read(&dest->weight) == 0)
+                       continue;
+               doh = ip_vs_dest_conn_overhead(dest);
+               if (!least || doh < loh) {
+                       least = dest;
+                       loh = doh;
+               }
+       }
+
+       if (!least)
+               ip_vs_scheduler_err(svc, "no destination available");
+       else
+               IP_VS_DBG_BUF(6, "LC: server %s:%u activeconns %d "
+                             "inactconns %d\n",
+                             IP_VS_DBG_ADDR(least->af, &least->addr),
+                             ntohs(least->port),
+                             atomic_read(&least->activeconns),
+                             atomic_read(&least->inactconns));
+
+       return least;
+}
+
+
+static struct ip_vs_scheduler ip_vs_lc_scheduler = {
+       .name =                 "lc",
+       .refcnt =               ATOMIC_INIT(0),
+       .module =               THIS_MODULE,
+       .n_list =               LIST_HEAD_INIT(ip_vs_lc_scheduler.n_list),
+       .schedule =             ip_vs_lc_schedule,
+};
+
+
+static int __init ip_vs_lc_init(void)
+{
+       return register_ip_vs_scheduler(&ip_vs_lc_scheduler) ;
+}
+
+static void __exit ip_vs_lc_cleanup(void)
+{
+       unregister_ip_vs_scheduler(&ip_vs_lc_scheduler);
+       synchronize_rcu();
+}
+
+module_init(ip_vs_lc_init);
+module_exit(ip_vs_lc_cleanup);
+MODULE_LICENSE("GPL");