Add the rt linux 4.1.3-rt3 as base

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

diff --git a/kernel/net/netfilter/ipvs/ip_vs_wlc.c b/kernel/net/netfilter/ipvs/ip_vs_wlc.c
new file mode 100644 (file)
index 0000000..6b366fd
--- /dev/null
+++ b/kernel/net/netfilter/ipvs/ip_vs_wlc.c
@@ -0,0 +1,116 @@
+/*
+ * IPVS:        Weighted Least-Connection Scheduling module
+ *
+ * Authors:     Wensong Zhang <wensong@linuxvirtualserver.org>
+ *              Peter Kese <peter.kese@ijs.si>
+ *
+ *              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            :     changed the ip_vs_wlc_schedule to return dest
+ *     Wensong Zhang            :     changed to use the inactconns in scheduling
+ *     Wensong Zhang            :     changed some comestics things for debugging
+ *     Wensong Zhang            :     changed for the d-linked destination list
+ *     Wensong Zhang            :     added the ip_vs_wlc_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>
+
+/*
+ *     Weighted Least Connection scheduling
+ */
+static struct ip_vs_dest *
+ip_vs_wlc_schedule(struct ip_vs_service *svc, const struct sk_buff *skb,
+                  struct ip_vs_iphdr *iph)
+{
+       struct ip_vs_dest *dest, *least;
+       int loh, doh;
+
+       IP_VS_DBG(6, "ip_vs_wlc_schedule(): Scheduling...\n");
+
+       /*
+        * We calculate the load of each dest server as follows:
+        *                (dest overhead) / dest->weight
+        *
+        * Remember -- no floats in kernel mode!!!
+        * The comparison of h1*w2 > h2*w1 is equivalent to that of
+        *                h1/w1 > h2/w2
+        * if every weight is larger than zero.
+        *
+        * The server with weight=0 is quiesced and will not receive any
+        * new connections.
+        */
+
+       list_for_each_entry_rcu(dest, &svc->destinations, n_list) {
+               if (!(dest->flags & IP_VS_DEST_F_OVERLOAD) &&
+                   atomic_read(&dest->weight) > 0) {
+                       least = dest;
+                       loh = ip_vs_dest_conn_overhead(least);
+                       goto nextstage;
+               }
+       }
+       ip_vs_scheduler_err(svc, "no destination available");
+       return NULL;
+
+       /*
+        *    Find the destination with the least load.
+        */
+  nextstage:
+       list_for_each_entry_continue_rcu(dest, &svc->destinations, n_list) {
+               if (dest->flags & IP_VS_DEST_F_OVERLOAD)
+                       continue;
+               doh = ip_vs_dest_conn_overhead(dest);
+               if ((__s64)loh * atomic_read(&dest->weight) >
+                   (__s64)doh * atomic_read(&least->weight)) {
+                       least = dest;
+                       loh = doh;
+               }
+       }
+
+       IP_VS_DBG_BUF(6, "WLC: server %s:%u "
+                     "activeconns %d refcnt %d weight %d overhead %d\n",
+                     IP_VS_DBG_ADDR(least->af, &least->addr),
+                     ntohs(least->port),
+                     atomic_read(&least->activeconns),
+                     atomic_read(&least->refcnt),
+                     atomic_read(&least->weight), loh);
+
+       return least;
+}
+
+
+static struct ip_vs_scheduler ip_vs_wlc_scheduler =
+{
+       .name =                 "wlc",
+       .refcnt =               ATOMIC_INIT(0),
+       .module =               THIS_MODULE,
+       .n_list =               LIST_HEAD_INIT(ip_vs_wlc_scheduler.n_list),
+       .schedule =             ip_vs_wlc_schedule,
+};
+
+
+static int __init ip_vs_wlc_init(void)
+{
+       return register_ip_vs_scheduler(&ip_vs_wlc_scheduler);
+}
+
+static void __exit ip_vs_wlc_cleanup(void)
+{
+       unregister_ip_vs_scheduler(&ip_vs_wlc_scheduler);
+       synchronize_rcu();
+}
+
+module_init(ip_vs_wlc_init);
+module_exit(ip_vs_wlc_cleanup);
+MODULE_LICENSE("GPL");