projects / deliverable / linux.git / blame
| Commit | Line | Data |
|---|---|---|
| 1da177e4 LT |
1 | /* |
| 2 | * IPVS: Least-Connection Scheduling module | |
| 3 | * | |
| 1da177e4 LT |
4 | * Authors: Wensong Zhang <wensong@linuxvirtualserver.org> |
| 5 | * | |
| 6 | * This program is free software; you can redistribute it and/or | |
| 7 | * modify it under the terms of the GNU General Public License | |
| 8 | * as published by the Free Software Foundation; either version | |
| 9 | * 2 of the License, or (at your option) any later version. | |
| 10 | * | |
| 11 | * Changes: | |
| 12 | * Wensong Zhang : added the ip_vs_lc_update_svc | |
| 13 | * Wensong Zhang : added any dest with weight=0 is quiesced | |
| 14 | * | |
| 15 | */ | |
| 16 | ||
| 9aada7ac HE |
17 | #define KMSG_COMPONENT "IPVS" |
| 18 | #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt | |
| 19 | ||
| 1da177e4 LT |
20 | #include <linux/module.h> |
| 21 | #include <linux/kernel.h> | |
| 22 | ||
| 23 | #include <net/ip_vs.h> | |
| 24 | ||
| 1da177e4 LT |
25 | /* |
| 26 | * Least Connection scheduling | |
| 27 | */ | |
| 28 | static struct ip_vs_dest * | |
| bba54de5 JA |
29 | ip_vs_lc_schedule(struct ip_vs_service *svc, const struct sk_buff *skb, |
| 30 | struct ip_vs_iphdr *iph) | |
| 1da177e4 LT |
31 | { |
| 32 | struct ip_vs_dest *dest, *least = NULL; | |
| 33 | unsigned int loh = 0, doh; | |
| 34 | ||
| 1e3e238e | 35 | IP_VS_DBG(6, "%s(): Scheduling...\n", __func__); |
| 1da177e4 LT |
36 | |
| 37 | /* | |
| 38 | * Simply select the server with the least number of | |
| 39 | * (activeconns<<5) + inactconns | |
| 40 | * Except whose weight is equal to zero. | |
| 41 | * If the weight is equal to zero, it means that the server is | |
| 42 | * quiesced, the existing connections to the server still get | |
| 43 | * served, but no new connection is assigned to the server. | |
| 44 | */ | |
| 45 | ||
| 4ebd288b | 46 | list_for_each_entry_rcu(dest, &svc->destinations, n_list) { |
| 1da177e4 LT |
47 | if ((dest->flags & IP_VS_DEST_F_OVERLOAD) || |
| 48 | atomic_read(&dest->weight) == 0) | |
| 49 | continue; | |
| b552f7e3 | 50 | doh = ip_vs_dest_conn_overhead(dest); |
| 1da177e4 LT |
51 | if (!least || doh < loh) { |
| 52 | least = dest; | |
| 53 | loh = doh; | |
| 54 | } | |
| 55 | } | |
| 56 | ||
| 68888d10 | 57 | if (!least) |
| 41ac51ee | 58 | ip_vs_scheduler_err(svc, "no destination available"); |
| 68888d10 SH |
59 | else |
| 60 | IP_VS_DBG_BUF(6, "LC: server %s:%u activeconns %d " | |
| 61 | "inactconns %d\n", | |
| 4d316f3f | 62 | IP_VS_DBG_ADDR(least->af, &least->addr), |
| 68888d10 SH |
63 | ntohs(least->port), |
| 64 | atomic_read(&least->activeconns), | |
| 65 | atomic_read(&least->inactconns)); | |
| 1da177e4 LT |
66 | |
| 67 | return least; | |
| 68 | } | |
| 69 | ||
| 70 | ||
| 71 | static struct ip_vs_scheduler ip_vs_lc_scheduler = { | |
| 72 | .name = "lc", | |
| 73 | .refcnt = ATOMIC_INIT(0), | |
| 74 | .module = THIS_MODULE, | |
| d149ccc9 | 75 | .n_list = LIST_HEAD_INIT(ip_vs_lc_scheduler.n_list), |
| 1da177e4 LT |
76 | .schedule = ip_vs_lc_schedule, |
| 77 | }; | |
| 78 | ||
| 79 | ||
| 80 | static int __init ip_vs_lc_init(void) | |
| 81 | { | |
| 1da177e4 LT |
82 | return register_ip_vs_scheduler(&ip_vs_lc_scheduler) ; |
| 83 | } | |
| 84 | ||
| 85 | static void __exit ip_vs_lc_cleanup(void) | |
| 86 | { | |
| 87 | unregister_ip_vs_scheduler(&ip_vs_lc_scheduler); | |
| ceec4c38 | 88 | synchronize_rcu(); |
| 1da177e4 LT |
89 | } |
| 90 | ||
| 91 | module_init(ip_vs_lc_init); | |
| 92 | module_exit(ip_vs_lc_cleanup); | |
| 93 | MODULE_LICENSE("GPL"); |