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author | David S. Miller <davem@davemloft.net> | 2008-10-11 12:39:35 -0700 |
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committer | David S. Miller <davem@davemloft.net> | 2008-10-11 12:39:35 -0700 |
commit | 56c5d900dbb8e042bfad035d18433476931d8f93 (patch) | |
tree | 00b793965beeef10db03e0ff021d2d965c410759 /net/ipv4/ipvs/ip_vs_lblc.c | |
parent | 4dd95b63ae25c5cad6986829b5e8788e9faa0330 (diff) | |
parent | ead9d23d803ea3a73766c3cb27bf7563ac8d7266 (diff) | |
download | op-kernel-dev-56c5d900dbb8e042bfad035d18433476931d8f93.zip op-kernel-dev-56c5d900dbb8e042bfad035d18433476931d8f93.tar.gz |
Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/torvalds/linux-2.6
Conflicts:
sound/core/memalloc.c
Diffstat (limited to 'net/ipv4/ipvs/ip_vs_lblc.c')
-rw-r--r-- | net/ipv4/ipvs/ip_vs_lblc.c | 571 |
1 files changed, 0 insertions, 571 deletions
diff --git a/net/ipv4/ipvs/ip_vs_lblc.c b/net/ipv4/ipvs/ip_vs_lblc.c deleted file mode 100644 index 7a6a319..0000000 --- a/net/ipv4/ipvs/ip_vs_lblc.c +++ /dev/null @@ -1,571 +0,0 @@ -/* - * IPVS: Locality-Based Least-Connection scheduling module - * - * Authors: Wensong Zhang <wensong@gnuchina.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: - * Martin Hamilton : fixed the terrible locking bugs - * *lock(tbl->lock) ==> *lock(&tbl->lock) - * Wensong Zhang : fixed the uninitilized tbl->lock bug - * Wensong Zhang : added doing full expiration check to - * collect stale entries of 24+ hours when - * no partial expire check in a half hour - * Julian Anastasov : replaced del_timer call with del_timer_sync - * to avoid the possible race between timer - * handler and del_timer thread in SMP - * - */ - -/* - * The lblc algorithm is as follows (pseudo code): - * - * if cachenode[dest_ip] is null then - * n, cachenode[dest_ip] <- {weighted least-conn node}; - * else - * n <- cachenode[dest_ip]; - * if (n is dead) OR - * (n.conns>n.weight AND - * there is a node m with m.conns<m.weight/2) then - * n, cachenode[dest_ip] <- {weighted least-conn node}; - * - * return n; - * - * Thanks must go to Wenzhuo Zhang for talking WCCP to me and pushing - * me to write this module. - */ - -#include <linux/ip.h> -#include <linux/module.h> -#include <linux/kernel.h> -#include <linux/skbuff.h> -#include <linux/jiffies.h> - -/* for sysctl */ -#include <linux/fs.h> -#include <linux/sysctl.h> - -#include <net/ip_vs.h> - - -/* - * It is for garbage collection of stale IPVS lblc entries, - * when the table is full. - */ -#define CHECK_EXPIRE_INTERVAL (60*HZ) -#define ENTRY_TIMEOUT (6*60*HZ) - -/* - * It is for full expiration check. - * When there is no partial expiration check (garbage collection) - * in a half hour, do a full expiration check to collect stale - * entries that haven't been touched for a day. - */ -#define COUNT_FOR_FULL_EXPIRATION 30 -static int sysctl_ip_vs_lblc_expiration = 24*60*60*HZ; - - -/* - * for IPVS lblc entry hash table - */ -#ifndef CONFIG_IP_VS_LBLC_TAB_BITS -#define CONFIG_IP_VS_LBLC_TAB_BITS 10 -#endif -#define IP_VS_LBLC_TAB_BITS CONFIG_IP_VS_LBLC_TAB_BITS -#define IP_VS_LBLC_TAB_SIZE (1 << IP_VS_LBLC_TAB_BITS) -#define IP_VS_LBLC_TAB_MASK (IP_VS_LBLC_TAB_SIZE - 1) - - -/* - * IPVS lblc entry represents an association between destination - * IP address and its destination server - */ -struct ip_vs_lblc_entry { - struct list_head list; - __be32 addr; /* destination IP address */ - struct ip_vs_dest *dest; /* real server (cache) */ - unsigned long lastuse; /* last used time */ -}; - - -/* - * IPVS lblc hash table - */ -struct ip_vs_lblc_table { - rwlock_t lock; /* lock for this table */ - struct list_head bucket[IP_VS_LBLC_TAB_SIZE]; /* hash bucket */ - atomic_t entries; /* number of entries */ - int max_size; /* maximum size of entries */ - struct timer_list periodic_timer; /* collect stale entries */ - int rover; /* rover for expire check */ - int counter; /* counter for no expire */ -}; - - -/* - * IPVS LBLC sysctl table - */ - -static ctl_table vs_vars_table[] = { - { - .procname = "lblc_expiration", - .data = &sysctl_ip_vs_lblc_expiration, - .maxlen = sizeof(int), - .mode = 0644, - .proc_handler = &proc_dointvec_jiffies, - }, - { .ctl_name = 0 } -}; - -static struct ctl_table_header * sysctl_header; - -/* - * new/free a ip_vs_lblc_entry, which is a mapping of a destionation - * IP address to a server. - */ -static inline struct ip_vs_lblc_entry * -ip_vs_lblc_new(__be32 daddr, struct ip_vs_dest *dest) -{ - struct ip_vs_lblc_entry *en; - - en = kmalloc(sizeof(struct ip_vs_lblc_entry), GFP_ATOMIC); - if (en == NULL) { - IP_VS_ERR("ip_vs_lblc_new(): no memory\n"); - return NULL; - } - - INIT_LIST_HEAD(&en->list); - en->addr = daddr; - - atomic_inc(&dest->refcnt); - en->dest = dest; - - return en; -} - - -static inline void ip_vs_lblc_free(struct ip_vs_lblc_entry *en) -{ - list_del(&en->list); - /* - * We don't kfree dest because it is refered either by its service - * or the trash dest list. - */ - atomic_dec(&en->dest->refcnt); - kfree(en); -} - - -/* - * Returns hash value for IPVS LBLC entry - */ -static inline unsigned ip_vs_lblc_hashkey(__be32 addr) -{ - return (ntohl(addr)*2654435761UL) & IP_VS_LBLC_TAB_MASK; -} - - -/* - * Hash an entry in the ip_vs_lblc_table. - * returns bool success. - */ -static int -ip_vs_lblc_hash(struct ip_vs_lblc_table *tbl, struct ip_vs_lblc_entry *en) -{ - unsigned hash; - - if (!list_empty(&en->list)) { - IP_VS_ERR("ip_vs_lblc_hash(): request for already hashed, " - "called from %p\n", __builtin_return_address(0)); - return 0; - } - - /* - * Hash by destination IP address - */ - hash = ip_vs_lblc_hashkey(en->addr); - - write_lock(&tbl->lock); - list_add(&en->list, &tbl->bucket[hash]); - atomic_inc(&tbl->entries); - write_unlock(&tbl->lock); - - return 1; -} - - -/* - * Get ip_vs_lblc_entry associated with supplied parameters. - */ -static inline struct ip_vs_lblc_entry * -ip_vs_lblc_get(struct ip_vs_lblc_table *tbl, __be32 addr) -{ - unsigned hash; - struct ip_vs_lblc_entry *en; - - hash = ip_vs_lblc_hashkey(addr); - - read_lock(&tbl->lock); - - list_for_each_entry(en, &tbl->bucket[hash], list) { - if (en->addr == addr) { - /* HIT */ - read_unlock(&tbl->lock); - return en; - } - } - - read_unlock(&tbl->lock); - - return NULL; -} - - -/* - * Flush all the entries of the specified table. - */ -static void ip_vs_lblc_flush(struct ip_vs_lblc_table *tbl) -{ - int i; - struct ip_vs_lblc_entry *en, *nxt; - - for (i=0; i<IP_VS_LBLC_TAB_SIZE; i++) { - write_lock(&tbl->lock); - list_for_each_entry_safe(en, nxt, &tbl->bucket[i], list) { - ip_vs_lblc_free(en); - atomic_dec(&tbl->entries); - } - write_unlock(&tbl->lock); - } -} - - -static inline void ip_vs_lblc_full_check(struct ip_vs_lblc_table *tbl) -{ - unsigned long now = jiffies; - int i, j; - struct ip_vs_lblc_entry *en, *nxt; - - for (i=0, j=tbl->rover; i<IP_VS_LBLC_TAB_SIZE; i++) { - j = (j + 1) & IP_VS_LBLC_TAB_MASK; - - write_lock(&tbl->lock); - list_for_each_entry_safe(en, nxt, &tbl->bucket[j], list) { - if (time_before(now, - en->lastuse + sysctl_ip_vs_lblc_expiration)) - continue; - - ip_vs_lblc_free(en); - atomic_dec(&tbl->entries); - } - write_unlock(&tbl->lock); - } - tbl->rover = j; -} - - -/* - * Periodical timer handler for IPVS lblc table - * It is used to collect stale entries when the number of entries - * exceeds the maximum size of the table. - * - * Fixme: we probably need more complicated algorithm to collect - * entries that have not been used for a long time even - * if the number of entries doesn't exceed the maximum size - * of the table. - * The full expiration check is for this purpose now. - */ -static void ip_vs_lblc_check_expire(unsigned long data) -{ - struct ip_vs_lblc_table *tbl; - unsigned long now = jiffies; - int goal; - int i, j; - struct ip_vs_lblc_entry *en, *nxt; - - tbl = (struct ip_vs_lblc_table *)data; - - if ((tbl->counter % COUNT_FOR_FULL_EXPIRATION) == 0) { - /* do full expiration check */ - ip_vs_lblc_full_check(tbl); - tbl->counter = 1; - goto out; - } - - if (atomic_read(&tbl->entries) <= tbl->max_size) { - tbl->counter++; - goto out; - } - - goal = (atomic_read(&tbl->entries) - tbl->max_size)*4/3; - if (goal > tbl->max_size/2) - goal = tbl->max_size/2; - - for (i=0, j=tbl->rover; i<IP_VS_LBLC_TAB_SIZE; i++) { - j = (j + 1) & IP_VS_LBLC_TAB_MASK; - - write_lock(&tbl->lock); - list_for_each_entry_safe(en, nxt, &tbl->bucket[j], list) { - if (time_before(now, en->lastuse + ENTRY_TIMEOUT)) - continue; - - ip_vs_lblc_free(en); - atomic_dec(&tbl->entries); - goal--; - } - write_unlock(&tbl->lock); - if (goal <= 0) - break; - } - tbl->rover = j; - - out: - mod_timer(&tbl->periodic_timer, jiffies+CHECK_EXPIRE_INTERVAL); -} - - -static int ip_vs_lblc_init_svc(struct ip_vs_service *svc) -{ - int i; - struct ip_vs_lblc_table *tbl; - - /* - * Allocate the ip_vs_lblc_table for this service - */ - tbl = kmalloc(sizeof(struct ip_vs_lblc_table), GFP_ATOMIC); - if (tbl == NULL) { - IP_VS_ERR("ip_vs_lblc_init_svc(): no memory\n"); - return -ENOMEM; - } - svc->sched_data = tbl; - IP_VS_DBG(6, "LBLC hash table (memory=%Zdbytes) allocated for " - "current service\n", - sizeof(struct ip_vs_lblc_table)); - - /* - * Initialize the hash buckets - */ - for (i=0; i<IP_VS_LBLC_TAB_SIZE; i++) { - INIT_LIST_HEAD(&tbl->bucket[i]); - } - rwlock_init(&tbl->lock); - tbl->max_size = IP_VS_LBLC_TAB_SIZE*16; - tbl->rover = 0; - tbl->counter = 1; - - /* - * Hook periodic timer for garbage collection - */ - setup_timer(&tbl->periodic_timer, ip_vs_lblc_check_expire, - (unsigned long)tbl); - tbl->periodic_timer.expires = jiffies+CHECK_EXPIRE_INTERVAL; - add_timer(&tbl->periodic_timer); - - return 0; -} - - -static int ip_vs_lblc_done_svc(struct ip_vs_service *svc) -{ - struct ip_vs_lblc_table *tbl = svc->sched_data; - - /* remove periodic timer */ - del_timer_sync(&tbl->periodic_timer); - - /* got to clean up table entries here */ - ip_vs_lblc_flush(tbl); - - /* release the table itself */ - kfree(svc->sched_data); - IP_VS_DBG(6, "LBLC hash table (memory=%Zdbytes) released\n", - sizeof(struct ip_vs_lblc_table)); - - return 0; -} - - -static int ip_vs_lblc_update_svc(struct ip_vs_service *svc) -{ - return 0; -} - - -static inline struct ip_vs_dest * -__ip_vs_wlc_schedule(struct ip_vs_service *svc, struct iphdr *iph) -{ - struct ip_vs_dest *dest, *least; - int loh, doh; - - /* - * We think the overhead of processing active connections is fifty - * times higher than that of inactive connections in average. (This - * fifty times might not be accurate, we will change it later.) We - * use the following formula to estimate the overhead: - * dest->activeconns*50 + dest->inactconns - * and the load: - * (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 connection. - */ - list_for_each_entry(dest, &svc->destinations, n_list) { - if (dest->flags & IP_VS_DEST_F_OVERLOAD) - continue; - if (atomic_read(&dest->weight) > 0) { - least = dest; - loh = atomic_read(&least->activeconns) * 50 - + atomic_read(&least->inactconns); - goto nextstage; - } - } - return NULL; - - /* - * Find the destination with the least load. - */ - nextstage: - list_for_each_entry_continue(dest, &svc->destinations, n_list) { - if (dest->flags & IP_VS_DEST_F_OVERLOAD) - continue; - - doh = atomic_read(&dest->activeconns) * 50 - + atomic_read(&dest->inactconns); - if (loh * atomic_read(&dest->weight) > - doh * atomic_read(&least->weight)) { - least = dest; - loh = doh; - } - } - - IP_VS_DBG(6, "LBLC: server %d.%d.%d.%d:%d " - "activeconns %d refcnt %d weight %d overhead %d\n", - NIPQUAD(least->addr), ntohs(least->port), - atomic_read(&least->activeconns), - atomic_read(&least->refcnt), - atomic_read(&least->weight), loh); - - return least; -} - - -/* - * If this destination server is overloaded and there is a less loaded - * server, then return true. - */ -static inline int -is_overloaded(struct ip_vs_dest *dest, struct ip_vs_service *svc) -{ - if (atomic_read(&dest->activeconns) > atomic_read(&dest->weight)) { - struct ip_vs_dest *d; - - list_for_each_entry(d, &svc->destinations, n_list) { - if (atomic_read(&d->activeconns)*2 - < atomic_read(&d->weight)) { - return 1; - } - } - } - return 0; -} - - -/* - * Locality-Based (weighted) Least-Connection scheduling - */ -static struct ip_vs_dest * -ip_vs_lblc_schedule(struct ip_vs_service *svc, const struct sk_buff *skb) -{ - struct ip_vs_dest *dest; - struct ip_vs_lblc_table *tbl; - struct ip_vs_lblc_entry *en; - struct iphdr *iph = ip_hdr(skb); - - IP_VS_DBG(6, "ip_vs_lblc_schedule(): Scheduling...\n"); - - tbl = (struct ip_vs_lblc_table *)svc->sched_data; - en = ip_vs_lblc_get(tbl, iph->daddr); - if (en == NULL) { - dest = __ip_vs_wlc_schedule(svc, iph); - if (dest == NULL) { - IP_VS_DBG(1, "no destination available\n"); - return NULL; - } - en = ip_vs_lblc_new(iph->daddr, dest); - if (en == NULL) { - return NULL; - } - ip_vs_lblc_hash(tbl, en); - } else { - dest = en->dest; - if (!(dest->flags & IP_VS_DEST_F_AVAILABLE) - || atomic_read(&dest->weight) <= 0 - || is_overloaded(dest, svc)) { - dest = __ip_vs_wlc_schedule(svc, iph); - if (dest == NULL) { - IP_VS_DBG(1, "no destination available\n"); - return NULL; - } - atomic_dec(&en->dest->refcnt); - atomic_inc(&dest->refcnt); - en->dest = dest; - } - } - en->lastuse = jiffies; - - IP_VS_DBG(6, "LBLC: destination IP address %u.%u.%u.%u " - "--> server %u.%u.%u.%u:%d\n", - NIPQUAD(en->addr), - NIPQUAD(dest->addr), - ntohs(dest->port)); - - return dest; -} - - -/* - * IPVS LBLC Scheduler structure - */ -static struct ip_vs_scheduler ip_vs_lblc_scheduler = -{ - .name = "lblc", - .refcnt = ATOMIC_INIT(0), - .module = THIS_MODULE, - .n_list = LIST_HEAD_INIT(ip_vs_lblc_scheduler.n_list), - .init_service = ip_vs_lblc_init_svc, - .done_service = ip_vs_lblc_done_svc, - .update_service = ip_vs_lblc_update_svc, - .schedule = ip_vs_lblc_schedule, -}; - - -static int __init ip_vs_lblc_init(void) -{ - int ret; - - sysctl_header = register_sysctl_paths(net_vs_ctl_path, vs_vars_table); - ret = register_ip_vs_scheduler(&ip_vs_lblc_scheduler); - if (ret) - unregister_sysctl_table(sysctl_header); - return ret; -} - - -static void __exit ip_vs_lblc_cleanup(void) -{ - unregister_sysctl_table(sysctl_header); - unregister_ip_vs_scheduler(&ip_vs_lblc_scheduler); -} - - -module_init(ip_vs_lblc_init); -module_exit(ip_vs_lblc_cleanup); -MODULE_LICENSE("GPL"); |