Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 2 | * IPVS: Locality-Based Least-Connection with Replication scheduler |
| 3 | * |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 4 | * Authors: Wensong Zhang <wensong@gnuchina.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 | * Julian Anastasov : Added the missing (dest->weight>0) |
| 13 | * condition in the ip_vs_dest_set_max. |
| 14 | * |
| 15 | */ |
| 16 | |
| 17 | /* |
| 18 | * The lblc/r algorithm is as follows (pseudo code): |
| 19 | * |
| 20 | * if serverSet[dest_ip] is null then |
| 21 | * n, serverSet[dest_ip] <- {weighted least-conn node}; |
| 22 | * else |
| 23 | * n <- {least-conn (alive) node in serverSet[dest_ip]}; |
| 24 | * if (n is null) OR |
| 25 | * (n.conns>n.weight AND |
| 26 | * there is a node m with m.conns<m.weight/2) then |
| 27 | * n <- {weighted least-conn node}; |
| 28 | * add n to serverSet[dest_ip]; |
| 29 | * if |serverSet[dest_ip]| > 1 AND |
| 30 | * now - serverSet[dest_ip].lastMod > T then |
| 31 | * m <- {most conn node in serverSet[dest_ip]}; |
| 32 | * remove m from serverSet[dest_ip]; |
| 33 | * if serverSet[dest_ip] changed then |
| 34 | * serverSet[dest_ip].lastMod <- now; |
| 35 | * |
| 36 | * return n; |
| 37 | * |
| 38 | */ |
| 39 | |
Arnaldo Carvalho de Melo | 14c8502 | 2005-12-27 02:43:12 -0200 | [diff] [blame] | 40 | #include <linux/ip.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 41 | #include <linux/module.h> |
| 42 | #include <linux/kernel.h> |
Arnaldo Carvalho de Melo | 14c8502 | 2005-12-27 02:43:12 -0200 | [diff] [blame] | 43 | #include <linux/skbuff.h> |
Al Viro | d7fe0f2 | 2006-12-03 23:15:30 -0500 | [diff] [blame] | 44 | #include <linux/jiffies.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 45 | |
| 46 | /* for sysctl */ |
| 47 | #include <linux/fs.h> |
| 48 | #include <linux/sysctl.h> |
Eric W. Biederman | 457c4cb | 2007-09-12 12:01:34 +0200 | [diff] [blame] | 49 | #include <net/net_namespace.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 50 | |
| 51 | #include <net/ip_vs.h> |
| 52 | |
| 53 | |
| 54 | /* |
| 55 | * It is for garbage collection of stale IPVS lblcr entries, |
| 56 | * when the table is full. |
| 57 | */ |
| 58 | #define CHECK_EXPIRE_INTERVAL (60*HZ) |
| 59 | #define ENTRY_TIMEOUT (6*60*HZ) |
| 60 | |
| 61 | /* |
| 62 | * It is for full expiration check. |
| 63 | * When there is no partial expiration check (garbage collection) |
| 64 | * in a half hour, do a full expiration check to collect stale |
| 65 | * entries that haven't been touched for a day. |
| 66 | */ |
| 67 | #define COUNT_FOR_FULL_EXPIRATION 30 |
| 68 | static int sysctl_ip_vs_lblcr_expiration = 24*60*60*HZ; |
| 69 | |
| 70 | |
| 71 | /* |
| 72 | * for IPVS lblcr entry hash table |
| 73 | */ |
| 74 | #ifndef CONFIG_IP_VS_LBLCR_TAB_BITS |
| 75 | #define CONFIG_IP_VS_LBLCR_TAB_BITS 10 |
| 76 | #endif |
| 77 | #define IP_VS_LBLCR_TAB_BITS CONFIG_IP_VS_LBLCR_TAB_BITS |
| 78 | #define IP_VS_LBLCR_TAB_SIZE (1 << IP_VS_LBLCR_TAB_BITS) |
| 79 | #define IP_VS_LBLCR_TAB_MASK (IP_VS_LBLCR_TAB_SIZE - 1) |
| 80 | |
| 81 | |
| 82 | /* |
| 83 | * IPVS destination set structure and operations |
| 84 | */ |
| 85 | struct ip_vs_dest_list { |
| 86 | struct ip_vs_dest_list *next; /* list link */ |
| 87 | struct ip_vs_dest *dest; /* destination server */ |
| 88 | }; |
| 89 | |
| 90 | struct ip_vs_dest_set { |
| 91 | atomic_t size; /* set size */ |
| 92 | unsigned long lastmod; /* last modified time */ |
| 93 | struct ip_vs_dest_list *list; /* destination list */ |
| 94 | rwlock_t lock; /* lock for this list */ |
| 95 | }; |
| 96 | |
| 97 | |
| 98 | static struct ip_vs_dest_list * |
| 99 | ip_vs_dest_set_insert(struct ip_vs_dest_set *set, struct ip_vs_dest *dest) |
| 100 | { |
| 101 | struct ip_vs_dest_list *e; |
| 102 | |
| 103 | for (e=set->list; e!=NULL; e=e->next) { |
| 104 | if (e->dest == dest) |
| 105 | /* already existed */ |
| 106 | return NULL; |
| 107 | } |
| 108 | |
| 109 | e = kmalloc(sizeof(struct ip_vs_dest_list), GFP_ATOMIC); |
| 110 | if (e == NULL) { |
| 111 | IP_VS_ERR("ip_vs_dest_set_insert(): no memory\n"); |
| 112 | return NULL; |
| 113 | } |
| 114 | |
| 115 | atomic_inc(&dest->refcnt); |
| 116 | e->dest = dest; |
| 117 | |
| 118 | /* link it to the list */ |
| 119 | write_lock(&set->lock); |
| 120 | e->next = set->list; |
| 121 | set->list = e; |
| 122 | atomic_inc(&set->size); |
| 123 | write_unlock(&set->lock); |
| 124 | |
| 125 | set->lastmod = jiffies; |
| 126 | return e; |
| 127 | } |
| 128 | |
| 129 | static void |
| 130 | ip_vs_dest_set_erase(struct ip_vs_dest_set *set, struct ip_vs_dest *dest) |
| 131 | { |
| 132 | struct ip_vs_dest_list *e, **ep; |
| 133 | |
| 134 | write_lock(&set->lock); |
| 135 | for (ep=&set->list, e=*ep; e!=NULL; e=*ep) { |
| 136 | if (e->dest == dest) { |
| 137 | /* HIT */ |
| 138 | *ep = e->next; |
| 139 | atomic_dec(&set->size); |
| 140 | set->lastmod = jiffies; |
| 141 | atomic_dec(&e->dest->refcnt); |
| 142 | kfree(e); |
| 143 | break; |
| 144 | } |
| 145 | ep = &e->next; |
| 146 | } |
| 147 | write_unlock(&set->lock); |
| 148 | } |
| 149 | |
| 150 | static void ip_vs_dest_set_eraseall(struct ip_vs_dest_set *set) |
| 151 | { |
| 152 | struct ip_vs_dest_list *e, **ep; |
| 153 | |
| 154 | write_lock(&set->lock); |
| 155 | for (ep=&set->list, e=*ep; e!=NULL; e=*ep) { |
| 156 | *ep = e->next; |
| 157 | /* |
| 158 | * We don't kfree dest because it is refered either |
| 159 | * by its service or by the trash dest list. |
| 160 | */ |
| 161 | atomic_dec(&e->dest->refcnt); |
| 162 | kfree(e); |
| 163 | } |
| 164 | write_unlock(&set->lock); |
| 165 | } |
| 166 | |
| 167 | /* get weighted least-connection node in the destination set */ |
| 168 | static inline struct ip_vs_dest *ip_vs_dest_set_min(struct ip_vs_dest_set *set) |
| 169 | { |
| 170 | register struct ip_vs_dest_list *e; |
| 171 | struct ip_vs_dest *dest, *least; |
| 172 | int loh, doh; |
| 173 | |
| 174 | if (set == NULL) |
| 175 | return NULL; |
| 176 | |
| 177 | read_lock(&set->lock); |
| 178 | /* select the first destination server, whose weight > 0 */ |
| 179 | for (e=set->list; e!=NULL; e=e->next) { |
| 180 | least = e->dest; |
| 181 | if (least->flags & IP_VS_DEST_F_OVERLOAD) |
| 182 | continue; |
| 183 | |
| 184 | if ((atomic_read(&least->weight) > 0) |
| 185 | && (least->flags & IP_VS_DEST_F_AVAILABLE)) { |
| 186 | loh = atomic_read(&least->activeconns) * 50 |
| 187 | + atomic_read(&least->inactconns); |
| 188 | goto nextstage; |
| 189 | } |
| 190 | } |
| 191 | read_unlock(&set->lock); |
| 192 | return NULL; |
| 193 | |
| 194 | /* find the destination with the weighted least load */ |
| 195 | nextstage: |
| 196 | for (e=e->next; e!=NULL; e=e->next) { |
| 197 | dest = e->dest; |
| 198 | if (dest->flags & IP_VS_DEST_F_OVERLOAD) |
| 199 | continue; |
| 200 | |
| 201 | doh = atomic_read(&dest->activeconns) * 50 |
| 202 | + atomic_read(&dest->inactconns); |
| 203 | if ((loh * atomic_read(&dest->weight) > |
| 204 | doh * atomic_read(&least->weight)) |
| 205 | && (dest->flags & IP_VS_DEST_F_AVAILABLE)) { |
| 206 | least = dest; |
| 207 | loh = doh; |
| 208 | } |
| 209 | } |
| 210 | read_unlock(&set->lock); |
| 211 | |
| 212 | IP_VS_DBG(6, "ip_vs_dest_set_min: server %d.%d.%d.%d:%d " |
| 213 | "activeconns %d refcnt %d weight %d overhead %d\n", |
| 214 | NIPQUAD(least->addr), ntohs(least->port), |
| 215 | atomic_read(&least->activeconns), |
| 216 | atomic_read(&least->refcnt), |
| 217 | atomic_read(&least->weight), loh); |
| 218 | return least; |
| 219 | } |
| 220 | |
| 221 | |
| 222 | /* get weighted most-connection node in the destination set */ |
| 223 | static inline struct ip_vs_dest *ip_vs_dest_set_max(struct ip_vs_dest_set *set) |
| 224 | { |
| 225 | register struct ip_vs_dest_list *e; |
| 226 | struct ip_vs_dest *dest, *most; |
| 227 | int moh, doh; |
| 228 | |
| 229 | if (set == NULL) |
| 230 | return NULL; |
| 231 | |
| 232 | read_lock(&set->lock); |
| 233 | /* select the first destination server, whose weight > 0 */ |
| 234 | for (e=set->list; e!=NULL; e=e->next) { |
| 235 | most = e->dest; |
| 236 | if (atomic_read(&most->weight) > 0) { |
| 237 | moh = atomic_read(&most->activeconns) * 50 |
| 238 | + atomic_read(&most->inactconns); |
| 239 | goto nextstage; |
| 240 | } |
| 241 | } |
| 242 | read_unlock(&set->lock); |
| 243 | return NULL; |
| 244 | |
| 245 | /* find the destination with the weighted most load */ |
| 246 | nextstage: |
| 247 | for (e=e->next; e!=NULL; e=e->next) { |
| 248 | dest = e->dest; |
| 249 | doh = atomic_read(&dest->activeconns) * 50 |
| 250 | + atomic_read(&dest->inactconns); |
| 251 | /* moh/mw < doh/dw ==> moh*dw < doh*mw, where mw,dw>0 */ |
| 252 | if ((moh * atomic_read(&dest->weight) < |
| 253 | doh * atomic_read(&most->weight)) |
| 254 | && (atomic_read(&dest->weight) > 0)) { |
| 255 | most = dest; |
| 256 | moh = doh; |
| 257 | } |
| 258 | } |
| 259 | read_unlock(&set->lock); |
| 260 | |
| 261 | IP_VS_DBG(6, "ip_vs_dest_set_max: server %d.%d.%d.%d:%d " |
| 262 | "activeconns %d refcnt %d weight %d overhead %d\n", |
| 263 | NIPQUAD(most->addr), ntohs(most->port), |
| 264 | atomic_read(&most->activeconns), |
| 265 | atomic_read(&most->refcnt), |
| 266 | atomic_read(&most->weight), moh); |
| 267 | return most; |
| 268 | } |
| 269 | |
| 270 | |
| 271 | /* |
| 272 | * IPVS lblcr entry represents an association between destination |
| 273 | * IP address and its destination server set |
| 274 | */ |
| 275 | struct ip_vs_lblcr_entry { |
| 276 | struct list_head list; |
Al Viro | 014d730 | 2006-09-28 14:29:52 -0700 | [diff] [blame] | 277 | __be32 addr; /* destination IP address */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 278 | struct ip_vs_dest_set set; /* destination server set */ |
| 279 | unsigned long lastuse; /* last used time */ |
| 280 | }; |
| 281 | |
| 282 | |
| 283 | /* |
| 284 | * IPVS lblcr hash table |
| 285 | */ |
| 286 | struct ip_vs_lblcr_table { |
| 287 | rwlock_t lock; /* lock for this table */ |
| 288 | struct list_head bucket[IP_VS_LBLCR_TAB_SIZE]; /* hash bucket */ |
| 289 | atomic_t entries; /* number of entries */ |
| 290 | int max_size; /* maximum size of entries */ |
| 291 | struct timer_list periodic_timer; /* collect stale entries */ |
| 292 | int rover; /* rover for expire check */ |
| 293 | int counter; /* counter for no expire */ |
| 294 | }; |
| 295 | |
| 296 | |
| 297 | /* |
| 298 | * IPVS LBLCR sysctl table |
| 299 | */ |
| 300 | |
| 301 | static ctl_table vs_vars_table[] = { |
| 302 | { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 303 | .procname = "lblcr_expiration", |
| 304 | .data = &sysctl_ip_vs_lblcr_expiration, |
| 305 | .maxlen = sizeof(int), |
YOSHIFUJI Hideaki | e905a9e | 2007-02-09 23:24:47 +0900 | [diff] [blame] | 306 | .mode = 0644, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 307 | .proc_handler = &proc_dointvec_jiffies, |
| 308 | }, |
| 309 | { .ctl_name = 0 } |
| 310 | }; |
| 311 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 312 | static struct ctl_table_header * sysctl_header; |
| 313 | |
| 314 | /* |
| 315 | * new/free a ip_vs_lblcr_entry, which is a mapping of a destination |
| 316 | * IP address to a server. |
| 317 | */ |
Al Viro | 014d730 | 2006-09-28 14:29:52 -0700 | [diff] [blame] | 318 | static inline struct ip_vs_lblcr_entry *ip_vs_lblcr_new(__be32 daddr) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 319 | { |
| 320 | struct ip_vs_lblcr_entry *en; |
| 321 | |
| 322 | en = kmalloc(sizeof(struct ip_vs_lblcr_entry), GFP_ATOMIC); |
| 323 | if (en == NULL) { |
| 324 | IP_VS_ERR("ip_vs_lblcr_new(): no memory\n"); |
| 325 | return NULL; |
| 326 | } |
| 327 | |
| 328 | INIT_LIST_HEAD(&en->list); |
| 329 | en->addr = daddr; |
| 330 | |
| 331 | /* initilize its dest set */ |
| 332 | atomic_set(&(en->set.size), 0); |
| 333 | en->set.list = NULL; |
| 334 | rwlock_init(&en->set.lock); |
| 335 | |
| 336 | return en; |
| 337 | } |
| 338 | |
| 339 | |
| 340 | static inline void ip_vs_lblcr_free(struct ip_vs_lblcr_entry *en) |
| 341 | { |
| 342 | list_del(&en->list); |
| 343 | ip_vs_dest_set_eraseall(&en->set); |
| 344 | kfree(en); |
| 345 | } |
| 346 | |
| 347 | |
| 348 | /* |
| 349 | * Returns hash value for IPVS LBLCR entry |
| 350 | */ |
Al Viro | 014d730 | 2006-09-28 14:29:52 -0700 | [diff] [blame] | 351 | static inline unsigned ip_vs_lblcr_hashkey(__be32 addr) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 352 | { |
| 353 | return (ntohl(addr)*2654435761UL) & IP_VS_LBLCR_TAB_MASK; |
| 354 | } |
| 355 | |
| 356 | |
| 357 | /* |
| 358 | * Hash an entry in the ip_vs_lblcr_table. |
| 359 | * returns bool success. |
| 360 | */ |
| 361 | static int |
| 362 | ip_vs_lblcr_hash(struct ip_vs_lblcr_table *tbl, struct ip_vs_lblcr_entry *en) |
| 363 | { |
| 364 | unsigned hash; |
| 365 | |
| 366 | if (!list_empty(&en->list)) { |
| 367 | IP_VS_ERR("ip_vs_lblcr_hash(): request for already hashed, " |
| 368 | "called from %p\n", __builtin_return_address(0)); |
| 369 | return 0; |
| 370 | } |
| 371 | |
| 372 | /* |
| 373 | * Hash by destination IP address |
| 374 | */ |
| 375 | hash = ip_vs_lblcr_hashkey(en->addr); |
| 376 | |
| 377 | write_lock(&tbl->lock); |
| 378 | list_add(&en->list, &tbl->bucket[hash]); |
| 379 | atomic_inc(&tbl->entries); |
| 380 | write_unlock(&tbl->lock); |
| 381 | |
| 382 | return 1; |
| 383 | } |
| 384 | |
| 385 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 386 | /* |
| 387 | * Get ip_vs_lblcr_entry associated with supplied parameters. |
| 388 | */ |
| 389 | static inline struct ip_vs_lblcr_entry * |
Al Viro | 014d730 | 2006-09-28 14:29:52 -0700 | [diff] [blame] | 390 | ip_vs_lblcr_get(struct ip_vs_lblcr_table *tbl, __be32 addr) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 391 | { |
| 392 | unsigned hash; |
| 393 | struct ip_vs_lblcr_entry *en; |
| 394 | |
| 395 | hash = ip_vs_lblcr_hashkey(addr); |
| 396 | |
| 397 | read_lock(&tbl->lock); |
| 398 | |
| 399 | list_for_each_entry(en, &tbl->bucket[hash], list) { |
| 400 | if (en->addr == addr) { |
| 401 | /* HIT */ |
| 402 | read_unlock(&tbl->lock); |
| 403 | return en; |
| 404 | } |
| 405 | } |
| 406 | |
| 407 | read_unlock(&tbl->lock); |
| 408 | |
| 409 | return NULL; |
| 410 | } |
| 411 | |
| 412 | |
| 413 | /* |
| 414 | * Flush all the entries of the specified table. |
| 415 | */ |
| 416 | static void ip_vs_lblcr_flush(struct ip_vs_lblcr_table *tbl) |
| 417 | { |
| 418 | int i; |
| 419 | struct ip_vs_lblcr_entry *en, *nxt; |
| 420 | |
| 421 | for (i=0; i<IP_VS_LBLCR_TAB_SIZE; i++) { |
| 422 | write_lock(&tbl->lock); |
| 423 | list_for_each_entry_safe(en, nxt, &tbl->bucket[i], list) { |
| 424 | ip_vs_lblcr_free(en); |
| 425 | atomic_dec(&tbl->entries); |
| 426 | } |
| 427 | write_unlock(&tbl->lock); |
| 428 | } |
| 429 | } |
| 430 | |
| 431 | |
| 432 | static inline void ip_vs_lblcr_full_check(struct ip_vs_lblcr_table *tbl) |
| 433 | { |
| 434 | unsigned long now = jiffies; |
| 435 | int i, j; |
| 436 | struct ip_vs_lblcr_entry *en, *nxt; |
| 437 | |
| 438 | for (i=0, j=tbl->rover; i<IP_VS_LBLCR_TAB_SIZE; i++) { |
| 439 | j = (j + 1) & IP_VS_LBLCR_TAB_MASK; |
| 440 | |
| 441 | write_lock(&tbl->lock); |
| 442 | list_for_each_entry_safe(en, nxt, &tbl->bucket[j], list) { |
| 443 | if (time_after(en->lastuse+sysctl_ip_vs_lblcr_expiration, |
| 444 | now)) |
| 445 | continue; |
| 446 | |
| 447 | ip_vs_lblcr_free(en); |
| 448 | atomic_dec(&tbl->entries); |
| 449 | } |
| 450 | write_unlock(&tbl->lock); |
| 451 | } |
| 452 | tbl->rover = j; |
| 453 | } |
| 454 | |
| 455 | |
| 456 | /* |
| 457 | * Periodical timer handler for IPVS lblcr table |
| 458 | * It is used to collect stale entries when the number of entries |
| 459 | * exceeds the maximum size of the table. |
| 460 | * |
| 461 | * Fixme: we probably need more complicated algorithm to collect |
| 462 | * entries that have not been used for a long time even |
| 463 | * if the number of entries doesn't exceed the maximum size |
| 464 | * of the table. |
| 465 | * The full expiration check is for this purpose now. |
| 466 | */ |
| 467 | static void ip_vs_lblcr_check_expire(unsigned long data) |
| 468 | { |
| 469 | struct ip_vs_lblcr_table *tbl; |
| 470 | unsigned long now = jiffies; |
| 471 | int goal; |
| 472 | int i, j; |
| 473 | struct ip_vs_lblcr_entry *en, *nxt; |
| 474 | |
| 475 | tbl = (struct ip_vs_lblcr_table *)data; |
| 476 | |
| 477 | if ((tbl->counter % COUNT_FOR_FULL_EXPIRATION) == 0) { |
| 478 | /* do full expiration check */ |
| 479 | ip_vs_lblcr_full_check(tbl); |
| 480 | tbl->counter = 1; |
| 481 | goto out; |
| 482 | } |
| 483 | |
| 484 | if (atomic_read(&tbl->entries) <= tbl->max_size) { |
| 485 | tbl->counter++; |
| 486 | goto out; |
| 487 | } |
| 488 | |
| 489 | goal = (atomic_read(&tbl->entries) - tbl->max_size)*4/3; |
| 490 | if (goal > tbl->max_size/2) |
| 491 | goal = tbl->max_size/2; |
| 492 | |
| 493 | for (i=0, j=tbl->rover; i<IP_VS_LBLCR_TAB_SIZE; i++) { |
| 494 | j = (j + 1) & IP_VS_LBLCR_TAB_MASK; |
| 495 | |
| 496 | write_lock(&tbl->lock); |
| 497 | list_for_each_entry_safe(en, nxt, &tbl->bucket[j], list) { |
| 498 | if (time_before(now, en->lastuse+ENTRY_TIMEOUT)) |
| 499 | continue; |
| 500 | |
| 501 | ip_vs_lblcr_free(en); |
| 502 | atomic_dec(&tbl->entries); |
| 503 | goal--; |
| 504 | } |
| 505 | write_unlock(&tbl->lock); |
| 506 | if (goal <= 0) |
| 507 | break; |
| 508 | } |
| 509 | tbl->rover = j; |
| 510 | |
| 511 | out: |
| 512 | mod_timer(&tbl->periodic_timer, jiffies+CHECK_EXPIRE_INTERVAL); |
| 513 | } |
| 514 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 515 | static int ip_vs_lblcr_init_svc(struct ip_vs_service *svc) |
| 516 | { |
| 517 | int i; |
| 518 | struct ip_vs_lblcr_table *tbl; |
| 519 | |
| 520 | /* |
| 521 | * Allocate the ip_vs_lblcr_table for this service |
| 522 | */ |
| 523 | tbl = kmalloc(sizeof(struct ip_vs_lblcr_table), GFP_ATOMIC); |
| 524 | if (tbl == NULL) { |
| 525 | IP_VS_ERR("ip_vs_lblcr_init_svc(): no memory\n"); |
| 526 | return -ENOMEM; |
| 527 | } |
| 528 | svc->sched_data = tbl; |
| 529 | IP_VS_DBG(6, "LBLCR hash table (memory=%Zdbytes) allocated for " |
| 530 | "current service\n", |
| 531 | sizeof(struct ip_vs_lblcr_table)); |
| 532 | |
| 533 | /* |
| 534 | * Initialize the hash buckets |
| 535 | */ |
| 536 | for (i=0; i<IP_VS_LBLCR_TAB_SIZE; i++) { |
| 537 | INIT_LIST_HEAD(&tbl->bucket[i]); |
| 538 | } |
| 539 | rwlock_init(&tbl->lock); |
| 540 | tbl->max_size = IP_VS_LBLCR_TAB_SIZE*16; |
| 541 | tbl->rover = 0; |
| 542 | tbl->counter = 1; |
| 543 | |
| 544 | /* |
| 545 | * Hook periodic timer for garbage collection |
| 546 | */ |
Pavel Emelyanov | b24b8a2 | 2008-01-23 21:20:07 -0800 | [diff] [blame] | 547 | setup_timer(&tbl->periodic_timer, ip_vs_lblcr_check_expire, |
| 548 | (unsigned long)tbl); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 549 | tbl->periodic_timer.expires = jiffies+CHECK_EXPIRE_INTERVAL; |
| 550 | add_timer(&tbl->periodic_timer); |
| 551 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 552 | return 0; |
| 553 | } |
| 554 | |
| 555 | |
| 556 | static int ip_vs_lblcr_done_svc(struct ip_vs_service *svc) |
| 557 | { |
| 558 | struct ip_vs_lblcr_table *tbl = svc->sched_data; |
| 559 | |
| 560 | /* remove periodic timer */ |
| 561 | del_timer_sync(&tbl->periodic_timer); |
| 562 | |
| 563 | /* got to clean up table entries here */ |
| 564 | ip_vs_lblcr_flush(tbl); |
| 565 | |
| 566 | /* release the table itself */ |
| 567 | kfree(svc->sched_data); |
| 568 | IP_VS_DBG(6, "LBLCR hash table (memory=%Zdbytes) released\n", |
| 569 | sizeof(struct ip_vs_lblcr_table)); |
| 570 | |
| 571 | return 0; |
| 572 | } |
| 573 | |
| 574 | |
| 575 | static int ip_vs_lblcr_update_svc(struct ip_vs_service *svc) |
| 576 | { |
| 577 | return 0; |
| 578 | } |
| 579 | |
| 580 | |
| 581 | static inline struct ip_vs_dest * |
| 582 | __ip_vs_wlc_schedule(struct ip_vs_service *svc, struct iphdr *iph) |
| 583 | { |
| 584 | struct ip_vs_dest *dest, *least; |
| 585 | int loh, doh; |
| 586 | |
| 587 | /* |
| 588 | * We think the overhead of processing active connections is fifty |
| 589 | * times higher than that of inactive connections in average. (This |
| 590 | * fifty times might not be accurate, we will change it later.) We |
| 591 | * use the following formula to estimate the overhead: |
| 592 | * dest->activeconns*50 + dest->inactconns |
| 593 | * and the load: |
| 594 | * (dest overhead) / dest->weight |
| 595 | * |
| 596 | * Remember -- no floats in kernel mode!!! |
| 597 | * The comparison of h1*w2 > h2*w1 is equivalent to that of |
| 598 | * h1/w1 > h2/w2 |
| 599 | * if every weight is larger than zero. |
| 600 | * |
| 601 | * The server with weight=0 is quiesced and will not receive any |
| 602 | * new connection. |
| 603 | */ |
| 604 | list_for_each_entry(dest, &svc->destinations, n_list) { |
| 605 | if (dest->flags & IP_VS_DEST_F_OVERLOAD) |
| 606 | continue; |
| 607 | |
| 608 | if (atomic_read(&dest->weight) > 0) { |
| 609 | least = dest; |
| 610 | loh = atomic_read(&least->activeconns) * 50 |
| 611 | + atomic_read(&least->inactconns); |
| 612 | goto nextstage; |
| 613 | } |
| 614 | } |
| 615 | return NULL; |
| 616 | |
| 617 | /* |
| 618 | * Find the destination with the least load. |
| 619 | */ |
| 620 | nextstage: |
| 621 | list_for_each_entry_continue(dest, &svc->destinations, n_list) { |
| 622 | if (dest->flags & IP_VS_DEST_F_OVERLOAD) |
| 623 | continue; |
| 624 | |
| 625 | doh = atomic_read(&dest->activeconns) * 50 |
| 626 | + atomic_read(&dest->inactconns); |
| 627 | if (loh * atomic_read(&dest->weight) > |
| 628 | doh * atomic_read(&least->weight)) { |
| 629 | least = dest; |
| 630 | loh = doh; |
| 631 | } |
| 632 | } |
| 633 | |
| 634 | IP_VS_DBG(6, "LBLCR: server %d.%d.%d.%d:%d " |
| 635 | "activeconns %d refcnt %d weight %d overhead %d\n", |
| 636 | NIPQUAD(least->addr), ntohs(least->port), |
| 637 | atomic_read(&least->activeconns), |
| 638 | atomic_read(&least->refcnt), |
| 639 | atomic_read(&least->weight), loh); |
| 640 | |
| 641 | return least; |
| 642 | } |
| 643 | |
| 644 | |
| 645 | /* |
| 646 | * If this destination server is overloaded and there is a less loaded |
| 647 | * server, then return true. |
| 648 | */ |
| 649 | static inline int |
| 650 | is_overloaded(struct ip_vs_dest *dest, struct ip_vs_service *svc) |
| 651 | { |
| 652 | if (atomic_read(&dest->activeconns) > atomic_read(&dest->weight)) { |
| 653 | struct ip_vs_dest *d; |
| 654 | |
| 655 | list_for_each_entry(d, &svc->destinations, n_list) { |
| 656 | if (atomic_read(&d->activeconns)*2 |
| 657 | < atomic_read(&d->weight)) { |
| 658 | return 1; |
| 659 | } |
| 660 | } |
| 661 | } |
| 662 | return 0; |
| 663 | } |
| 664 | |
| 665 | |
| 666 | /* |
| 667 | * Locality-Based (weighted) Least-Connection scheduling |
| 668 | */ |
| 669 | static struct ip_vs_dest * |
| 670 | ip_vs_lblcr_schedule(struct ip_vs_service *svc, const struct sk_buff *skb) |
| 671 | { |
| 672 | struct ip_vs_dest *dest; |
| 673 | struct ip_vs_lblcr_table *tbl; |
| 674 | struct ip_vs_lblcr_entry *en; |
Arnaldo Carvalho de Melo | eddc9ec | 2007-04-20 22:47:35 -0700 | [diff] [blame] | 675 | struct iphdr *iph = ip_hdr(skb); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 676 | |
| 677 | IP_VS_DBG(6, "ip_vs_lblcr_schedule(): Scheduling...\n"); |
| 678 | |
| 679 | tbl = (struct ip_vs_lblcr_table *)svc->sched_data; |
| 680 | en = ip_vs_lblcr_get(tbl, iph->daddr); |
| 681 | if (en == NULL) { |
| 682 | dest = __ip_vs_wlc_schedule(svc, iph); |
| 683 | if (dest == NULL) { |
| 684 | IP_VS_DBG(1, "no destination available\n"); |
| 685 | return NULL; |
| 686 | } |
| 687 | en = ip_vs_lblcr_new(iph->daddr); |
| 688 | if (en == NULL) { |
| 689 | return NULL; |
| 690 | } |
| 691 | ip_vs_dest_set_insert(&en->set, dest); |
| 692 | ip_vs_lblcr_hash(tbl, en); |
| 693 | } else { |
| 694 | dest = ip_vs_dest_set_min(&en->set); |
| 695 | if (!dest || is_overloaded(dest, svc)) { |
| 696 | dest = __ip_vs_wlc_schedule(svc, iph); |
| 697 | if (dest == NULL) { |
| 698 | IP_VS_DBG(1, "no destination available\n"); |
| 699 | return NULL; |
| 700 | } |
| 701 | ip_vs_dest_set_insert(&en->set, dest); |
| 702 | } |
| 703 | if (atomic_read(&en->set.size) > 1 && |
| 704 | jiffies-en->set.lastmod > sysctl_ip_vs_lblcr_expiration) { |
| 705 | struct ip_vs_dest *m; |
| 706 | m = ip_vs_dest_set_max(&en->set); |
| 707 | if (m) |
| 708 | ip_vs_dest_set_erase(&en->set, m); |
| 709 | } |
| 710 | } |
| 711 | en->lastuse = jiffies; |
| 712 | |
| 713 | IP_VS_DBG(6, "LBLCR: destination IP address %u.%u.%u.%u " |
| 714 | "--> server %u.%u.%u.%u:%d\n", |
| 715 | NIPQUAD(en->addr), |
| 716 | NIPQUAD(dest->addr), |
| 717 | ntohs(dest->port)); |
| 718 | |
| 719 | return dest; |
| 720 | } |
| 721 | |
| 722 | |
| 723 | /* |
| 724 | * IPVS LBLCR Scheduler structure |
| 725 | */ |
| 726 | static struct ip_vs_scheduler ip_vs_lblcr_scheduler = |
| 727 | { |
| 728 | .name = "lblcr", |
| 729 | .refcnt = ATOMIC_INIT(0), |
| 730 | .module = THIS_MODULE, |
| 731 | .init_service = ip_vs_lblcr_init_svc, |
| 732 | .done_service = ip_vs_lblcr_done_svc, |
| 733 | .update_service = ip_vs_lblcr_update_svc, |
| 734 | .schedule = ip_vs_lblcr_schedule, |
| 735 | }; |
| 736 | |
| 737 | |
| 738 | static int __init ip_vs_lblcr_init(void) |
| 739 | { |
Pavel Emelyanov | a014bc8 | 2007-12-04 00:43:24 -0800 | [diff] [blame] | 740 | int ret; |
| 741 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 742 | INIT_LIST_HEAD(&ip_vs_lblcr_scheduler.n_list); |
Pavel Emelyanov | 90754f8 | 2008-01-12 02:33:50 -0800 | [diff] [blame] | 743 | sysctl_header = register_sysctl_paths(net_vs_ctl_path, vs_vars_table); |
Pavel Emelyanov | a014bc8 | 2007-12-04 00:43:24 -0800 | [diff] [blame] | 744 | ret = register_ip_vs_scheduler(&ip_vs_lblcr_scheduler); |
| 745 | if (ret) |
| 746 | unregister_sysctl_table(sysctl_header); |
| 747 | return ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 748 | } |
| 749 | |
| 750 | |
| 751 | static void __exit ip_vs_lblcr_cleanup(void) |
| 752 | { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 753 | unregister_sysctl_table(sysctl_header); |
| 754 | unregister_ip_vs_scheduler(&ip_vs_lblcr_scheduler); |
| 755 | } |
| 756 | |
| 757 | |
| 758 | module_init(ip_vs_lblcr_init); |
| 759 | module_exit(ip_vs_lblcr_cleanup); |
| 760 | MODULE_LICENSE("GPL"); |