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Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * IPVS: Locality-Based Least-Connection with Replication scheduler | |
3 | * | |
1da177e4 LT |
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 | ||
9aada7ac HE |
40 | #define KMSG_COMPONENT "IPVS" |
41 | #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt | |
42 | ||
14c85021 | 43 | #include <linux/ip.h> |
1da177e4 LT |
44 | #include <linux/module.h> |
45 | #include <linux/kernel.h> | |
14c85021 | 46 | #include <linux/skbuff.h> |
d7fe0f24 | 47 | #include <linux/jiffies.h> |
1da177e4 LT |
48 | |
49 | /* for sysctl */ | |
50 | #include <linux/fs.h> | |
51 | #include <linux/sysctl.h> | |
457c4cbc | 52 | #include <net/net_namespace.h> |
1da177e4 LT |
53 | |
54 | #include <net/ip_vs.h> | |
55 | ||
56 | ||
57 | /* | |
58 | * It is for garbage collection of stale IPVS lblcr entries, | |
59 | * when the table is full. | |
60 | */ | |
61 | #define CHECK_EXPIRE_INTERVAL (60*HZ) | |
62 | #define ENTRY_TIMEOUT (6*60*HZ) | |
63 | ||
64 | /* | |
65 | * It is for full expiration check. | |
66 | * When there is no partial expiration check (garbage collection) | |
67 | * in a half hour, do a full expiration check to collect stale | |
68 | * entries that haven't been touched for a day. | |
69 | */ | |
70 | #define COUNT_FOR_FULL_EXPIRATION 30 | |
71 | static int sysctl_ip_vs_lblcr_expiration = 24*60*60*HZ; | |
72 | ||
73 | ||
74 | /* | |
75 | * for IPVS lblcr entry hash table | |
76 | */ | |
77 | #ifndef CONFIG_IP_VS_LBLCR_TAB_BITS | |
78 | #define CONFIG_IP_VS_LBLCR_TAB_BITS 10 | |
79 | #endif | |
80 | #define IP_VS_LBLCR_TAB_BITS CONFIG_IP_VS_LBLCR_TAB_BITS | |
81 | #define IP_VS_LBLCR_TAB_SIZE (1 << IP_VS_LBLCR_TAB_BITS) | |
82 | #define IP_VS_LBLCR_TAB_MASK (IP_VS_LBLCR_TAB_SIZE - 1) | |
83 | ||
84 | ||
85 | /* | |
86 | * IPVS destination set structure and operations | |
87 | */ | |
88 | struct ip_vs_dest_list { | |
89 | struct ip_vs_dest_list *next; /* list link */ | |
90 | struct ip_vs_dest *dest; /* destination server */ | |
91 | }; | |
92 | ||
93 | struct ip_vs_dest_set { | |
94 | atomic_t size; /* set size */ | |
95 | unsigned long lastmod; /* last modified time */ | |
96 | struct ip_vs_dest_list *list; /* destination list */ | |
97 | rwlock_t lock; /* lock for this list */ | |
98 | }; | |
99 | ||
100 | ||
101 | static struct ip_vs_dest_list * | |
102 | ip_vs_dest_set_insert(struct ip_vs_dest_set *set, struct ip_vs_dest *dest) | |
103 | { | |
104 | struct ip_vs_dest_list *e; | |
105 | ||
106 | for (e=set->list; e!=NULL; e=e->next) { | |
107 | if (e->dest == dest) | |
108 | /* already existed */ | |
109 | return NULL; | |
110 | } | |
111 | ||
f728bafb | 112 | e = kmalloc(sizeof(*e), GFP_ATOMIC); |
1da177e4 | 113 | if (e == NULL) { |
1e3e238e | 114 | pr_err("%s(): no memory\n", __func__); |
1da177e4 LT |
115 | return NULL; |
116 | } | |
117 | ||
118 | atomic_inc(&dest->refcnt); | |
119 | e->dest = dest; | |
120 | ||
121 | /* link it to the list */ | |
1da177e4 LT |
122 | e->next = set->list; |
123 | set->list = e; | |
124 | atomic_inc(&set->size); | |
1da177e4 LT |
125 | |
126 | set->lastmod = jiffies; | |
127 | return e; | |
128 | } | |
129 | ||
130 | static void | |
131 | ip_vs_dest_set_erase(struct ip_vs_dest_set *set, struct ip_vs_dest *dest) | |
132 | { | |
133 | struct ip_vs_dest_list *e, **ep; | |
134 | ||
1da177e4 LT |
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 | } | |
1da177e4 LT |
147 | } |
148 | ||
149 | static void ip_vs_dest_set_eraseall(struct ip_vs_dest_set *set) | |
150 | { | |
151 | struct ip_vs_dest_list *e, **ep; | |
152 | ||
153 | write_lock(&set->lock); | |
154 | for (ep=&set->list, e=*ep; e!=NULL; e=*ep) { | |
155 | *ep = e->next; | |
156 | /* | |
157 | * We don't kfree dest because it is refered either | |
158 | * by its service or by the trash dest list. | |
159 | */ | |
160 | atomic_dec(&e->dest->refcnt); | |
161 | kfree(e); | |
162 | } | |
163 | write_unlock(&set->lock); | |
164 | } | |
165 | ||
166 | /* get weighted least-connection node in the destination set */ | |
167 | static inline struct ip_vs_dest *ip_vs_dest_set_min(struct ip_vs_dest_set *set) | |
168 | { | |
169 | register struct ip_vs_dest_list *e; | |
170 | struct ip_vs_dest *dest, *least; | |
171 | int loh, doh; | |
172 | ||
173 | if (set == NULL) | |
174 | return NULL; | |
175 | ||
1da177e4 LT |
176 | /* select the first destination server, whose weight > 0 */ |
177 | for (e=set->list; e!=NULL; e=e->next) { | |
178 | least = e->dest; | |
179 | if (least->flags & IP_VS_DEST_F_OVERLOAD) | |
180 | continue; | |
181 | ||
182 | if ((atomic_read(&least->weight) > 0) | |
183 | && (least->flags & IP_VS_DEST_F_AVAILABLE)) { | |
184 | loh = atomic_read(&least->activeconns) * 50 | |
185 | + atomic_read(&least->inactconns); | |
186 | goto nextstage; | |
187 | } | |
188 | } | |
1da177e4 LT |
189 | return NULL; |
190 | ||
191 | /* find the destination with the weighted least load */ | |
192 | nextstage: | |
193 | for (e=e->next; e!=NULL; e=e->next) { | |
194 | dest = e->dest; | |
195 | if (dest->flags & IP_VS_DEST_F_OVERLOAD) | |
196 | continue; | |
197 | ||
198 | doh = atomic_read(&dest->activeconns) * 50 | |
199 | + atomic_read(&dest->inactconns); | |
200 | if ((loh * atomic_read(&dest->weight) > | |
201 | doh * atomic_read(&least->weight)) | |
202 | && (dest->flags & IP_VS_DEST_F_AVAILABLE)) { | |
203 | least = dest; | |
204 | loh = doh; | |
205 | } | |
206 | } | |
1da177e4 | 207 | |
1e3e238e | 208 | IP_VS_DBG_BUF(6, "%s(): server %s:%d " |
44548375 | 209 | "activeconns %d refcnt %d weight %d overhead %d\n", |
1e3e238e | 210 | __func__, |
44548375 JV |
211 | IP_VS_DBG_ADDR(least->af, &least->addr), |
212 | ntohs(least->port), | |
213 | atomic_read(&least->activeconns), | |
214 | atomic_read(&least->refcnt), | |
215 | atomic_read(&least->weight), loh); | |
1da177e4 LT |
216 | return least; |
217 | } | |
218 | ||
219 | ||
220 | /* get weighted most-connection node in the destination set */ | |
221 | static inline struct ip_vs_dest *ip_vs_dest_set_max(struct ip_vs_dest_set *set) | |
222 | { | |
223 | register struct ip_vs_dest_list *e; | |
224 | struct ip_vs_dest *dest, *most; | |
225 | int moh, doh; | |
226 | ||
227 | if (set == NULL) | |
228 | return NULL; | |
229 | ||
1da177e4 LT |
230 | /* select the first destination server, whose weight > 0 */ |
231 | for (e=set->list; e!=NULL; e=e->next) { | |
232 | most = e->dest; | |
233 | if (atomic_read(&most->weight) > 0) { | |
234 | moh = atomic_read(&most->activeconns) * 50 | |
235 | + atomic_read(&most->inactconns); | |
236 | goto nextstage; | |
237 | } | |
238 | } | |
1da177e4 LT |
239 | return NULL; |
240 | ||
241 | /* find the destination with the weighted most load */ | |
242 | nextstage: | |
243 | for (e=e->next; e!=NULL; e=e->next) { | |
244 | dest = e->dest; | |
245 | doh = atomic_read(&dest->activeconns) * 50 | |
246 | + atomic_read(&dest->inactconns); | |
247 | /* moh/mw < doh/dw ==> moh*dw < doh*mw, where mw,dw>0 */ | |
248 | if ((moh * atomic_read(&dest->weight) < | |
249 | doh * atomic_read(&most->weight)) | |
250 | && (atomic_read(&dest->weight) > 0)) { | |
251 | most = dest; | |
252 | moh = doh; | |
253 | } | |
254 | } | |
1da177e4 | 255 | |
1e3e238e | 256 | IP_VS_DBG_BUF(6, "%s(): server %s:%d " |
44548375 | 257 | "activeconns %d refcnt %d weight %d overhead %d\n", |
1e3e238e | 258 | __func__, |
44548375 JV |
259 | IP_VS_DBG_ADDR(most->af, &most->addr), ntohs(most->port), |
260 | atomic_read(&most->activeconns), | |
261 | atomic_read(&most->refcnt), | |
262 | atomic_read(&most->weight), moh); | |
1da177e4 LT |
263 | return most; |
264 | } | |
265 | ||
266 | ||
267 | /* | |
268 | * IPVS lblcr entry represents an association between destination | |
269 | * IP address and its destination server set | |
270 | */ | |
271 | struct ip_vs_lblcr_entry { | |
272 | struct list_head list; | |
44548375 JV |
273 | int af; /* address family */ |
274 | union nf_inet_addr addr; /* destination IP address */ | |
1da177e4 LT |
275 | struct ip_vs_dest_set set; /* destination server set */ |
276 | unsigned long lastuse; /* last used time */ | |
277 | }; | |
278 | ||
279 | ||
280 | /* | |
281 | * IPVS lblcr hash table | |
282 | */ | |
283 | struct ip_vs_lblcr_table { | |
1da177e4 LT |
284 | struct list_head bucket[IP_VS_LBLCR_TAB_SIZE]; /* hash bucket */ |
285 | atomic_t entries; /* number of entries */ | |
286 | int max_size; /* maximum size of entries */ | |
287 | struct timer_list periodic_timer; /* collect stale entries */ | |
288 | int rover; /* rover for expire check */ | |
289 | int counter; /* counter for no expire */ | |
290 | }; | |
291 | ||
292 | ||
293 | /* | |
294 | * IPVS LBLCR sysctl table | |
295 | */ | |
296 | ||
297 | static ctl_table vs_vars_table[] = { | |
298 | { | |
1da177e4 LT |
299 | .procname = "lblcr_expiration", |
300 | .data = &sysctl_ip_vs_lblcr_expiration, | |
301 | .maxlen = sizeof(int), | |
e905a9ed | 302 | .mode = 0644, |
6d9f239a | 303 | .proc_handler = proc_dointvec_jiffies, |
1da177e4 | 304 | }, |
f8572d8f | 305 | { } |
1da177e4 LT |
306 | }; |
307 | ||
1da177e4 LT |
308 | static struct ctl_table_header * sysctl_header; |
309 | ||
1da177e4 LT |
310 | static inline void ip_vs_lblcr_free(struct ip_vs_lblcr_entry *en) |
311 | { | |
312 | list_del(&en->list); | |
313 | ip_vs_dest_set_eraseall(&en->set); | |
314 | kfree(en); | |
315 | } | |
316 | ||
317 | ||
318 | /* | |
319 | * Returns hash value for IPVS LBLCR entry | |
320 | */ | |
44548375 JV |
321 | static inline unsigned |
322 | ip_vs_lblcr_hashkey(int af, const union nf_inet_addr *addr) | |
1da177e4 | 323 | { |
44548375 JV |
324 | __be32 addr_fold = addr->ip; |
325 | ||
326 | #ifdef CONFIG_IP_VS_IPV6 | |
327 | if (af == AF_INET6) | |
328 | addr_fold = addr->ip6[0]^addr->ip6[1]^ | |
329 | addr->ip6[2]^addr->ip6[3]; | |
330 | #endif | |
331 | return (ntohl(addr_fold)*2654435761UL) & IP_VS_LBLCR_TAB_MASK; | |
1da177e4 LT |
332 | } |
333 | ||
334 | ||
335 | /* | |
336 | * Hash an entry in the ip_vs_lblcr_table. | |
337 | * returns bool success. | |
338 | */ | |
f728bafb | 339 | static void |
1da177e4 LT |
340 | ip_vs_lblcr_hash(struct ip_vs_lblcr_table *tbl, struct ip_vs_lblcr_entry *en) |
341 | { | |
44548375 | 342 | unsigned hash = ip_vs_lblcr_hashkey(en->af, &en->addr); |
1da177e4 | 343 | |
1da177e4 LT |
344 | list_add(&en->list, &tbl->bucket[hash]); |
345 | atomic_inc(&tbl->entries); | |
1da177e4 LT |
346 | } |
347 | ||
348 | ||
1da177e4 | 349 | /* |
f728bafb SW |
350 | * Get ip_vs_lblcr_entry associated with supplied parameters. Called under |
351 | * read lock. | |
1da177e4 LT |
352 | */ |
353 | static inline struct ip_vs_lblcr_entry * | |
44548375 JV |
354 | ip_vs_lblcr_get(int af, struct ip_vs_lblcr_table *tbl, |
355 | const union nf_inet_addr *addr) | |
1da177e4 | 356 | { |
44548375 | 357 | unsigned hash = ip_vs_lblcr_hashkey(af, addr); |
1da177e4 LT |
358 | struct ip_vs_lblcr_entry *en; |
359 | ||
f728bafb | 360 | list_for_each_entry(en, &tbl->bucket[hash], list) |
44548375 | 361 | if (ip_vs_addr_equal(af, &en->addr, addr)) |
f728bafb SW |
362 | return en; |
363 | ||
364 | return NULL; | |
365 | } | |
1da177e4 | 366 | |
1da177e4 | 367 | |
f728bafb SW |
368 | /* |
369 | * Create or update an ip_vs_lblcr_entry, which is a mapping of a destination | |
370 | * IP address to a server. Called under write lock. | |
371 | */ | |
372 | static inline struct ip_vs_lblcr_entry * | |
44548375 | 373 | ip_vs_lblcr_new(struct ip_vs_lblcr_table *tbl, const union nf_inet_addr *daddr, |
f728bafb SW |
374 | struct ip_vs_dest *dest) |
375 | { | |
376 | struct ip_vs_lblcr_entry *en; | |
377 | ||
44548375 | 378 | en = ip_vs_lblcr_get(dest->af, tbl, daddr); |
f728bafb SW |
379 | if (!en) { |
380 | en = kmalloc(sizeof(*en), GFP_ATOMIC); | |
381 | if (!en) { | |
1e3e238e | 382 | pr_err("%s(): no memory\n", __func__); |
f728bafb | 383 | return NULL; |
1da177e4 | 384 | } |
f728bafb | 385 | |
44548375 JV |
386 | en->af = dest->af; |
387 | ip_vs_addr_copy(dest->af, &en->addr, daddr); | |
f728bafb SW |
388 | en->lastuse = jiffies; |
389 | ||
390 | /* initilize its dest set */ | |
391 | atomic_set(&(en->set.size), 0); | |
392 | en->set.list = NULL; | |
393 | rwlock_init(&en->set.lock); | |
394 | ||
395 | ip_vs_lblcr_hash(tbl, en); | |
1da177e4 LT |
396 | } |
397 | ||
f728bafb SW |
398 | write_lock(&en->set.lock); |
399 | ip_vs_dest_set_insert(&en->set, dest); | |
400 | write_unlock(&en->set.lock); | |
1da177e4 | 401 | |
f728bafb | 402 | return en; |
1da177e4 LT |
403 | } |
404 | ||
405 | ||
406 | /* | |
407 | * Flush all the entries of the specified table. | |
408 | */ | |
409 | static void ip_vs_lblcr_flush(struct ip_vs_lblcr_table *tbl) | |
410 | { | |
411 | int i; | |
412 | struct ip_vs_lblcr_entry *en, *nxt; | |
413 | ||
f728bafb | 414 | /* No locking required, only called during cleanup. */ |
1da177e4 | 415 | for (i=0; i<IP_VS_LBLCR_TAB_SIZE; i++) { |
1da177e4 LT |
416 | list_for_each_entry_safe(en, nxt, &tbl->bucket[i], list) { |
417 | ip_vs_lblcr_free(en); | |
1da177e4 | 418 | } |
1da177e4 LT |
419 | } |
420 | } | |
421 | ||
422 | ||
f728bafb | 423 | static inline void ip_vs_lblcr_full_check(struct ip_vs_service *svc) |
1da177e4 | 424 | { |
f728bafb | 425 | struct ip_vs_lblcr_table *tbl = svc->sched_data; |
1da177e4 LT |
426 | unsigned long now = jiffies; |
427 | int i, j; | |
428 | struct ip_vs_lblcr_entry *en, *nxt; | |
429 | ||
430 | for (i=0, j=tbl->rover; i<IP_VS_LBLCR_TAB_SIZE; i++) { | |
431 | j = (j + 1) & IP_VS_LBLCR_TAB_MASK; | |
432 | ||
f728bafb | 433 | write_lock(&svc->sched_lock); |
1da177e4 LT |
434 | list_for_each_entry_safe(en, nxt, &tbl->bucket[j], list) { |
435 | if (time_after(en->lastuse+sysctl_ip_vs_lblcr_expiration, | |
436 | now)) | |
437 | continue; | |
438 | ||
439 | ip_vs_lblcr_free(en); | |
440 | atomic_dec(&tbl->entries); | |
441 | } | |
f728bafb | 442 | write_unlock(&svc->sched_lock); |
1da177e4 LT |
443 | } |
444 | tbl->rover = j; | |
445 | } | |
446 | ||
447 | ||
448 | /* | |
449 | * Periodical timer handler for IPVS lblcr table | |
450 | * It is used to collect stale entries when the number of entries | |
451 | * exceeds the maximum size of the table. | |
452 | * | |
453 | * Fixme: we probably need more complicated algorithm to collect | |
454 | * entries that have not been used for a long time even | |
455 | * if the number of entries doesn't exceed the maximum size | |
456 | * of the table. | |
457 | * The full expiration check is for this purpose now. | |
458 | */ | |
459 | static void ip_vs_lblcr_check_expire(unsigned long data) | |
460 | { | |
f728bafb SW |
461 | struct ip_vs_service *svc = (struct ip_vs_service *) data; |
462 | struct ip_vs_lblcr_table *tbl = svc->sched_data; | |
1da177e4 LT |
463 | unsigned long now = jiffies; |
464 | int goal; | |
465 | int i, j; | |
466 | struct ip_vs_lblcr_entry *en, *nxt; | |
467 | ||
1da177e4 LT |
468 | if ((tbl->counter % COUNT_FOR_FULL_EXPIRATION) == 0) { |
469 | /* do full expiration check */ | |
f728bafb | 470 | ip_vs_lblcr_full_check(svc); |
1da177e4 LT |
471 | tbl->counter = 1; |
472 | goto out; | |
473 | } | |
474 | ||
475 | if (atomic_read(&tbl->entries) <= tbl->max_size) { | |
476 | tbl->counter++; | |
477 | goto out; | |
478 | } | |
479 | ||
480 | goal = (atomic_read(&tbl->entries) - tbl->max_size)*4/3; | |
481 | if (goal > tbl->max_size/2) | |
482 | goal = tbl->max_size/2; | |
483 | ||
484 | for (i=0, j=tbl->rover; i<IP_VS_LBLCR_TAB_SIZE; i++) { | |
485 | j = (j + 1) & IP_VS_LBLCR_TAB_MASK; | |
486 | ||
f728bafb | 487 | write_lock(&svc->sched_lock); |
1da177e4 LT |
488 | list_for_each_entry_safe(en, nxt, &tbl->bucket[j], list) { |
489 | if (time_before(now, en->lastuse+ENTRY_TIMEOUT)) | |
490 | continue; | |
491 | ||
492 | ip_vs_lblcr_free(en); | |
493 | atomic_dec(&tbl->entries); | |
494 | goal--; | |
495 | } | |
f728bafb | 496 | write_unlock(&svc->sched_lock); |
1da177e4 LT |
497 | if (goal <= 0) |
498 | break; | |
499 | } | |
500 | tbl->rover = j; | |
501 | ||
502 | out: | |
503 | mod_timer(&tbl->periodic_timer, jiffies+CHECK_EXPIRE_INTERVAL); | |
504 | } | |
505 | ||
1da177e4 LT |
506 | static int ip_vs_lblcr_init_svc(struct ip_vs_service *svc) |
507 | { | |
508 | int i; | |
509 | struct ip_vs_lblcr_table *tbl; | |
510 | ||
511 | /* | |
512 | * Allocate the ip_vs_lblcr_table for this service | |
513 | */ | |
f728bafb | 514 | tbl = kmalloc(sizeof(*tbl), GFP_ATOMIC); |
1da177e4 | 515 | if (tbl == NULL) { |
1e3e238e | 516 | pr_err("%s(): no memory\n", __func__); |
1da177e4 LT |
517 | return -ENOMEM; |
518 | } | |
519 | svc->sched_data = tbl; | |
520 | IP_VS_DBG(6, "LBLCR hash table (memory=%Zdbytes) allocated for " | |
f728bafb | 521 | "current service\n", sizeof(*tbl)); |
1da177e4 LT |
522 | |
523 | /* | |
524 | * Initialize the hash buckets | |
525 | */ | |
526 | for (i=0; i<IP_VS_LBLCR_TAB_SIZE; i++) { | |
527 | INIT_LIST_HEAD(&tbl->bucket[i]); | |
528 | } | |
1da177e4 LT |
529 | tbl->max_size = IP_VS_LBLCR_TAB_SIZE*16; |
530 | tbl->rover = 0; | |
531 | tbl->counter = 1; | |
532 | ||
533 | /* | |
534 | * Hook periodic timer for garbage collection | |
535 | */ | |
b24b8a24 | 536 | setup_timer(&tbl->periodic_timer, ip_vs_lblcr_check_expire, |
f728bafb SW |
537 | (unsigned long)svc); |
538 | mod_timer(&tbl->periodic_timer, jiffies + CHECK_EXPIRE_INTERVAL); | |
1da177e4 | 539 | |
1da177e4 LT |
540 | return 0; |
541 | } | |
542 | ||
543 | ||
544 | static int ip_vs_lblcr_done_svc(struct ip_vs_service *svc) | |
545 | { | |
546 | struct ip_vs_lblcr_table *tbl = svc->sched_data; | |
547 | ||
548 | /* remove periodic timer */ | |
549 | del_timer_sync(&tbl->periodic_timer); | |
550 | ||
551 | /* got to clean up table entries here */ | |
552 | ip_vs_lblcr_flush(tbl); | |
553 | ||
554 | /* release the table itself */ | |
f728bafb | 555 | kfree(tbl); |
1da177e4 | 556 | IP_VS_DBG(6, "LBLCR hash table (memory=%Zdbytes) released\n", |
f728bafb | 557 | sizeof(*tbl)); |
1da177e4 LT |
558 | |
559 | return 0; | |
560 | } | |
561 | ||
562 | ||
1da177e4 | 563 | static inline struct ip_vs_dest * |
44548375 | 564 | __ip_vs_lblcr_schedule(struct ip_vs_service *svc) |
1da177e4 LT |
565 | { |
566 | struct ip_vs_dest *dest, *least; | |
567 | int loh, doh; | |
568 | ||
569 | /* | |
570 | * We think the overhead of processing active connections is fifty | |
571 | * times higher than that of inactive connections in average. (This | |
572 | * fifty times might not be accurate, we will change it later.) We | |
573 | * use the following formula to estimate the overhead: | |
574 | * dest->activeconns*50 + dest->inactconns | |
575 | * and the load: | |
576 | * (dest overhead) / dest->weight | |
577 | * | |
578 | * Remember -- no floats in kernel mode!!! | |
579 | * The comparison of h1*w2 > h2*w1 is equivalent to that of | |
580 | * h1/w1 > h2/w2 | |
581 | * if every weight is larger than zero. | |
582 | * | |
583 | * The server with weight=0 is quiesced and will not receive any | |
584 | * new connection. | |
585 | */ | |
586 | list_for_each_entry(dest, &svc->destinations, n_list) { | |
587 | if (dest->flags & IP_VS_DEST_F_OVERLOAD) | |
588 | continue; | |
589 | ||
590 | if (atomic_read(&dest->weight) > 0) { | |
591 | least = dest; | |
592 | loh = atomic_read(&least->activeconns) * 50 | |
593 | + atomic_read(&least->inactconns); | |
594 | goto nextstage; | |
595 | } | |
596 | } | |
597 | return NULL; | |
598 | ||
599 | /* | |
600 | * Find the destination with the least load. | |
601 | */ | |
602 | nextstage: | |
603 | list_for_each_entry_continue(dest, &svc->destinations, n_list) { | |
604 | if (dest->flags & IP_VS_DEST_F_OVERLOAD) | |
605 | continue; | |
606 | ||
607 | doh = atomic_read(&dest->activeconns) * 50 | |
608 | + atomic_read(&dest->inactconns); | |
609 | if (loh * atomic_read(&dest->weight) > | |
610 | doh * atomic_read(&least->weight)) { | |
611 | least = dest; | |
612 | loh = doh; | |
613 | } | |
614 | } | |
615 | ||
44548375 JV |
616 | IP_VS_DBG_BUF(6, "LBLCR: server %s:%d " |
617 | "activeconns %d refcnt %d weight %d overhead %d\n", | |
618 | IP_VS_DBG_ADDR(least->af, &least->addr), | |
619 | ntohs(least->port), | |
620 | atomic_read(&least->activeconns), | |
621 | atomic_read(&least->refcnt), | |
622 | atomic_read(&least->weight), loh); | |
1da177e4 LT |
623 | |
624 | return least; | |
625 | } | |
626 | ||
627 | ||
628 | /* | |
629 | * If this destination server is overloaded and there is a less loaded | |
630 | * server, then return true. | |
631 | */ | |
632 | static inline int | |
633 | is_overloaded(struct ip_vs_dest *dest, struct ip_vs_service *svc) | |
634 | { | |
635 | if (atomic_read(&dest->activeconns) > atomic_read(&dest->weight)) { | |
636 | struct ip_vs_dest *d; | |
637 | ||
638 | list_for_each_entry(d, &svc->destinations, n_list) { | |
639 | if (atomic_read(&d->activeconns)*2 | |
640 | < atomic_read(&d->weight)) { | |
641 | return 1; | |
642 | } | |
643 | } | |
644 | } | |
645 | return 0; | |
646 | } | |
647 | ||
648 | ||
649 | /* | |
650 | * Locality-Based (weighted) Least-Connection scheduling | |
651 | */ | |
652 | static struct ip_vs_dest * | |
653 | ip_vs_lblcr_schedule(struct ip_vs_service *svc, const struct sk_buff *skb) | |
654 | { | |
f728bafb | 655 | struct ip_vs_lblcr_table *tbl = svc->sched_data; |
44548375 | 656 | struct ip_vs_iphdr iph; |
f728bafb SW |
657 | struct ip_vs_dest *dest = NULL; |
658 | struct ip_vs_lblcr_entry *en; | |
1da177e4 | 659 | |
44548375 JV |
660 | ip_vs_fill_iphdr(svc->af, skb_network_header(skb), &iph); |
661 | ||
1e3e238e | 662 | IP_VS_DBG(6, "%s(): Scheduling...\n", __func__); |
1da177e4 | 663 | |
f728bafb SW |
664 | /* First look in our cache */ |
665 | read_lock(&svc->sched_lock); | |
44548375 | 666 | en = ip_vs_lblcr_get(svc->af, tbl, &iph.daddr); |
f728bafb SW |
667 | if (en) { |
668 | /* We only hold a read lock, but this is atomic */ | |
669 | en->lastuse = jiffies; | |
670 | ||
671 | /* Get the least loaded destination */ | |
672 | read_lock(&en->set.lock); | |
1da177e4 | 673 | dest = ip_vs_dest_set_min(&en->set); |
f728bafb SW |
674 | read_unlock(&en->set.lock); |
675 | ||
676 | /* More than one destination + enough time passed by, cleanup */ | |
1da177e4 | 677 | if (atomic_read(&en->set.size) > 1 && |
f728bafb SW |
678 | time_after(jiffies, en->set.lastmod + |
679 | sysctl_ip_vs_lblcr_expiration)) { | |
1da177e4 | 680 | struct ip_vs_dest *m; |
f728bafb SW |
681 | |
682 | write_lock(&en->set.lock); | |
1da177e4 LT |
683 | m = ip_vs_dest_set_max(&en->set); |
684 | if (m) | |
685 | ip_vs_dest_set_erase(&en->set, m); | |
f728bafb SW |
686 | write_unlock(&en->set.lock); |
687 | } | |
688 | ||
689 | /* If the destination is not overloaded, use it */ | |
690 | if (dest && !is_overloaded(dest, svc)) { | |
691 | read_unlock(&svc->sched_lock); | |
692 | goto out; | |
693 | } | |
694 | ||
695 | /* The cache entry is invalid, time to schedule */ | |
44548375 | 696 | dest = __ip_vs_lblcr_schedule(svc); |
f728bafb | 697 | if (!dest) { |
68888d10 | 698 | IP_VS_ERR_RL("LBLCR: no destination available\n"); |
f728bafb SW |
699 | read_unlock(&svc->sched_lock); |
700 | return NULL; | |
1da177e4 | 701 | } |
f728bafb SW |
702 | |
703 | /* Update our cache entry */ | |
704 | write_lock(&en->set.lock); | |
705 | ip_vs_dest_set_insert(&en->set, dest); | |
706 | write_unlock(&en->set.lock); | |
707 | } | |
708 | read_unlock(&svc->sched_lock); | |
709 | ||
710 | if (dest) | |
711 | goto out; | |
712 | ||
713 | /* No cache entry, time to schedule */ | |
44548375 | 714 | dest = __ip_vs_lblcr_schedule(svc); |
f728bafb SW |
715 | if (!dest) { |
716 | IP_VS_DBG(1, "no destination available\n"); | |
717 | return NULL; | |
1da177e4 | 718 | } |
1da177e4 | 719 | |
f728bafb SW |
720 | /* If we fail to create a cache entry, we'll just use the valid dest */ |
721 | write_lock(&svc->sched_lock); | |
44548375 | 722 | ip_vs_lblcr_new(tbl, &iph.daddr, dest); |
f728bafb SW |
723 | write_unlock(&svc->sched_lock); |
724 | ||
725 | out: | |
44548375 JV |
726 | IP_VS_DBG_BUF(6, "LBLCR: destination IP address %s --> server %s:%d\n", |
727 | IP_VS_DBG_ADDR(svc->af, &iph.daddr), | |
728 | IP_VS_DBG_ADDR(svc->af, &dest->addr), ntohs(dest->port)); | |
1da177e4 LT |
729 | |
730 | return dest; | |
731 | } | |
732 | ||
733 | ||
734 | /* | |
735 | * IPVS LBLCR Scheduler structure | |
736 | */ | |
737 | static struct ip_vs_scheduler ip_vs_lblcr_scheduler = | |
738 | { | |
739 | .name = "lblcr", | |
740 | .refcnt = ATOMIC_INIT(0), | |
741 | .module = THIS_MODULE, | |
d149ccc9 | 742 | .n_list = LIST_HEAD_INIT(ip_vs_lblcr_scheduler.n_list), |
1da177e4 LT |
743 | .init_service = ip_vs_lblcr_init_svc, |
744 | .done_service = ip_vs_lblcr_done_svc, | |
1da177e4 LT |
745 | .schedule = ip_vs_lblcr_schedule, |
746 | }; | |
747 | ||
748 | ||
749 | static int __init ip_vs_lblcr_init(void) | |
750 | { | |
a014bc8f PE |
751 | int ret; |
752 | ||
90754f8e | 753 | sysctl_header = register_sysctl_paths(net_vs_ctl_path, vs_vars_table); |
a014bc8f PE |
754 | ret = register_ip_vs_scheduler(&ip_vs_lblcr_scheduler); |
755 | if (ret) | |
756 | unregister_sysctl_table(sysctl_header); | |
757 | return ret; | |
1da177e4 LT |
758 | } |
759 | ||
760 | ||
761 | static void __exit ip_vs_lblcr_cleanup(void) | |
762 | { | |
1da177e4 LT |
763 | unregister_sysctl_table(sysctl_header); |
764 | unregister_ip_vs_scheduler(&ip_vs_lblcr_scheduler); | |
765 | } | |
766 | ||
767 | ||
768 | module_init(ip_vs_lblcr_init); | |
769 | module_exit(ip_vs_lblcr_cleanup); | |
770 | MODULE_LICENSE("GPL"); |