1 /*
2 * GPL HEADER START
3 *
4 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 2 only,
8 * as published by the Free Software Foundation.
9 *
10 * This program is distributed in the hope that it will be useful, but
11 * WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 * General Public License version 2 for more details (a copy is included
14 * in the LICENSE file that accompanied this code).
15 *
16 * You should have received a copy of the GNU General Public License
17 * version 2 along with this program; If not, see
18 * http://www.sun.com/software/products/lustre/docs/GPLv2.pdf
19 *
20 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
21 * CA 95054 USA or visit www.sun.com if you need additional information or
22 * have any questions.
23 *
24 * GPL HEADER END
25 */
26 /*
27 * Copyright (c) 2003, 2010, Oracle and/or its affiliates. All rights reserved.
28 * Use is subject to license terms.
29 *
30 * Copyright (c) 2011, 2012, Intel Corporation.
31 */
32 /*
33 * This file is part of Lustre, http://www.lustre.org/
34 * Lustre is a trademark of Sun Microsystems, Inc.
35 *
36 * lustre/ptlrpc/ptlrpcd.c
37 */
38
39 /** \defgroup ptlrpcd PortalRPC daemon
40 *
41 * ptlrpcd is a special thread with its own set where other user might add
42 * requests when they don't want to wait for their completion.
43 * PtlRPCD will take care of sending such requests and then processing their
44 * replies and calling completion callbacks as necessary.
45 * The callbacks are called directly from ptlrpcd context.
46 * It is important to never significantly block (esp. on RPCs!) within such
47 * completion handler or a deadlock might occur where ptlrpcd enters some
48 * callback that attempts to send another RPC and wait for it to return,
49 * during which time ptlrpcd is completely blocked, so e.g. if import
50 * fails, recovery cannot progress because connection requests are also
51 * sent by ptlrpcd.
52 *
53 * @{
54 */
55
56 #define DEBUG_SUBSYSTEM S_RPC
57
58 #include "../../include/linux/libcfs/libcfs.h"
59
60 #include "../include/lustre_net.h"
61 #include "../include/lustre_lib.h"
62 #include "../include/lustre_ha.h"
63 #include "../include/obd_class.h" /* for obd_zombie */
64 #include "../include/obd_support.h" /* for OBD_FAIL_CHECK */
65 #include "../include/cl_object.h" /* cl_env_{get,put}() */
66 #include "../include/lprocfs_status.h"
67
68 #include "ptlrpc_internal.h"
69
70 struct ptlrpcd {
71 int pd_size;
72 int pd_index;
73 int pd_nthreads;
74 struct ptlrpcd_ctl pd_thread_rcv;
75 struct ptlrpcd_ctl pd_threads[0];
76 };
77
78 static int max_ptlrpcds;
79 module_param(max_ptlrpcds, int, 0644);
80 MODULE_PARM_DESC(max_ptlrpcds, "Max ptlrpcd thread count to be started.");
81
82 static int ptlrpcd_bind_policy = PDB_POLICY_PAIR;
83 module_param(ptlrpcd_bind_policy, int, 0644);
84 MODULE_PARM_DESC(ptlrpcd_bind_policy, "Ptlrpcd threads binding mode.");
85 static struct ptlrpcd *ptlrpcds;
86
87 struct mutex ptlrpcd_mutex;
88 static int ptlrpcd_users;
89
ptlrpcd_wake(struct ptlrpc_request * req)90 void ptlrpcd_wake(struct ptlrpc_request *req)
91 {
92 struct ptlrpc_request_set *rq_set = req->rq_set;
93
94 LASSERT(rq_set != NULL);
95
96 wake_up(&rq_set->set_waitq);
97 }
98 EXPORT_SYMBOL(ptlrpcd_wake);
99
100 static struct ptlrpcd_ctl *
ptlrpcd_select_pc(struct ptlrpc_request * req,pdl_policy_t policy,int index)101 ptlrpcd_select_pc(struct ptlrpc_request *req, pdl_policy_t policy, int index)
102 {
103 int idx = 0;
104
105 if (req != NULL && req->rq_send_state != LUSTRE_IMP_FULL)
106 return &ptlrpcds->pd_thread_rcv;
107
108 switch (policy) {
109 case PDL_POLICY_SAME:
110 idx = smp_processor_id() % ptlrpcds->pd_nthreads;
111 break;
112 case PDL_POLICY_LOCAL:
113 /* Before CPU partition patches available, process it the same
114 * as "PDL_POLICY_ROUND". */
115 # ifdef CFS_CPU_MODE_NUMA
116 # warning "fix this code to use new CPU partition APIs"
117 # endif
118 /* Fall through to PDL_POLICY_ROUND until the CPU
119 * CPU partition patches are available. */
120 index = -1;
121 case PDL_POLICY_PREFERRED:
122 if (index >= 0 && index < num_online_cpus()) {
123 idx = index % ptlrpcds->pd_nthreads;
124 break;
125 }
126 /* Fall through to PDL_POLICY_ROUND for bad index. */
127 default:
128 /* Fall through to PDL_POLICY_ROUND for unknown policy. */
129 case PDL_POLICY_ROUND:
130 /* We do not care whether it is strict load balance. */
131 idx = ptlrpcds->pd_index + 1;
132 if (idx == smp_processor_id())
133 idx++;
134 idx %= ptlrpcds->pd_nthreads;
135 ptlrpcds->pd_index = idx;
136 break;
137 }
138
139 return &ptlrpcds->pd_threads[idx];
140 }
141
142 /**
143 * Move all request from an existing request set to the ptlrpcd queue.
144 * All requests from the set must be in phase RQ_PHASE_NEW.
145 */
ptlrpcd_add_rqset(struct ptlrpc_request_set * set)146 void ptlrpcd_add_rqset(struct ptlrpc_request_set *set)
147 {
148 struct list_head *tmp, *pos;
149 struct ptlrpcd_ctl *pc;
150 struct ptlrpc_request_set *new;
151 int count, i;
152
153 pc = ptlrpcd_select_pc(NULL, PDL_POLICY_LOCAL, -1);
154 new = pc->pc_set;
155
156 list_for_each_safe(pos, tmp, &set->set_requests) {
157 struct ptlrpc_request *req =
158 list_entry(pos, struct ptlrpc_request,
159 rq_set_chain);
160
161 LASSERT(req->rq_phase == RQ_PHASE_NEW);
162 req->rq_set = new;
163 req->rq_queued_time = cfs_time_current();
164 }
165
166 spin_lock(&new->set_new_req_lock);
167 list_splice_init(&set->set_requests, &new->set_new_requests);
168 i = atomic_read(&set->set_remaining);
169 count = atomic_add_return(i, &new->set_new_count);
170 atomic_set(&set->set_remaining, 0);
171 spin_unlock(&new->set_new_req_lock);
172 if (count == i) {
173 wake_up(&new->set_waitq);
174
175 /* XXX: It maybe unnecessary to wakeup all the partners. But to
176 * guarantee the async RPC can be processed ASAP, we have
177 * no other better choice. It maybe fixed in future. */
178 for (i = 0; i < pc->pc_npartners; i++)
179 wake_up(&pc->pc_partners[i]->pc_set->set_waitq);
180 }
181 }
182 EXPORT_SYMBOL(ptlrpcd_add_rqset);
183
184 /**
185 * Return transferred RPCs count.
186 */
ptlrpcd_steal_rqset(struct ptlrpc_request_set * des,struct ptlrpc_request_set * src)187 static int ptlrpcd_steal_rqset(struct ptlrpc_request_set *des,
188 struct ptlrpc_request_set *src)
189 {
190 struct list_head *tmp, *pos;
191 struct ptlrpc_request *req;
192 int rc = 0;
193
194 spin_lock(&src->set_new_req_lock);
195 if (likely(!list_empty(&src->set_new_requests))) {
196 list_for_each_safe(pos, tmp, &src->set_new_requests) {
197 req = list_entry(pos, struct ptlrpc_request,
198 rq_set_chain);
199 req->rq_set = des;
200 }
201 list_splice_init(&src->set_new_requests,
202 &des->set_requests);
203 rc = atomic_read(&src->set_new_count);
204 atomic_add(rc, &des->set_remaining);
205 atomic_set(&src->set_new_count, 0);
206 }
207 spin_unlock(&src->set_new_req_lock);
208 return rc;
209 }
210
211 /**
212 * Requests that are added to the ptlrpcd queue are sent via
213 * ptlrpcd_check->ptlrpc_check_set().
214 */
ptlrpcd_add_req(struct ptlrpc_request * req,pdl_policy_t policy,int idx)215 void ptlrpcd_add_req(struct ptlrpc_request *req, pdl_policy_t policy, int idx)
216 {
217 struct ptlrpcd_ctl *pc;
218
219 if (req->rq_reqmsg)
220 lustre_msg_set_jobid(req->rq_reqmsg, NULL);
221
222 spin_lock(&req->rq_lock);
223 if (req->rq_invalid_rqset) {
224 struct l_wait_info lwi = LWI_TIMEOUT(cfs_time_seconds(5),
225 back_to_sleep, NULL);
226
227 req->rq_invalid_rqset = 0;
228 spin_unlock(&req->rq_lock);
229 l_wait_event(req->rq_set_waitq, (req->rq_set == NULL), &lwi);
230 } else if (req->rq_set) {
231 /* If we have a valid "rq_set", just reuse it to avoid double
232 * linked. */
233 LASSERT(req->rq_phase == RQ_PHASE_NEW);
234 LASSERT(req->rq_send_state == LUSTRE_IMP_REPLAY);
235
236 /* ptlrpc_check_set will decrease the count */
237 atomic_inc(&req->rq_set->set_remaining);
238 spin_unlock(&req->rq_lock);
239 wake_up(&req->rq_set->set_waitq);
240 return;
241 } else {
242 spin_unlock(&req->rq_lock);
243 }
244
245 pc = ptlrpcd_select_pc(req, policy, idx);
246
247 DEBUG_REQ(D_INFO, req, "add req [%p] to pc [%s:%d]",
248 req, pc->pc_name, pc->pc_index);
249
250 ptlrpc_set_add_new_req(pc, req);
251 }
252 EXPORT_SYMBOL(ptlrpcd_add_req);
253
ptlrpc_reqset_get(struct ptlrpc_request_set * set)254 static inline void ptlrpc_reqset_get(struct ptlrpc_request_set *set)
255 {
256 atomic_inc(&set->set_refcount);
257 }
258
259 /**
260 * Check if there is more work to do on ptlrpcd set.
261 * Returns 1 if yes.
262 */
ptlrpcd_check(struct lu_env * env,struct ptlrpcd_ctl * pc)263 static int ptlrpcd_check(struct lu_env *env, struct ptlrpcd_ctl *pc)
264 {
265 struct list_head *tmp, *pos;
266 struct ptlrpc_request *req;
267 struct ptlrpc_request_set *set = pc->pc_set;
268 int rc = 0;
269 int rc2;
270
271 if (atomic_read(&set->set_new_count)) {
272 spin_lock(&set->set_new_req_lock);
273 if (likely(!list_empty(&set->set_new_requests))) {
274 list_splice_init(&set->set_new_requests,
275 &set->set_requests);
276 atomic_add(atomic_read(&set->set_new_count),
277 &set->set_remaining);
278 atomic_set(&set->set_new_count, 0);
279 /*
280 * Need to calculate its timeout.
281 */
282 rc = 1;
283 }
284 spin_unlock(&set->set_new_req_lock);
285 }
286
287 /* We should call lu_env_refill() before handling new requests to make
288 * sure that env key the requests depending on really exists.
289 */
290 rc2 = lu_env_refill(env);
291 if (rc2 != 0) {
292 /*
293 * XXX This is very awkward situation, because
294 * execution can neither continue (request
295 * interpreters assume that env is set up), nor repeat
296 * the loop (as this potentially results in a tight
297 * loop of -ENOMEM's).
298 *
299 * Fortunately, refill only ever does something when
300 * new modules are loaded, i.e., early during boot up.
301 */
302 CERROR("Failure to refill session: %d\n", rc2);
303 return rc;
304 }
305
306 if (atomic_read(&set->set_remaining))
307 rc |= ptlrpc_check_set(env, set);
308
309 /* NB: ptlrpc_check_set has already moved completed request at the
310 * head of seq::set_requests */
311 list_for_each_safe(pos, tmp, &set->set_requests) {
312 req = list_entry(pos, struct ptlrpc_request, rq_set_chain);
313 if (req->rq_phase != RQ_PHASE_COMPLETE)
314 break;
315
316 list_del_init(&req->rq_set_chain);
317 req->rq_set = NULL;
318 ptlrpc_req_finished(req);
319 }
320
321 if (rc == 0) {
322 /*
323 * If new requests have been added, make sure to wake up.
324 */
325 rc = atomic_read(&set->set_new_count);
326
327 /* If we have nothing to do, check whether we can take some
328 * work from our partner threads. */
329 if (rc == 0 && pc->pc_npartners > 0) {
330 struct ptlrpcd_ctl *partner;
331 struct ptlrpc_request_set *ps;
332 int first = pc->pc_cursor;
333
334 do {
335 partner = pc->pc_partners[pc->pc_cursor++];
336 if (pc->pc_cursor >= pc->pc_npartners)
337 pc->pc_cursor = 0;
338 if (partner == NULL)
339 continue;
340
341 spin_lock(&partner->pc_lock);
342 ps = partner->pc_set;
343 if (ps == NULL) {
344 spin_unlock(&partner->pc_lock);
345 continue;
346 }
347
348 ptlrpc_reqset_get(ps);
349 spin_unlock(&partner->pc_lock);
350
351 if (atomic_read(&ps->set_new_count)) {
352 rc = ptlrpcd_steal_rqset(set, ps);
353 if (rc > 0)
354 CDEBUG(D_RPCTRACE, "transfer %d async RPCs [%d->%d]\n",
355 rc, partner->pc_index,
356 pc->pc_index);
357 }
358 ptlrpc_reqset_put(ps);
359 } while (rc == 0 && pc->pc_cursor != first);
360 }
361 }
362
363 return rc;
364 }
365
366 /**
367 * Main ptlrpcd thread.
368 * ptlrpc's code paths like to execute in process context, so we have this
369 * thread which spins on a set which contains the rpcs and sends them.
370 *
371 */
ptlrpcd(void * arg)372 static int ptlrpcd(void *arg)
373 {
374 struct ptlrpcd_ctl *pc = arg;
375 struct ptlrpc_request_set *set = pc->pc_set;
376 struct lu_env env = { .le_ses = NULL };
377 int rc, exit = 0;
378
379 unshare_fs_struct();
380 #if defined(CONFIG_SMP)
381 if (test_bit(LIOD_BIND, &pc->pc_flags)) {
382 int index = pc->pc_index;
383
384 if (index >= 0 && index < num_possible_cpus()) {
385 while (!cpu_online(index)) {
386 if (++index >= num_possible_cpus())
387 index = 0;
388 }
389 set_cpus_allowed_ptr(current,
390 cpumask_of_node(cpu_to_node(index)));
391 }
392 }
393 #endif
394 /*
395 * XXX So far only "client" ptlrpcd uses an environment. In
396 * the future, ptlrpcd thread (or a thread-set) has to given
397 * an argument, describing its "scope".
398 */
399 rc = lu_context_init(&env.le_ctx,
400 LCT_CL_THREAD|LCT_REMEMBER|LCT_NOREF);
401 complete(&pc->pc_starting);
402
403 if (rc != 0)
404 return rc;
405
406 /*
407 * This mainloop strongly resembles ptlrpc_set_wait() except that our
408 * set never completes. ptlrpcd_check() calls ptlrpc_check_set() when
409 * there are requests in the set. New requests come in on the set's
410 * new_req_list and ptlrpcd_check() moves them into the set.
411 */
412 do {
413 struct l_wait_info lwi;
414 int timeout;
415
416 timeout = ptlrpc_set_next_timeout(set);
417 lwi = LWI_TIMEOUT(cfs_time_seconds(timeout ? timeout : 1),
418 ptlrpc_expired_set, set);
419
420 lu_context_enter(&env.le_ctx);
421 l_wait_event(set->set_waitq,
422 ptlrpcd_check(&env, pc), &lwi);
423 lu_context_exit(&env.le_ctx);
424
425 /*
426 * Abort inflight rpcs for forced stop case.
427 */
428 if (test_bit(LIOD_STOP, &pc->pc_flags)) {
429 if (test_bit(LIOD_FORCE, &pc->pc_flags))
430 ptlrpc_abort_set(set);
431 exit++;
432 }
433
434 /*
435 * Let's make one more loop to make sure that ptlrpcd_check()
436 * copied all raced new rpcs into the set so we can kill them.
437 */
438 } while (exit < 2);
439
440 /*
441 * Wait for inflight requests to drain.
442 */
443 if (!list_empty(&set->set_requests))
444 ptlrpc_set_wait(set);
445 lu_context_fini(&env.le_ctx);
446
447 complete(&pc->pc_finishing);
448
449 return 0;
450 }
451
452 /* XXX: We want multiple CPU cores to share the async RPC load. So we start many
453 * ptlrpcd threads. We also want to reduce the ptlrpcd overhead caused by
454 * data transfer cross-CPU cores. So we bind ptlrpcd thread to specified
455 * CPU core. But binding all ptlrpcd threads maybe cause response delay
456 * because of some CPU core(s) busy with other loads.
457 *
458 * For example: "ls -l", some async RPCs for statahead are assigned to
459 * ptlrpcd_0, and ptlrpcd_0 is bound to CPU_0, but CPU_0 may be quite busy
460 * with other non-ptlrpcd, like "ls -l" itself (we want to the "ls -l"
461 * thread, statahead thread, and ptlrpcd thread can run in parallel), under
462 * such case, the statahead async RPCs can not be processed in time, it is
463 * unexpected. If ptlrpcd_0 can be re-scheduled on other CPU core, it may
464 * be better. But it breaks former data transfer policy.
465 *
466 * So we shouldn't be blind for avoiding the data transfer. We make some
467 * compromise: divide the ptlrpcd threads pool into two parts. One part is
468 * for bound mode, each ptlrpcd thread in this part is bound to some CPU
469 * core. The other part is for free mode, all the ptlrpcd threads in the
470 * part can be scheduled on any CPU core. We specify some partnership
471 * between bound mode ptlrpcd thread(s) and free mode ptlrpcd thread(s),
472 * and the async RPC load within the partners are shared.
473 *
474 * It can partly avoid data transfer cross-CPU (if the bound mode ptlrpcd
475 * thread can be scheduled in time), and try to guarantee the async RPC
476 * processed ASAP (as long as the free mode ptlrpcd thread can be scheduled
477 * on any CPU core).
478 *
479 * As for how to specify the partnership between bound mode ptlrpcd
480 * thread(s) and free mode ptlrpcd thread(s), the simplest way is to use
481 * <free bound> pair. In future, we can specify some more complex
482 * partnership based on the patches for CPU partition. But before such
483 * patches are available, we prefer to use the simplest one.
484 */
485 # ifdef CFS_CPU_MODE_NUMA
486 # warning "fix ptlrpcd_bind() to use new CPU partition APIs"
487 # endif
ptlrpcd_bind(int index,int max)488 static int ptlrpcd_bind(int index, int max)
489 {
490 struct ptlrpcd_ctl *pc;
491 int rc = 0;
492 #if defined(CONFIG_NUMA)
493 cpumask_t mask;
494 #endif
495
496 LASSERT(index <= max - 1);
497 pc = &ptlrpcds->pd_threads[index];
498 switch (ptlrpcd_bind_policy) {
499 case PDB_POLICY_NONE:
500 pc->pc_npartners = -1;
501 break;
502 case PDB_POLICY_FULL:
503 pc->pc_npartners = 0;
504 set_bit(LIOD_BIND, &pc->pc_flags);
505 break;
506 case PDB_POLICY_PAIR:
507 LASSERT(max % 2 == 0);
508 pc->pc_npartners = 1;
509 break;
510 case PDB_POLICY_NEIGHBOR:
511 #if defined(CONFIG_NUMA)
512 {
513 int i;
514 cpumask_copy(&mask, cpumask_of_node(cpu_to_node(index)));
515 for (i = max; i < num_online_cpus(); i++)
516 cpumask_clear_cpu(i, &mask);
517 pc->pc_npartners = cpumask_weight(&mask) - 1;
518 set_bit(LIOD_BIND, &pc->pc_flags);
519 }
520 #else
521 LASSERT(max >= 3);
522 pc->pc_npartners = 2;
523 #endif
524 break;
525 default:
526 CERROR("unknown ptlrpcd bind policy %d\n", ptlrpcd_bind_policy);
527 rc = -EINVAL;
528 }
529
530 if (rc == 0 && pc->pc_npartners > 0) {
531 OBD_ALLOC(pc->pc_partners,
532 sizeof(struct ptlrpcd_ctl *) * pc->pc_npartners);
533 if (pc->pc_partners == NULL) {
534 pc->pc_npartners = 0;
535 rc = -ENOMEM;
536 } else {
537 switch (ptlrpcd_bind_policy) {
538 case PDB_POLICY_PAIR:
539 if (index & 0x1) {
540 set_bit(LIOD_BIND, &pc->pc_flags);
541 pc->pc_partners[0] = &ptlrpcds->
542 pd_threads[index - 1];
543 ptlrpcds->pd_threads[index - 1].
544 pc_partners[0] = pc;
545 }
546 break;
547 case PDB_POLICY_NEIGHBOR:
548 #if defined(CONFIG_NUMA)
549 {
550 struct ptlrpcd_ctl *ppc;
551 int i, pidx;
552 /* partners are cores in the same NUMA node.
553 * setup partnership only with ptlrpcd threads
554 * that are already initialized
555 */
556 for (pidx = 0, i = 0; i < index; i++) {
557 if (cpumask_test_cpu(i, &mask)) {
558 ppc = &ptlrpcds->pd_threads[i];
559 pc->pc_partners[pidx++] = ppc;
560 ppc->pc_partners[ppc->
561 pc_npartners++] = pc;
562 }
563 }
564 /* adjust number of partners to the number
565 * of partnership really setup */
566 pc->pc_npartners = pidx;
567 }
568 #else
569 if (index & 0x1)
570 set_bit(LIOD_BIND, &pc->pc_flags);
571 if (index > 0) {
572 pc->pc_partners[0] = &ptlrpcds->
573 pd_threads[index - 1];
574 ptlrpcds->pd_threads[index - 1].
575 pc_partners[1] = pc;
576 if (index == max - 1) {
577 pc->pc_partners[1] =
578 &ptlrpcds->pd_threads[0];
579 ptlrpcds->pd_threads[0].
580 pc_partners[0] = pc;
581 }
582 }
583 #endif
584 break;
585 }
586 }
587 }
588
589 return rc;
590 }
591
592
ptlrpcd_start(int index,int max,const char * name,struct ptlrpcd_ctl * pc)593 int ptlrpcd_start(int index, int max, const char *name, struct ptlrpcd_ctl *pc)
594 {
595 int rc;
596
597 /*
598 * Do not allow start second thread for one pc.
599 */
600 if (test_and_set_bit(LIOD_START, &pc->pc_flags)) {
601 CWARN("Starting second thread (%s) for same pc %p\n",
602 name, pc);
603 return 0;
604 }
605
606 pc->pc_index = index;
607 init_completion(&pc->pc_starting);
608 init_completion(&pc->pc_finishing);
609 spin_lock_init(&pc->pc_lock);
610 strlcpy(pc->pc_name, name, sizeof(pc->pc_name));
611 pc->pc_set = ptlrpc_prep_set();
612 if (pc->pc_set == NULL) {
613 rc = -ENOMEM;
614 goto out;
615 }
616
617 /*
618 * So far only "client" ptlrpcd uses an environment. In the future,
619 * ptlrpcd thread (or a thread-set) has to be given an argument,
620 * describing its "scope".
621 */
622 rc = lu_context_init(&pc->pc_env.le_ctx, LCT_CL_THREAD|LCT_REMEMBER);
623 if (rc != 0)
624 goto out_set;
625
626 {
627 struct task_struct *task;
628 if (index >= 0) {
629 rc = ptlrpcd_bind(index, max);
630 if (rc < 0)
631 goto out_env;
632 }
633
634 task = kthread_run(ptlrpcd, pc, "%s", pc->pc_name);
635 if (IS_ERR(task)) {
636 rc = PTR_ERR(task);
637 goto out_env;
638 }
639
640 wait_for_completion(&pc->pc_starting);
641 }
642 return 0;
643
644 out_env:
645 lu_context_fini(&pc->pc_env.le_ctx);
646
647 out_set:
648 if (pc->pc_set != NULL) {
649 struct ptlrpc_request_set *set = pc->pc_set;
650
651 spin_lock(&pc->pc_lock);
652 pc->pc_set = NULL;
653 spin_unlock(&pc->pc_lock);
654 ptlrpc_set_destroy(set);
655 }
656 clear_bit(LIOD_BIND, &pc->pc_flags);
657
658 out:
659 clear_bit(LIOD_START, &pc->pc_flags);
660 return rc;
661 }
662
ptlrpcd_stop(struct ptlrpcd_ctl * pc,int force)663 void ptlrpcd_stop(struct ptlrpcd_ctl *pc, int force)
664 {
665 if (!test_bit(LIOD_START, &pc->pc_flags)) {
666 CWARN("Thread for pc %p was not started\n", pc);
667 return;
668 }
669
670 set_bit(LIOD_STOP, &pc->pc_flags);
671 if (force)
672 set_bit(LIOD_FORCE, &pc->pc_flags);
673 wake_up(&pc->pc_set->set_waitq);
674 }
675
ptlrpcd_free(struct ptlrpcd_ctl * pc)676 void ptlrpcd_free(struct ptlrpcd_ctl *pc)
677 {
678 struct ptlrpc_request_set *set = pc->pc_set;
679
680 if (!test_bit(LIOD_START, &pc->pc_flags)) {
681 CWARN("Thread for pc %p was not started\n", pc);
682 goto out;
683 }
684
685 wait_for_completion(&pc->pc_finishing);
686 lu_context_fini(&pc->pc_env.le_ctx);
687
688 spin_lock(&pc->pc_lock);
689 pc->pc_set = NULL;
690 spin_unlock(&pc->pc_lock);
691 ptlrpc_set_destroy(set);
692
693 clear_bit(LIOD_START, &pc->pc_flags);
694 clear_bit(LIOD_STOP, &pc->pc_flags);
695 clear_bit(LIOD_FORCE, &pc->pc_flags);
696 clear_bit(LIOD_BIND, &pc->pc_flags);
697
698 out:
699 if (pc->pc_npartners > 0) {
700 LASSERT(pc->pc_partners != NULL);
701
702 OBD_FREE(pc->pc_partners,
703 sizeof(struct ptlrpcd_ctl *) * pc->pc_npartners);
704 pc->pc_partners = NULL;
705 }
706 pc->pc_npartners = 0;
707 }
708
ptlrpcd_fini(void)709 static void ptlrpcd_fini(void)
710 {
711 int i;
712
713 if (ptlrpcds != NULL) {
714 for (i = 0; i < ptlrpcds->pd_nthreads; i++)
715 ptlrpcd_stop(&ptlrpcds->pd_threads[i], 0);
716 for (i = 0; i < ptlrpcds->pd_nthreads; i++)
717 ptlrpcd_free(&ptlrpcds->pd_threads[i]);
718 ptlrpcd_stop(&ptlrpcds->pd_thread_rcv, 0);
719 ptlrpcd_free(&ptlrpcds->pd_thread_rcv);
720 OBD_FREE(ptlrpcds, ptlrpcds->pd_size);
721 ptlrpcds = NULL;
722 }
723 }
724
ptlrpcd_init(void)725 static int ptlrpcd_init(void)
726 {
727 int nthreads = num_online_cpus();
728 char name[16];
729 int size, i = -1, j, rc = 0;
730
731 if (max_ptlrpcds > 0 && max_ptlrpcds < nthreads)
732 nthreads = max_ptlrpcds;
733 if (nthreads < 2)
734 nthreads = 2;
735 if (nthreads < 3 && ptlrpcd_bind_policy == PDB_POLICY_NEIGHBOR)
736 ptlrpcd_bind_policy = PDB_POLICY_PAIR;
737 else if (nthreads % 2 != 0 && ptlrpcd_bind_policy == PDB_POLICY_PAIR)
738 nthreads &= ~1; /* make sure it is even */
739
740 size = offsetof(struct ptlrpcd, pd_threads[nthreads]);
741 OBD_ALLOC(ptlrpcds, size);
742 if (ptlrpcds == NULL) {
743 rc = -ENOMEM;
744 goto out;
745 }
746
747 snprintf(name, sizeof(name), "ptlrpcd_rcv");
748 set_bit(LIOD_RECOVERY, &ptlrpcds->pd_thread_rcv.pc_flags);
749 rc = ptlrpcd_start(-1, nthreads, name, &ptlrpcds->pd_thread_rcv);
750 if (rc < 0)
751 goto out;
752
753 /* XXX: We start nthreads ptlrpc daemons. Each of them can process any
754 * non-recovery async RPC to improve overall async RPC efficiency.
755 *
756 * But there are some issues with async I/O RPCs and async non-I/O
757 * RPCs processed in the same set under some cases. The ptlrpcd may
758 * be blocked by some async I/O RPC(s), then will cause other async
759 * non-I/O RPC(s) can not be processed in time.
760 *
761 * Maybe we should distinguish blocked async RPCs from non-blocked
762 * async RPCs, and process them in different ptlrpcd sets to avoid
763 * unnecessary dependency. But how to distribute async RPCs load
764 * among all the ptlrpc daemons becomes another trouble. */
765 for (i = 0; i < nthreads; i++) {
766 snprintf(name, sizeof(name), "ptlrpcd_%d", i);
767 rc = ptlrpcd_start(i, nthreads, name, &ptlrpcds->pd_threads[i]);
768 if (rc < 0)
769 goto out;
770 }
771
772 ptlrpcds->pd_size = size;
773 ptlrpcds->pd_index = 0;
774 ptlrpcds->pd_nthreads = nthreads;
775
776 out:
777 if (rc != 0 && ptlrpcds != NULL) {
778 for (j = 0; j <= i; j++)
779 ptlrpcd_stop(&ptlrpcds->pd_threads[j], 0);
780 for (j = 0; j <= i; j++)
781 ptlrpcd_free(&ptlrpcds->pd_threads[j]);
782 ptlrpcd_stop(&ptlrpcds->pd_thread_rcv, 0);
783 ptlrpcd_free(&ptlrpcds->pd_thread_rcv);
784 OBD_FREE(ptlrpcds, size);
785 ptlrpcds = NULL;
786 }
787
788 return 0;
789 }
790
ptlrpcd_addref(void)791 int ptlrpcd_addref(void)
792 {
793 int rc = 0;
794
795 mutex_lock(&ptlrpcd_mutex);
796 if (++ptlrpcd_users == 1)
797 rc = ptlrpcd_init();
798 mutex_unlock(&ptlrpcd_mutex);
799 return rc;
800 }
801 EXPORT_SYMBOL(ptlrpcd_addref);
802
ptlrpcd_decref(void)803 void ptlrpcd_decref(void)
804 {
805 mutex_lock(&ptlrpcd_mutex);
806 if (--ptlrpcd_users == 0)
807 ptlrpcd_fini();
808 mutex_unlock(&ptlrpcd_mutex);
809 }
810 EXPORT_SYMBOL(ptlrpcd_decref);
811 /** @} ptlrpcd */
812