4 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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,
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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).
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
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
27 * Copyright (c) 2003, 2010, Oracle and/or its affiliates. All rights reserved.
28 * Use is subject to license terms.
30 * Copyright (c) 2011, 2012, Whamcloud, Inc.
33 * This file is part of Lustre, http://www.lustre.org/
34 * Lustre is a trademark of Sun Microsystems, Inc.
36 * lustre/ptlrpc/ptlrpcd.c
39 /** \defgroup ptlrpcd PortalRPC daemon
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
56 #define DEBUG_SUBSYSTEM S_RPC
59 # include <libcfs/libcfs.h>
60 #else /* __KERNEL__ */
61 # include <liblustre.h>
65 #include <lustre_net.h>
66 # include <lustre_lib.h>
68 #include <lustre_ha.h>
69 #include <obd_class.h> /* for obd_zombie */
70 #include <obd_support.h> /* for OBD_FAIL_CHECK */
71 #include <cl_object.h> /* cl_env_{get,put}() */
72 #include <lprocfs_status.h>
74 #include "ptlrpc_internal.h"
80 struct ptlrpcd_ctl pd_thread_rcv;
81 struct ptlrpcd_ctl pd_threads[0];
85 static int max_ptlrpcds;
86 CFS_MODULE_PARM(max_ptlrpcds, "i", int, 0644,
87 "Max ptlrpcd thread count to be started.");
89 static int ptlrpcd_bind_policy = PDB_POLICY_PAIR;
90 CFS_MODULE_PARM(ptlrpcd_bind_policy, "i", int, 0644,
91 "Ptlrpcd threads binding mode.");
93 static struct ptlrpcd *ptlrpcds;
95 struct mutex ptlrpcd_mutex;
96 static int ptlrpcd_users = 0;
98 void ptlrpcd_wake(struct ptlrpc_request *req)
100 struct ptlrpc_request_set *rq_set = req->rq_set;
102 LASSERT(rq_set != NULL);
104 cfs_waitq_signal(&rq_set->set_waitq);
106 EXPORT_SYMBOL(ptlrpcd_wake);
108 static struct ptlrpcd_ctl *
109 ptlrpcd_select_pc(struct ptlrpc_request *req, pdl_policy_t policy, int index)
113 if (req != NULL && req->rq_send_state != LUSTRE_IMP_FULL)
114 return &ptlrpcds->pd_thread_rcv;
118 case PDL_POLICY_SAME:
119 idx = cfs_smp_processor_id() % ptlrpcds->pd_nthreads;
121 case PDL_POLICY_LOCAL:
122 /* Before CPU partition patches available, process it the same
123 * as "PDL_POLICY_ROUND". */
124 # ifdef CFS_CPU_MODE_NUMA
125 # warning "fix this code to use new CPU partition APIs"
127 /* Fall through to PDL_POLICY_ROUND until the CPU
128 * CPU partition patches are available. */
130 case PDL_POLICY_PREFERRED:
131 if (index >= 0 && index < cfs_num_online_cpus()) {
132 idx = index % ptlrpcds->pd_nthreads;
135 /* Fall through to PDL_POLICY_ROUND for bad index. */
137 /* Fall through to PDL_POLICY_ROUND for unknown policy. */
138 case PDL_POLICY_ROUND:
139 /* We do not care whether it is strict load balance. */
140 idx = ptlrpcds->pd_index + 1;
141 if (idx == cfs_smp_processor_id())
143 idx %= ptlrpcds->pd_nthreads;
144 ptlrpcds->pd_index = idx;
147 #endif /* __KERNEL__ */
149 return &ptlrpcds->pd_threads[idx];
153 * Move all request from an existing request set to the ptlrpcd queue.
154 * All requests from the set must be in phase RQ_PHASE_NEW.
156 void ptlrpcd_add_rqset(struct ptlrpc_request_set *set)
158 cfs_list_t *tmp, *pos;
160 struct ptlrpcd_ctl *pc;
161 struct ptlrpc_request_set *new;
164 pc = ptlrpcd_select_pc(NULL, PDL_POLICY_LOCAL, -1);
168 cfs_list_for_each_safe(pos, tmp, &set->set_requests) {
169 struct ptlrpc_request *req =
170 cfs_list_entry(pos, struct ptlrpc_request,
173 LASSERT(req->rq_phase == RQ_PHASE_NEW);
176 req->rq_queued_time = cfs_time_current();
178 cfs_list_del_init(&req->rq_set_chain);
180 ptlrpcd_add_req(req, PDL_POLICY_LOCAL, -1);
181 cfs_atomic_dec(&set->set_remaining);
186 spin_lock(&new->set_new_req_lock);
187 cfs_list_splice_init(&set->set_requests, &new->set_new_requests);
188 i = cfs_atomic_read(&set->set_remaining);
189 count = cfs_atomic_add_return(i, &new->set_new_count);
190 cfs_atomic_set(&set->set_remaining, 0);
191 spin_unlock(&new->set_new_req_lock);
193 cfs_waitq_signal(&new->set_waitq);
195 /* XXX: It maybe unnecessary to wakeup all the partners. But to
196 * guarantee the async RPC can be processed ASAP, we have
197 * no other better choice. It maybe fixed in future. */
198 for (i = 0; i < pc->pc_npartners; i++)
199 cfs_waitq_signal(&pc->pc_partners[i]->pc_set->set_waitq);
203 EXPORT_SYMBOL(ptlrpcd_add_rqset);
207 * Return transferred RPCs count.
209 static int ptlrpcd_steal_rqset(struct ptlrpc_request_set *des,
210 struct ptlrpc_request_set *src)
212 cfs_list_t *tmp, *pos;
213 struct ptlrpc_request *req;
216 spin_lock(&src->set_new_req_lock);
217 if (likely(!cfs_list_empty(&src->set_new_requests))) {
218 cfs_list_for_each_safe(pos, tmp, &src->set_new_requests) {
219 req = cfs_list_entry(pos, struct ptlrpc_request,
223 cfs_list_splice_init(&src->set_new_requests,
225 rc = cfs_atomic_read(&src->set_new_count);
226 cfs_atomic_add(rc, &des->set_remaining);
227 cfs_atomic_set(&src->set_new_count, 0);
229 spin_unlock(&src->set_new_req_lock);
235 * Requests that are added to the ptlrpcd queue are sent via
236 * ptlrpcd_check->ptlrpc_check_set().
238 void ptlrpcd_add_req(struct ptlrpc_request *req, pdl_policy_t policy, int idx)
240 struct ptlrpcd_ctl *pc;
243 lustre_msg_set_jobid(req->rq_reqmsg, NULL);
245 spin_lock(&req->rq_lock);
246 if (req->rq_invalid_rqset) {
247 struct l_wait_info lwi = LWI_TIMEOUT(cfs_time_seconds(5),
248 back_to_sleep, NULL);
250 req->rq_invalid_rqset = 0;
251 spin_unlock(&req->rq_lock);
252 l_wait_event(req->rq_set_waitq, (req->rq_set == NULL), &lwi);
253 } else if (req->rq_set) {
254 /* If we have a vaid "rq_set", just reuse it to avoid double
256 LASSERT(req->rq_phase == RQ_PHASE_NEW);
257 LASSERT(req->rq_send_state == LUSTRE_IMP_REPLAY);
259 /* ptlrpc_check_set will decrease the count */
260 cfs_atomic_inc(&req->rq_set->set_remaining);
261 spin_unlock(&req->rq_lock);
262 cfs_waitq_signal(&req->rq_set->set_waitq);
265 spin_unlock(&req->rq_lock);
268 pc = ptlrpcd_select_pc(req, policy, idx);
270 DEBUG_REQ(D_INFO, req, "add req [%p] to pc [%s:%d]",
271 req, pc->pc_name, pc->pc_index);
273 ptlrpc_set_add_new_req(pc, req);
275 EXPORT_SYMBOL(ptlrpcd_add_req);
277 static inline void ptlrpc_reqset_get(struct ptlrpc_request_set *set)
279 cfs_atomic_inc(&set->set_refcount);
283 * Check if there is more work to do on ptlrpcd set.
286 static int ptlrpcd_check(struct lu_env *env, struct ptlrpcd_ctl *pc)
288 cfs_list_t *tmp, *pos;
289 struct ptlrpc_request *req;
290 struct ptlrpc_request_set *set = pc->pc_set;
295 if (cfs_atomic_read(&set->set_new_count)) {
296 spin_lock(&set->set_new_req_lock);
297 if (likely(!cfs_list_empty(&set->set_new_requests))) {
298 cfs_list_splice_init(&set->set_new_requests,
300 cfs_atomic_add(cfs_atomic_read(&set->set_new_count),
301 &set->set_remaining);
302 cfs_atomic_set(&set->set_new_count, 0);
304 * Need to calculate its timeout.
308 spin_unlock(&set->set_new_req_lock);
311 /* We should call lu_env_refill() before handling new requests to make
312 * sure that env key the requests depending on really exists.
314 rc2 = lu_env_refill(env);
317 * XXX This is very awkward situation, because
318 * execution can neither continue (request
319 * interpreters assume that env is set up), nor repeat
320 * the loop (as this potentially results in a tight
321 * loop of -ENOMEM's).
323 * Fortunately, refill only ever does something when
324 * new modules are loaded, i.e., early during boot up.
326 CERROR("Failure to refill session: %d\n", rc2);
330 if (cfs_atomic_read(&set->set_remaining))
331 rc |= ptlrpc_check_set(env, set);
333 if (!cfs_list_empty(&set->set_requests)) {
335 * XXX: our set never completes, so we prune the completed
336 * reqs after each iteration. boy could this be smarter.
338 cfs_list_for_each_safe(pos, tmp, &set->set_requests) {
339 req = cfs_list_entry(pos, struct ptlrpc_request,
341 if (req->rq_phase != RQ_PHASE_COMPLETE)
344 cfs_list_del_init(&req->rq_set_chain);
346 ptlrpc_req_finished(req);
352 * If new requests have been added, make sure to wake up.
354 rc = cfs_atomic_read(&set->set_new_count);
357 /* If we have nothing to do, check whether we can take some
358 * work from our partner threads. */
359 if (rc == 0 && pc->pc_npartners > 0) {
360 struct ptlrpcd_ctl *partner;
361 struct ptlrpc_request_set *ps;
362 int first = pc->pc_cursor;
365 partner = pc->pc_partners[pc->pc_cursor++];
366 if (pc->pc_cursor >= pc->pc_npartners)
371 spin_lock(&partner->pc_lock);
372 ps = partner->pc_set;
374 spin_unlock(&partner->pc_lock);
378 ptlrpc_reqset_get(ps);
379 spin_unlock(&partner->pc_lock);
381 if (cfs_atomic_read(&ps->set_new_count)) {
382 rc = ptlrpcd_steal_rqset(set, ps);
384 CDEBUG(D_RPCTRACE, "transfer %d"
385 " async RPCs [%d->%d]\n",
386 rc, partner->pc_index,
389 ptlrpc_reqset_put(ps);
390 } while (rc == 0 && pc->pc_cursor != first);
400 * Main ptlrpcd thread.
401 * ptlrpc's code paths like to execute in process context, so we have this
402 * thread which spins on a set which contains the rpcs and sends them.
405 static int ptlrpcd(void *arg)
407 struct ptlrpcd_ctl *pc = arg;
408 struct ptlrpc_request_set *set = pc->pc_set;
409 struct lu_env env = { .le_ses = NULL };
413 cfs_daemonize_ctxt(pc->pc_name);
414 #if defined(CONFIG_SMP) && defined(HAVE_NODE_TO_CPUMASK)
415 if (test_bit(LIOD_BIND, &pc->pc_flags)) {
416 int index = pc->pc_index;
418 if (index >= 0 && index < cfs_num_possible_cpus()) {
419 while (!cpu_online(index)) {
420 if (++index >= cfs_num_possible_cpus())
423 cfs_set_cpus_allowed(cfs_current(),
424 node_to_cpumask(cpu_to_node(index)));
429 * XXX So far only "client" ptlrpcd uses an environment. In
430 * the future, ptlrpcd thread (or a thread-set) has to given
431 * an argument, describing its "scope".
433 rc = lu_context_init(&env.le_ctx,
434 LCT_CL_THREAD|LCT_REMEMBER|LCT_NOREF);
435 complete(&pc->pc_starting);
441 * This mainloop strongly resembles ptlrpc_set_wait() except that our
442 * set never completes. ptlrpcd_check() calls ptlrpc_check_set() when
443 * there are requests in the set. New requests come in on the set's
444 * new_req_list and ptlrpcd_check() moves them into the set.
447 struct l_wait_info lwi;
450 timeout = ptlrpc_set_next_timeout(set);
451 lwi = LWI_TIMEOUT(cfs_time_seconds(timeout ? timeout : 1),
452 ptlrpc_expired_set, set);
454 lu_context_enter(&env.le_ctx);
455 l_wait_event(set->set_waitq,
456 ptlrpcd_check(&env, pc), &lwi);
457 lu_context_exit(&env.le_ctx);
460 * Abort inflight rpcs for forced stop case.
462 if (test_bit(LIOD_STOP, &pc->pc_flags)) {
463 if (test_bit(LIOD_FORCE, &pc->pc_flags))
464 ptlrpc_abort_set(set);
469 * Let's make one more loop to make sure that ptlrpcd_check()
470 * copied all raced new rpcs into the set so we can kill them.
475 * Wait for inflight requests to drain.
477 if (!cfs_list_empty(&set->set_requests))
478 ptlrpc_set_wait(set);
479 lu_context_fini(&env.le_ctx);
481 clear_bit(LIOD_START, &pc->pc_flags);
482 clear_bit(LIOD_STOP, &pc->pc_flags);
483 clear_bit(LIOD_FORCE, &pc->pc_flags);
484 clear_bit(LIOD_BIND, &pc->pc_flags);
486 complete(&pc->pc_finishing);
491 /* XXX: We want multiple CPU cores to share the async RPC load. So we start many
492 * ptlrpcd threads. We also want to reduce the ptlrpcd overhead caused by
493 * data transfer cross-CPU cores. So we bind ptlrpcd thread to specified
494 * CPU core. But binding all ptlrpcd threads maybe cause response delay
495 * because of some CPU core(s) busy with other loads.
497 * For example: "ls -l", some async RPCs for statahead are assigned to
498 * ptlrpcd_0, and ptlrpcd_0 is bound to CPU_0, but CPU_0 may be quite busy
499 * with other non-ptlrpcd, like "ls -l" itself (we want to the "ls -l"
500 * thread, statahead thread, and ptlrpcd thread can run in parallel), under
501 * such case, the statahead async RPCs can not be processed in time, it is
502 * unexpected. If ptlrpcd_0 can be re-scheduled on other CPU core, it may
503 * be better. But it breaks former data transfer policy.
505 * So we shouldn't be blind for avoiding the data transfer. We make some
506 * compromise: divide the ptlrpcd threds pool into two parts. One part is
507 * for bound mode, each ptlrpcd thread in this part is bound to some CPU
508 * core. The other part is for free mode, all the ptlrpcd threads in the
509 * part can be scheduled on any CPU core. We specify some partnership
510 * between bound mode ptlrpcd thread(s) and free mode ptlrpcd thread(s),
511 * and the async RPC load within the partners are shared.
513 * It can partly avoid data transfer cross-CPU (if the bound mode ptlrpcd
514 * thread can be scheduled in time), and try to guarantee the async RPC
515 * processed ASAP (as long as the free mode ptlrpcd thread can be scheduled
518 * As for how to specify the partnership between bound mode ptlrpcd
519 * thread(s) and free mode ptlrpcd thread(s), the simplest way is to use
520 * <free bound> pair. In future, we can specify some more complex
521 * partnership based on the patches for CPU partition. But before such
522 * patches are available, we prefer to use the simplest one.
524 # ifdef CFS_CPU_MODE_NUMA
525 # warning "fix ptlrpcd_bind() to use new CPU partition APIs"
527 static int ptlrpcd_bind(int index, int max)
529 struct ptlrpcd_ctl *pc;
531 #if defined(CONFIG_NUMA) && defined(HAVE_NODE_TO_CPUMASK)
532 struct ptlrpcd_ctl *ppc;
538 LASSERT(index <= max - 1);
539 pc = &ptlrpcds->pd_threads[index];
540 switch (ptlrpcd_bind_policy) {
541 case PDB_POLICY_NONE:
542 pc->pc_npartners = -1;
544 case PDB_POLICY_FULL:
545 pc->pc_npartners = 0;
546 set_bit(LIOD_BIND, &pc->pc_flags);
548 case PDB_POLICY_PAIR:
549 LASSERT(max % 2 == 0);
550 pc->pc_npartners = 1;
552 case PDB_POLICY_NEIGHBOR:
553 #if defined(CONFIG_NUMA) && defined(HAVE_NODE_TO_CPUMASK)
554 node = cpu_to_node(index);
555 mask = node_to_cpumask(node);
556 for (i = max; i < cfs_num_online_cpus(); i++)
558 pc->pc_npartners = cpus_weight(mask) - 1;
559 set_bit(LIOD_BIND, &pc->pc_flags);
562 pc->pc_npartners = 2;
566 CERROR("unknown ptlrpcd bind policy %d\n", ptlrpcd_bind_policy);
570 if (rc == 0 && pc->pc_npartners > 0) {
571 OBD_ALLOC(pc->pc_partners,
572 sizeof(struct ptlrpcd_ctl *) * pc->pc_npartners);
573 if (pc->pc_partners == NULL) {
574 pc->pc_npartners = 0;
577 switch (ptlrpcd_bind_policy) {
578 case PDB_POLICY_PAIR:
580 set_bit(LIOD_BIND, &pc->pc_flags);
581 pc->pc_partners[0] = &ptlrpcds->
582 pd_threads[index - 1];
583 ptlrpcds->pd_threads[index - 1].
587 case PDB_POLICY_NEIGHBOR:
588 #if defined(CONFIG_NUMA) && defined(HAVE_NODE_TO_CPUMASK)
589 /* partners are cores in the same NUMA node.
590 * setup partnership only with ptlrpcd threads
591 * that are already initialized
593 for (pidx = 0, i = 0; i < index; i++) {
594 if (cpu_isset(i, mask)) {
595 ppc = &ptlrpcds->pd_threads[i];
596 pc->pc_partners[pidx++] = ppc;
597 ppc->pc_partners[ppc->
598 pc_npartners++] = pc;
601 /* adjust number of partners to the number
602 * of partnership really setup */
603 pc->pc_npartners = pidx;
606 set_bit(LIOD_BIND, &pc->pc_flags);
608 pc->pc_partners[0] = &ptlrpcds->
609 pd_threads[index - 1];
610 ptlrpcds->pd_threads[index - 1].
612 if (index == max - 1) {
614 &ptlrpcds->pd_threads[0];
615 ptlrpcds->pd_threads[0].
628 #else /* !__KERNEL__ */
631 * In liblustre we do not have separate threads, so this function
632 * is called from time to time all across common code to see
633 * if something needs to be processed on ptlrpcd set.
635 int ptlrpcd_check_async_rpcs(void *arg)
637 struct ptlrpcd_ctl *pc = arg;
645 if (pc->pc_recurred == 1) {
646 rc = lu_env_refill(&pc->pc_env);
648 lu_context_enter(&pc->pc_env.le_ctx);
649 rc = ptlrpcd_check(&pc->pc_env, pc);
651 ptlrpc_expired_set(pc->pc_set);
653 * XXX: send replay requests.
655 if (test_bit(LIOD_RECOVERY, &pc->pc_flags))
656 rc = ptlrpcd_check(&pc->pc_env, pc);
657 lu_context_exit(&pc->pc_env.le_ctx);
665 int ptlrpcd_idle(void *arg)
667 struct ptlrpcd_ctl *pc = arg;
669 return (cfs_atomic_read(&pc->pc_set->set_new_count) == 0 &&
670 cfs_atomic_read(&pc->pc_set->set_remaining) == 0);
675 int ptlrpcd_start(int index, int max, const char *name, struct ptlrpcd_ctl *pc)
682 * Do not allow start second thread for one pc.
684 if (test_and_set_bit(LIOD_START, &pc->pc_flags)) {
685 CWARN("Starting second thread (%s) for same pc %p\n",
690 pc->pc_index = index;
691 init_completion(&pc->pc_starting);
692 init_completion(&pc->pc_finishing);
693 spin_lock_init(&pc->pc_lock);
694 strncpy(pc->pc_name, name, sizeof(pc->pc_name) - 1);
695 pc->pc_set = ptlrpc_prep_set();
696 if (pc->pc_set == NULL)
697 GOTO(out, rc = -ENOMEM);
699 * So far only "client" ptlrpcd uses an environment. In the future,
700 * ptlrpcd thread (or a thread-set) has to be given an argument,
701 * describing its "scope".
703 rc = lu_context_init(&pc->pc_env.le_ctx, LCT_CL_THREAD|LCT_REMEMBER);
710 rc = ptlrpcd_bind(index, max);
715 rc = cfs_create_thread(ptlrpcd, pc, 0);
720 wait_for_completion(&pc->pc_starting);
722 pc->pc_wait_callback =
723 liblustre_register_wait_callback("ptlrpcd_check_async_rpcs",
724 &ptlrpcd_check_async_rpcs, pc);
725 pc->pc_idle_callback =
726 liblustre_register_idle_callback("ptlrpcd_check_idle_rpcs",
732 if (pc->pc_set != NULL) {
733 struct ptlrpc_request_set *set = pc->pc_set;
735 spin_lock(&pc->pc_lock);
737 spin_unlock(&pc->pc_lock);
738 ptlrpc_set_destroy(set);
741 lu_context_fini(&pc->pc_env.le_ctx);
742 clear_bit(LIOD_BIND, &pc->pc_flags);
746 clear_bit(LIOD_START, &pc->pc_flags);
751 void ptlrpcd_stop(struct ptlrpcd_ctl *pc, int force)
753 struct ptlrpc_request_set *set = pc->pc_set;
756 if (!test_bit(LIOD_START, &pc->pc_flags)) {
757 CWARN("Thread for pc %p was not started\n", pc);
761 set_bit(LIOD_STOP, &pc->pc_flags);
763 set_bit(LIOD_FORCE, &pc->pc_flags);
764 cfs_waitq_signal(&pc->pc_set->set_waitq);
766 wait_for_completion(&pc->pc_finishing);
768 liblustre_deregister_wait_callback(pc->pc_wait_callback);
769 liblustre_deregister_idle_callback(pc->pc_idle_callback);
771 lu_context_fini(&pc->pc_env.le_ctx);
773 spin_lock(&pc->pc_lock);
775 spin_unlock(&pc->pc_lock);
776 ptlrpc_set_destroy(set);
780 if (pc->pc_npartners > 0) {
781 LASSERT(pc->pc_partners != NULL);
783 OBD_FREE(pc->pc_partners,
784 sizeof(struct ptlrpcd_ctl *) * pc->pc_npartners);
785 pc->pc_partners = NULL;
787 pc->pc_npartners = 0;
792 static void ptlrpcd_fini(void)
797 if (ptlrpcds != NULL) {
798 for (i = 0; i < ptlrpcds->pd_nthreads; i++)
799 ptlrpcd_stop(&ptlrpcds->pd_threads[i], 0);
800 ptlrpcd_stop(&ptlrpcds->pd_thread_rcv, 0);
801 OBD_FREE(ptlrpcds, ptlrpcds->pd_size);
808 static int ptlrpcd_init(void)
810 int nthreads = cfs_num_online_cpus();
812 int size, i = -1, j, rc = 0;
816 if (max_ptlrpcds > 0 && max_ptlrpcds < nthreads)
817 nthreads = max_ptlrpcds;
820 if (nthreads < 3 && ptlrpcd_bind_policy == PDB_POLICY_NEIGHBOR)
821 ptlrpcd_bind_policy = PDB_POLICY_PAIR;
822 else if (nthreads % 2 != 0 && ptlrpcd_bind_policy == PDB_POLICY_PAIR)
823 nthreads &= ~1; /* make sure it is even */
828 size = offsetof(struct ptlrpcd, pd_threads[nthreads]);
829 OBD_ALLOC(ptlrpcds, size);
830 if (ptlrpcds == NULL)
831 GOTO(out, rc = -ENOMEM);
833 snprintf(name, 15, "ptlrpcd_rcv");
834 set_bit(LIOD_RECOVERY, &ptlrpcds->pd_thread_rcv.pc_flags);
835 rc = ptlrpcd_start(-1, nthreads, name, &ptlrpcds->pd_thread_rcv);
839 /* XXX: We start nthreads ptlrpc daemons. Each of them can process any
840 * non-recovery async RPC to improve overall async RPC efficiency.
842 * But there are some issues with async I/O RPCs and async non-I/O
843 * RPCs processed in the same set under some cases. The ptlrpcd may
844 * be blocked by some async I/O RPC(s), then will cause other async
845 * non-I/O RPC(s) can not be processed in time.
847 * Maybe we should distinguish blocked async RPCs from non-blocked
848 * async RPCs, and process them in different ptlrpcd sets to avoid
849 * unnecessary dependency. But how to distribute async RPCs load
850 * among all the ptlrpc daemons becomes another trouble. */
851 for (i = 0; i < nthreads; i++) {
852 snprintf(name, 15, "ptlrpcd_%d", i);
853 rc = ptlrpcd_start(i, nthreads, name, &ptlrpcds->pd_threads[i]);
858 ptlrpcds->pd_size = size;
859 ptlrpcds->pd_index = 0;
860 ptlrpcds->pd_nthreads = nthreads;
863 if (rc != 0 && ptlrpcds != NULL) {
864 for (j = 0; j <= i; j++)
865 ptlrpcd_stop(&ptlrpcds->pd_threads[j], 0);
866 ptlrpcd_stop(&ptlrpcds->pd_thread_rcv, 0);
867 OBD_FREE(ptlrpcds, size);
874 int ptlrpcd_addref(void)
879 mutex_lock(&ptlrpcd_mutex);
880 if (++ptlrpcd_users == 1)
882 mutex_unlock(&ptlrpcd_mutex);
885 EXPORT_SYMBOL(ptlrpcd_addref);
887 void ptlrpcd_decref(void)
889 mutex_lock(&ptlrpcd_mutex);
890 if (--ptlrpcd_users == 0)
892 mutex_unlock(&ptlrpcd_mutex);
894 EXPORT_SYMBOL(ptlrpcd_decref);