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,
8 * as published by the Free Software Foundation.
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.gnu.org/licenses/gpl-2.0.html
23 * Copyright (c) 2003, 2010, Oracle and/or its affiliates. All rights reserved.
24 * Use is subject to license terms.
26 * Copyright (c) 2011, 2017, Intel Corporation.
29 * This file is part of Lustre, http://www.lustre.org/
30 * Lustre is a trademark of Sun Microsystems, Inc.
32 * lustre/ptlrpc/ptlrpcd.c
35 /** \defgroup ptlrpcd PortalRPC daemon
37 * ptlrpcd is a special thread with its own set where other user might add
38 * requests when they don't want to wait for their completion.
39 * PtlRPCD will take care of sending such requests and then processing their
40 * replies and calling completion callbacks as necessary.
41 * The callbacks are called directly from ptlrpcd context.
42 * It is important to never significantly block (esp. on RPCs!) within such
43 * completion handler or a deadlock might occur where ptlrpcd enters some
44 * callback that attempts to send another RPC and wait for it to return,
45 * during which time ptlrpcd is completely blocked, so e.g. if import
46 * fails, recovery cannot progress because connection requests are also
52 #define DEBUG_SUBSYSTEM S_RPC
54 #include <linux/kthread.h>
55 #include <libcfs/libcfs.h>
56 #include <lustre_net.h>
57 #include <lustre_lib.h>
58 #include <lustre_ha.h>
59 #include <obd_class.h> /* for obd_zombie */
60 #include <obd_support.h> /* for OBD_FAIL_CHECK */
61 #include <cl_object.h> /* cl_env_{get,put}() */
62 #include <lprocfs_status.h>
64 #include "ptlrpc_internal.h"
66 /* One of these per CPT. */
74 struct ptlrpcd_ctl pd_threads[0];
78 * max_ptlrpcds is obsolete, but retained to ensure that the kernel
79 * module will load on a system where it has been tuned.
80 * A value other than 0 implies it was tuned, in which case the value
81 * is used to derive a setting for ptlrpcd_per_cpt_max.
83 static int max_ptlrpcds;
84 module_param(max_ptlrpcds, int, 0644);
85 MODULE_PARM_DESC(max_ptlrpcds,
86 "Max ptlrpcd thread count to be started (obsolete).");
89 * ptlrpcd_bind_policy is obsolete, but retained to ensure that
90 * the kernel module will load on a system where it has been tuned.
91 * A value other than 0 implies it was tuned, in which case the value
92 * is used to derive a setting for ptlrpcd_partner_group_size.
94 static int ptlrpcd_bind_policy;
95 module_param(ptlrpcd_bind_policy, int, 0644);
96 MODULE_PARM_DESC(ptlrpcd_bind_policy,
97 "Ptlrpcd threads binding mode (obsolete).");
100 * ptlrpcd_per_cpt_max: The maximum number of ptlrpcd threads to run
103 static int ptlrpcd_per_cpt_max;
104 module_param(ptlrpcd_per_cpt_max, int, 0644);
105 MODULE_PARM_DESC(ptlrpcd_per_cpt_max,
106 "Max ptlrpcd thread count to be started per CPT.");
109 * ptlrpcd_partner_group_size: The desired number of threads in each
110 * ptlrpcd partner thread group. Default is 2, corresponding to the
111 * old PDB_POLICY_PAIR. A negative value makes all ptlrpcd threads in
112 * a CPT partners of each other.
114 static int ptlrpcd_partner_group_size;
115 module_param(ptlrpcd_partner_group_size, int, 0644);
116 MODULE_PARM_DESC(ptlrpcd_partner_group_size,
117 "Number of ptlrpcd threads in a partner group.");
120 * ptlrpcd_cpts: A CPT string describing the CPU partitions that
121 * ptlrpcd threads should run on. Used to make ptlrpcd threads run on
122 * a subset of all CPTs.
126 * run ptlrpcd threads only on CPT 2.
130 * run ptlrpcd threads on CPTs 0, 1, 2, and 3.
132 * ptlrpcd_cpts=[0-3,5,7]
133 * run ptlrpcd threads on CPTS 0, 1, 2, 3, 5, and 7.
135 static char *ptlrpcd_cpts;
136 module_param(ptlrpcd_cpts, charp, 0644);
137 MODULE_PARM_DESC(ptlrpcd_cpts,
138 "CPU partitions ptlrpcd threads should run in");
140 /* ptlrpcds_cpt_idx maps cpt numbers to an index in the ptlrpcds array. */
141 static int *ptlrpcds_cpt_idx;
143 /* ptlrpcds_num is the number of entries in the ptlrpcds array. */
144 static int ptlrpcds_num;
145 static struct ptlrpcd **ptlrpcds;
148 * In addition to the regular thread pool above, there is a single
149 * global recovery thread. Recovery isn't critical for performance,
150 * and doesn't block, but must always be able to proceed, and it is
151 * possible that all normal ptlrpcd threads are blocked. Hence the
152 * need for a dedicated thread.
154 static struct ptlrpcd_ctl ptlrpcd_rcv;
156 struct mutex ptlrpcd_mutex;
157 static int ptlrpcd_users = 0;
159 void ptlrpcd_wake(struct ptlrpc_request *req)
161 struct ptlrpc_request_set *set = req->rq_set;
163 LASSERT(set != NULL);
164 wake_up(&set->set_waitq);
166 EXPORT_SYMBOL(ptlrpcd_wake);
168 static struct ptlrpcd_ctl *
169 ptlrpcd_select_pc(struct ptlrpc_request *req)
175 if (req != NULL && req->rq_send_state != LUSTRE_IMP_FULL)
178 cpt = cfs_cpt_current(cfs_cpt_tab, 1);
179 if (ptlrpcds_cpt_idx == NULL)
182 idx = ptlrpcds_cpt_idx[cpt];
185 /* We do not care whether it is strict load balance. */
187 if (++idx == pd->pd_nthreads)
191 return &pd->pd_threads[idx];
195 * Move all request from an existing request set to the ptlrpcd queue.
196 * All requests from the set must be in phase RQ_PHASE_NEW.
198 void ptlrpcd_add_rqset(struct ptlrpc_request_set *set)
200 struct list_head *tmp, *pos;
201 struct ptlrpcd_ctl *pc;
202 struct ptlrpc_request_set *new;
205 pc = ptlrpcd_select_pc(NULL);
208 list_for_each_safe(pos, tmp, &set->set_requests) {
209 struct ptlrpc_request *req =
210 list_entry(pos, struct ptlrpc_request,
213 LASSERT(req->rq_phase == RQ_PHASE_NEW);
215 req->rq_queued_time = ktime_get_seconds();
218 spin_lock(&new->set_new_req_lock);
219 list_splice_init(&set->set_requests, &new->set_new_requests);
220 i = atomic_read(&set->set_remaining);
221 count = atomic_add_return(i, &new->set_new_count);
222 atomic_set(&set->set_remaining, 0);
223 spin_unlock(&new->set_new_req_lock);
225 wake_up(&new->set_waitq);
228 * XXX: It maybe unnecessary to wakeup all the partners. But to
229 * guarantee the async RPC can be processed ASAP, we have
230 * no other better choice. It maybe fixed in future.
232 for (i = 0; i < pc->pc_npartners; i++)
233 wake_up(&pc->pc_partners[i]->pc_set->set_waitq);
238 * Return transferred RPCs count.
240 static int ptlrpcd_steal_rqset(struct ptlrpc_request_set *des,
241 struct ptlrpc_request_set *src)
243 struct list_head *tmp, *pos;
244 struct ptlrpc_request *req;
247 spin_lock(&src->set_new_req_lock);
248 if (likely(!list_empty(&src->set_new_requests))) {
249 list_for_each_safe(pos, tmp, &src->set_new_requests) {
250 req = list_entry(pos, struct ptlrpc_request,
254 list_splice_init(&src->set_new_requests,
256 rc = atomic_read(&src->set_new_count);
257 atomic_add(rc, &des->set_remaining);
258 atomic_set(&src->set_new_count, 0);
260 spin_unlock(&src->set_new_req_lock);
265 * Requests that are added to the ptlrpcd queue are sent via
266 * ptlrpcd_check->ptlrpc_check_set().
268 void ptlrpcd_add_req(struct ptlrpc_request *req)
270 struct ptlrpcd_ctl *pc;
273 lustre_msg_set_jobid(req->rq_reqmsg, NULL);
275 spin_lock(&req->rq_lock);
276 if (req->rq_invalid_rqset) {
277 req->rq_invalid_rqset = 0;
278 spin_unlock(&req->rq_lock);
279 if (wait_event_idle_timeout(req->rq_set_waitq,
281 cfs_time_seconds(5)) == 0)
282 l_wait_event_abortable(req->rq_set_waitq,
283 req->rq_set == NULL);
284 } else if (req->rq_set) {
286 * If we have a vaid "rq_set", just reuse it to avoid double
289 LASSERT(req->rq_phase == RQ_PHASE_NEW);
290 LASSERT(req->rq_send_state == LUSTRE_IMP_REPLAY);
292 /* ptlrpc_check_set will decrease the count */
293 atomic_inc(&req->rq_set->set_remaining);
294 spin_unlock(&req->rq_lock);
295 wake_up(&req->rq_set->set_waitq);
298 spin_unlock(&req->rq_lock);
301 pc = ptlrpcd_select_pc(req);
303 DEBUG_REQ(D_INFO, req, "add req [%p] to pc [%s+%d]",
304 req, pc->pc_name, pc->pc_index);
306 ptlrpc_set_add_new_req(pc, req);
308 EXPORT_SYMBOL(ptlrpcd_add_req);
310 static inline void ptlrpc_reqset_get(struct ptlrpc_request_set *set)
312 atomic_inc(&set->set_refcount);
316 * Check if there is more work to do on ptlrpcd set.
319 static int ptlrpcd_check(struct lu_env *env, struct ptlrpcd_ctl *pc)
321 struct list_head *tmp, *pos;
322 struct ptlrpc_request *req;
323 struct ptlrpc_request_set *set = pc->pc_set;
329 if (atomic_read(&set->set_new_count)) {
330 spin_lock(&set->set_new_req_lock);
331 if (likely(!list_empty(&set->set_new_requests))) {
332 list_splice_init(&set->set_new_requests,
334 atomic_add(atomic_read(&set->set_new_count),
335 &set->set_remaining);
336 atomic_set(&set->set_new_count, 0);
338 * Need to calculate its timeout.
342 spin_unlock(&set->set_new_req_lock);
346 * We should call lu_env_refill() before handling new requests to make
347 * sure that env key the requests depending on really exists.
349 rc2 = lu_env_refill(env);
352 * XXX This is very awkward situation, because
353 * execution can neither continue (request
354 * interpreters assume that env is set up), nor repeat
355 * the loop (as this potentially results in a tight
356 * loop of -ENOMEM's).
358 * Fortunately, refill only ever does something when
359 * new modules are loaded, i.e., early during boot up.
361 CERROR("Failure to refill session: %d\n", rc2);
365 if (atomic_read(&set->set_remaining))
366 rc |= ptlrpc_check_set(env, set);
369 * NB: ptlrpc_check_set has already moved complted request at the
370 * head of seq::set_requests
372 list_for_each_safe(pos, tmp, &set->set_requests) {
373 req = list_entry(pos, struct ptlrpc_request, rq_set_chain);
374 if (req->rq_phase != RQ_PHASE_COMPLETE)
377 list_del_init(&req->rq_set_chain);
379 ptlrpc_req_finished(req);
384 * If new requests have been added, make sure to wake up.
386 rc = atomic_read(&set->set_new_count);
389 * If we have nothing to do, check whether we can take some
390 * work from our partner threads.
392 if (rc == 0 && pc->pc_npartners > 0) {
393 struct ptlrpcd_ctl *partner;
394 struct ptlrpc_request_set *ps;
395 int first = pc->pc_cursor;
398 partner = pc->pc_partners[pc->pc_cursor++];
399 if (pc->pc_cursor >= pc->pc_npartners)
404 spin_lock(&partner->pc_lock);
405 ps = partner->pc_set;
407 spin_unlock(&partner->pc_lock);
411 ptlrpc_reqset_get(ps);
412 spin_unlock(&partner->pc_lock);
414 if (atomic_read(&ps->set_new_count)) {
415 rc = ptlrpcd_steal_rqset(set, ps);
418 "transfer %d async RPCs [%d->%d]\n",
419 rc, partner->pc_index,
422 ptlrpc_reqset_put(ps);
423 } while (rc == 0 && pc->pc_cursor != first);
427 RETURN(rc || test_bit(LIOD_STOP, &pc->pc_flags));
431 * Main ptlrpcd thread.
432 * ptlrpc's code paths like to execute in process context, so we have this
433 * thread which spins on a set which contains the rpcs and sends them.
435 static int ptlrpcd(void *arg)
437 struct ptlrpcd_ctl *pc = arg;
438 struct ptlrpc_request_set *set;
439 struct lu_context ses = { 0 };
440 struct lu_env env = { .le_ses = &ses };
445 if (cfs_cpt_bind(cfs_cpt_tab, pc->pc_cpt) != 0)
446 CWARN("Failed to bind %s on CPT %d\n", pc->pc_name, pc->pc_cpt);
449 * Allocate the request set after the thread has been bound
450 * above. This is safe because no requests will be queued
451 * until all ptlrpcd threads have confirmed that they have
452 * successfully started.
454 set = ptlrpc_prep_set();
456 GOTO(failed, rc = -ENOMEM);
457 spin_lock(&pc->pc_lock);
459 spin_unlock(&pc->pc_lock);
461 /* Both client and server (MDT/OST) may use the environment. */
462 rc = lu_context_init(&env.le_ctx, LCT_MD_THREAD |
469 rc = lu_context_init(env.le_ses, LCT_SESSION |
473 lu_context_fini(&env.le_ctx);
477 complete(&pc->pc_starting);
480 * This mainloop strongly resembles ptlrpc_set_wait() except that our
481 * set never completes. ptlrpcd_check() calls ptlrpc_check_set() when
482 * there are requests in the set. New requests come in on the set's
483 * new_req_list and ptlrpcd_check() moves them into the set.
488 timeout = ptlrpc_set_next_timeout(set);
490 lu_context_enter(&env.le_ctx);
491 lu_context_enter(env.le_ses);
493 wait_event_idle(set->set_waitq,
494 ptlrpcd_check(&env, pc));
495 else if (wait_event_idle_timeout(set->set_waitq,
496 ptlrpcd_check(&env, pc),
497 cfs_time_seconds(timeout))
499 ptlrpc_expired_set(set);
500 lu_context_exit(&env.le_ctx);
501 lu_context_exit(env.le_ses);
504 * Abort inflight rpcs for forced stop case.
506 if (test_bit(LIOD_STOP, &pc->pc_flags)) {
507 if (test_bit(LIOD_FORCE, &pc->pc_flags))
508 ptlrpc_abort_set(set);
513 * Let's make one more loop to make sure that ptlrpcd_check()
514 * copied all raced new rpcs into the set so we can kill them.
519 * Wait for inflight requests to drain.
521 if (!list_empty(&set->set_requests))
522 ptlrpc_set_wait(&env, set);
523 lu_context_fini(&env.le_ctx);
524 lu_context_fini(env.le_ses);
526 complete(&pc->pc_finishing);
532 complete(&pc->pc_starting);
536 static void ptlrpcd_ctl_init(struct ptlrpcd_ctl *pc, int index, int cpt)
540 pc->pc_index = index;
542 init_completion(&pc->pc_starting);
543 init_completion(&pc->pc_finishing);
544 spin_lock_init(&pc->pc_lock);
547 /* Recovery thread. */
548 snprintf(pc->pc_name, sizeof(pc->pc_name), "ptlrpcd_rcv");
550 /* Regular thread. */
551 snprintf(pc->pc_name, sizeof(pc->pc_name),
552 "ptlrpcd_%02d_%02d", cpt, index);
558 /* XXX: We want multiple CPU cores to share the async RPC load. So we
559 * start many ptlrpcd threads. We also want to reduce the ptlrpcd
560 * overhead caused by data transfer cross-CPU cores. So we bind
561 * all ptlrpcd threads to a CPT, in the expectation that CPTs
562 * will be defined in a way that matches these boundaries. Within
563 * a CPT a ptlrpcd thread can be scheduled on any available core.
565 * Each ptlrpcd thread has its own request queue. This can cause
566 * response delay if the thread is already busy. To help with
567 * this we define partner threads: these are other threads bound
568 * to the same CPT which will check for work in each other's
569 * request queues if they have no work to do.
571 * The desired number of partner threads can be tuned by setting
572 * ptlrpcd_partner_group_size. The default is to create pairs of
575 static int ptlrpcd_partners(struct ptlrpcd *pd, int index)
577 struct ptlrpcd_ctl *pc;
578 struct ptlrpcd_ctl **ppc;
585 LASSERT(index >= 0 && index < pd->pd_nthreads);
586 pc = &pd->pd_threads[index];
587 pc->pc_npartners = pd->pd_groupsize - 1;
589 if (pc->pc_npartners <= 0)
592 OBD_CPT_ALLOC(pc->pc_partners, cfs_cpt_tab, pc->pc_cpt,
593 sizeof(struct ptlrpcd_ctl *) * pc->pc_npartners);
594 if (pc->pc_partners == NULL) {
595 pc->pc_npartners = 0;
596 GOTO(out, rc = -ENOMEM);
599 first = index - index % pd->pd_groupsize;
600 ppc = pc->pc_partners;
601 for (i = first; i < first + pd->pd_groupsize; i++) {
603 *ppc++ = &pd->pd_threads[i];
609 int ptlrpcd_start(struct ptlrpcd_ctl *pc)
611 struct task_struct *task;
617 * Do not allow starting a second thread for one pc.
619 if (test_and_set_bit(LIOD_START, &pc->pc_flags)) {
620 CWARN("Starting second thread (%s) for same pc %p\n",
625 task = kthread_run(ptlrpcd, pc, "%s", pc->pc_name);
627 GOTO(out_set, rc = PTR_ERR(task));
629 wait_for_completion(&pc->pc_starting);
637 if (pc->pc_set != NULL) {
638 struct ptlrpc_request_set *set = pc->pc_set;
640 spin_lock(&pc->pc_lock);
642 spin_unlock(&pc->pc_lock);
643 ptlrpc_set_destroy(set);
645 clear_bit(LIOD_START, &pc->pc_flags);
649 void ptlrpcd_stop(struct ptlrpcd_ctl *pc, int force)
653 if (!test_bit(LIOD_START, &pc->pc_flags)) {
654 CWARN("Thread for pc %p was not started\n", pc);
658 set_bit(LIOD_STOP, &pc->pc_flags);
660 set_bit(LIOD_FORCE, &pc->pc_flags);
661 wake_up(&pc->pc_set->set_waitq);
667 void ptlrpcd_free(struct ptlrpcd_ctl *pc)
669 struct ptlrpc_request_set *set = pc->pc_set;
673 if (!test_bit(LIOD_START, &pc->pc_flags)) {
674 CWARN("Thread for pc %p was not started\n", pc);
678 wait_for_completion(&pc->pc_finishing);
680 spin_lock(&pc->pc_lock);
682 spin_unlock(&pc->pc_lock);
683 ptlrpc_set_destroy(set);
685 clear_bit(LIOD_START, &pc->pc_flags);
686 clear_bit(LIOD_STOP, &pc->pc_flags);
687 clear_bit(LIOD_FORCE, &pc->pc_flags);
690 if (pc->pc_npartners > 0) {
691 LASSERT(pc->pc_partners != NULL);
693 OBD_FREE_PTR_ARRAY(pc->pc_partners, pc->pc_npartners);
694 pc->pc_partners = NULL;
696 pc->pc_npartners = 0;
701 static void ptlrpcd_fini(void)
709 if (ptlrpcds != NULL) {
710 for (i = 0; i < ptlrpcds_num; i++) {
711 if (ptlrpcds[i] == NULL)
713 for (j = 0; j < ptlrpcds[i]->pd_nthreads; j++)
714 ptlrpcd_stop(&ptlrpcds[i]->pd_threads[j], 0);
715 for (j = 0; j < ptlrpcds[i]->pd_nthreads; j++)
716 ptlrpcd_free(&ptlrpcds[i]->pd_threads[j]);
717 OBD_FREE(ptlrpcds[i], ptlrpcds[i]->pd_size);
720 OBD_FREE_PTR_ARRAY(ptlrpcds, ptlrpcds_num);
724 ptlrpcd_stop(&ptlrpcd_rcv, 0);
725 ptlrpcd_free(&ptlrpcd_rcv);
727 if (ptlrpcds_cpt_idx != NULL) {
728 ncpts = cfs_cpt_number(cfs_cpt_tab);
729 OBD_FREE_PTR_ARRAY(ptlrpcds_cpt_idx, ncpts);
730 ptlrpcds_cpt_idx = NULL;
736 static int ptlrpcd_init(void)
744 struct cfs_cpt_table *cptable;
753 * Determine the CPTs that ptlrpcd threads will run on.
755 cptable = cfs_cpt_tab;
756 ncpts = cfs_cpt_number(cptable);
757 if (ptlrpcd_cpts != NULL) {
758 struct cfs_expr_list *el;
760 size = ncpts * sizeof(ptlrpcds_cpt_idx[0]);
761 OBD_ALLOC(ptlrpcds_cpt_idx, size);
762 if (ptlrpcds_cpt_idx == NULL)
763 GOTO(out, rc = -ENOMEM);
765 rc = cfs_expr_list_parse(ptlrpcd_cpts,
766 strlen(ptlrpcd_cpts),
769 CERROR("%s: invalid CPT pattern string: %s",
770 "ptlrpcd_cpts", ptlrpcd_cpts);
771 GOTO(out, rc = -EINVAL);
774 rc = cfs_expr_list_values(el, ncpts, &cpts);
775 cfs_expr_list_free(el);
777 CERROR("%s: failed to parse CPT array %s: %d\n",
778 "ptlrpcd_cpts", ptlrpcd_cpts, rc);
785 * Create the cpt-to-index map. When there is no match
786 * in the cpt table, pick a cpt at random. This could
787 * be changed to take the topology of the system into
790 for (cpt = 0; cpt < ncpts; cpt++) {
791 for (i = 0; i < rc; i++)
796 ptlrpcds_cpt_idx[cpt] = i;
799 cfs_expr_list_values_free(cpts, rc);
802 ptlrpcds_num = ncpts;
804 size = ncpts * sizeof(ptlrpcds[0]);
805 OBD_ALLOC(ptlrpcds, size);
806 if (ptlrpcds == NULL)
807 GOTO(out, rc = -ENOMEM);
810 * The max_ptlrpcds parameter is obsolete, but do something
811 * sane if it has been tuned, and complain if
812 * ptlrpcd_per_cpt_max has also been tuned.
814 if (max_ptlrpcds != 0) {
815 CWARN("max_ptlrpcds is obsolete.\n");
816 if (ptlrpcd_per_cpt_max == 0) {
817 ptlrpcd_per_cpt_max = max_ptlrpcds / ncpts;
818 /* Round up if there is a remainder. */
819 if (max_ptlrpcds % ncpts != 0)
820 ptlrpcd_per_cpt_max++;
821 CWARN("Setting ptlrpcd_per_cpt_max = %d\n",
822 ptlrpcd_per_cpt_max);
824 CWARN("ptlrpd_per_cpt_max is also set!\n");
829 * The ptlrpcd_bind_policy parameter is obsolete, but do
830 * something sane if it has been tuned, and complain if
831 * ptlrpcd_partner_group_size is also tuned.
833 if (ptlrpcd_bind_policy != 0) {
834 CWARN("ptlrpcd_bind_policy is obsolete.\n");
835 if (ptlrpcd_partner_group_size == 0) {
836 switch (ptlrpcd_bind_policy) {
837 case 1: /* PDB_POLICY_NONE */
838 case 2: /* PDB_POLICY_FULL */
839 ptlrpcd_partner_group_size = 1;
841 case 3: /* PDB_POLICY_PAIR */
842 ptlrpcd_partner_group_size = 2;
844 case 4: /* PDB_POLICY_NEIGHBOR */
846 ptlrpcd_partner_group_size = -1; /* CPT */
848 ptlrpcd_partner_group_size = 3; /* Triplets */
851 default: /* Illegal value, use the default. */
852 ptlrpcd_partner_group_size = 2;
855 CWARN("Setting ptlrpcd_partner_group_size = %d\n",
856 ptlrpcd_partner_group_size);
858 CWARN("ptlrpcd_partner_group_size is also set!\n");
862 if (ptlrpcd_partner_group_size == 0)
863 ptlrpcd_partner_group_size = 2;
864 else if (ptlrpcd_partner_group_size < 0)
865 ptlrpcd_partner_group_size = -1;
866 else if (ptlrpcd_per_cpt_max > 0 &&
867 ptlrpcd_partner_group_size > ptlrpcd_per_cpt_max)
868 ptlrpcd_partner_group_size = ptlrpcd_per_cpt_max;
871 * Start the recovery thread first.
873 set_bit(LIOD_RECOVERY, &ptlrpcd_rcv.pc_flags);
874 ptlrpcd_ctl_init(&ptlrpcd_rcv, -1, CFS_CPT_ANY);
875 rc = ptlrpcd_start(&ptlrpcd_rcv);
879 for (i = 0; i < ncpts; i++) {
885 nthreads = cfs_cpt_weight(cptable, cpt);
886 if (ptlrpcd_per_cpt_max > 0 && ptlrpcd_per_cpt_max < nthreads)
887 nthreads = ptlrpcd_per_cpt_max;
891 if (ptlrpcd_partner_group_size <= 0) {
892 groupsize = nthreads;
893 } else if (nthreads <= ptlrpcd_partner_group_size) {
894 groupsize = nthreads;
896 groupsize = ptlrpcd_partner_group_size;
897 if (nthreads % groupsize != 0)
898 nthreads += groupsize - (nthreads % groupsize);
901 size = offsetof(struct ptlrpcd, pd_threads[nthreads]);
902 OBD_CPT_ALLOC(pd, cptable, cpt, size);
905 GOTO(out, rc = -ENOMEM);
910 pd->pd_nthreads = nthreads;
911 pd->pd_groupsize = groupsize;
915 * The ptlrpcd threads in a partner group can access
916 * each other's struct ptlrpcd_ctl, so these must be
917 * initialized before any thead is started.
919 for (j = 0; j < nthreads; j++) {
920 ptlrpcd_ctl_init(&pd->pd_threads[j], j, cpt);
921 rc = ptlrpcd_partners(pd, j);
926 /* XXX: We start nthreads ptlrpc daemons on this cpt.
927 * Each of them can process any non-recovery
928 * async RPC to improve overall async RPC
931 * But there are some issues with async I/O RPCs
932 * and async non-I/O RPCs processed in the same
933 * set under some cases. The ptlrpcd may be
934 * blocked by some async I/O RPC(s), then will
935 * cause other async non-I/O RPC(s) can not be
938 * Maybe we should distinguish blocked async RPCs
939 * from non-blocked async RPCs, and process them
940 * in different ptlrpcd sets to avoid unnecessary
941 * dependency. But how to distribute async RPCs
942 * load among all the ptlrpc daemons becomes
945 for (j = 0; j < nthreads; j++) {
946 rc = ptlrpcd_start(&pd->pd_threads[j]);
958 int ptlrpcd_addref(void)
964 mutex_lock(&ptlrpcd_mutex);
965 if (++ptlrpcd_users == 1) {
970 mutex_unlock(&ptlrpcd_mutex);
973 EXPORT_SYMBOL(ptlrpcd_addref);
975 void ptlrpcd_decref(void)
977 mutex_lock(&ptlrpcd_mutex);
978 if (--ptlrpcd_users == 0)
980 mutex_unlock(&ptlrpcd_mutex);
982 EXPORT_SYMBOL(ptlrpcd_decref);