diff options
Diffstat (limited to 'drivers/staging/lustre/lustre/ptlrpc/ptlrpcd.c')
| -rw-r--r-- | drivers/staging/lustre/lustre/ptlrpc/ptlrpcd.c | 827 |
1 files changed, 827 insertions, 0 deletions
diff --git a/drivers/staging/lustre/lustre/ptlrpc/ptlrpcd.c b/drivers/staging/lustre/lustre/ptlrpc/ptlrpcd.c new file mode 100644 index 000000000000..5a66a1be4228 --- /dev/null +++ b/drivers/staging/lustre/lustre/ptlrpc/ptlrpcd.c @@ -0,0 +1,827 @@ +/* + * GPL HEADER START + * + * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 only, + * as published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License version 2 for more details (a copy is included + * in the LICENSE file that accompanied this code). + * + * You should have received a copy of the GNU General Public License + * version 2 along with this program; If not, see + * http://www.sun.com/software/products/lustre/docs/GPLv2.pdf + * + * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, + * CA 95054 USA or visit www.sun.com if you need additional information or + * have any questions. + * + * GPL HEADER END + */ +/* + * Copyright (c) 2003, 2010, Oracle and/or its affiliates. All rights reserved. + * Use is subject to license terms. + * + * Copyright (c) 2011, 2012, Intel Corporation. + */ +/* + * This file is part of Lustre, http://www.lustre.org/ + * Lustre is a trademark of Sun Microsystems, Inc. + * + * lustre/ptlrpc/ptlrpcd.c + */ + +/** \defgroup ptlrpcd PortalRPC daemon + * + * ptlrpcd is a special thread with its own set where other user might add + * requests when they don't want to wait for their completion. + * PtlRPCD will take care of sending such requests and then processing their + * replies and calling completion callbacks as necessary. + * The callbacks are called directly from ptlrpcd context. + * It is important to never significantly block (esp. on RPCs!) within such + * completion handler or a deadlock might occur where ptlrpcd enters some + * callback that attempts to send another RPC and wait for it to return, + * during which time ptlrpcd is completely blocked, so e.g. if import + * fails, recovery cannot progress because connection requests are also + * sent by ptlrpcd. + * + * @{ + */ + +#define DEBUG_SUBSYSTEM S_RPC + +# include <linux/libcfs/libcfs.h> + +#include <lustre_net.h> +# include <lustre_lib.h> + +#include <lustre_ha.h> +#include <obd_class.h> /* for obd_zombie */ +#include <obd_support.h> /* for OBD_FAIL_CHECK */ +#include <cl_object.h> /* cl_env_{get,put}() */ +#include <lprocfs_status.h> + +#include "ptlrpc_internal.h" + +struct ptlrpcd { + int pd_size; + int pd_index; + int pd_nthreads; + struct ptlrpcd_ctl pd_thread_rcv; + struct ptlrpcd_ctl pd_threads[0]; +}; + +static int max_ptlrpcds; +CFS_MODULE_PARM(max_ptlrpcds, "i", int, 0644, + "Max ptlrpcd thread count to be started."); + +static int ptlrpcd_bind_policy = PDB_POLICY_PAIR; +CFS_MODULE_PARM(ptlrpcd_bind_policy, "i", int, 0644, + "Ptlrpcd threads binding mode."); +static struct ptlrpcd *ptlrpcds; + +struct mutex ptlrpcd_mutex; +static int ptlrpcd_users = 0; + +void ptlrpcd_wake(struct ptlrpc_request *req) +{ + struct ptlrpc_request_set *rq_set = req->rq_set; + + LASSERT(rq_set != NULL); + + wake_up(&rq_set->set_waitq); +} +EXPORT_SYMBOL(ptlrpcd_wake); + +static struct ptlrpcd_ctl * +ptlrpcd_select_pc(struct ptlrpc_request *req, pdl_policy_t policy, int index) +{ + int idx = 0; + + if (req != NULL && req->rq_send_state != LUSTRE_IMP_FULL) + return &ptlrpcds->pd_thread_rcv; + + switch (policy) { + case PDL_POLICY_SAME: + idx = smp_processor_id() % ptlrpcds->pd_nthreads; + break; + case PDL_POLICY_LOCAL: + /* Before CPU partition patches available, process it the same + * as "PDL_POLICY_ROUND". */ +# ifdef CFS_CPU_MODE_NUMA +# warning "fix this code to use new CPU partition APIs" +# endif + /* Fall through to PDL_POLICY_ROUND until the CPU + * CPU partition patches are available. */ + index = -1; + case PDL_POLICY_PREFERRED: + if (index >= 0 && index < num_online_cpus()) { + idx = index % ptlrpcds->pd_nthreads; + break; + } + /* Fall through to PDL_POLICY_ROUND for bad index. */ + default: + /* Fall through to PDL_POLICY_ROUND for unknown policy. */ + case PDL_POLICY_ROUND: + /* We do not care whether it is strict load balance. */ + idx = ptlrpcds->pd_index + 1; + if (idx == smp_processor_id()) + idx++; + idx %= ptlrpcds->pd_nthreads; + ptlrpcds->pd_index = idx; + break; + } + + return &ptlrpcds->pd_threads[idx]; +} + +/** + * Move all request from an existing request set to the ptlrpcd queue. + * All requests from the set must be in phase RQ_PHASE_NEW. + */ +void ptlrpcd_add_rqset(struct ptlrpc_request_set *set) +{ + struct list_head *tmp, *pos; + struct ptlrpcd_ctl *pc; + struct ptlrpc_request_set *new; + int count, i; + + pc = ptlrpcd_select_pc(NULL, PDL_POLICY_LOCAL, -1); + new = pc->pc_set; + + list_for_each_safe(pos, tmp, &set->set_requests) { + struct ptlrpc_request *req = + list_entry(pos, struct ptlrpc_request, + rq_set_chain); + + LASSERT(req->rq_phase == RQ_PHASE_NEW); + req->rq_set = new; + req->rq_queued_time = cfs_time_current(); + } + + spin_lock(&new->set_new_req_lock); + list_splice_init(&set->set_requests, &new->set_new_requests); + i = atomic_read(&set->set_remaining); + count = atomic_add_return(i, &new->set_new_count); + atomic_set(&set->set_remaining, 0); + spin_unlock(&new->set_new_req_lock); + if (count == i) { + wake_up(&new->set_waitq); + + /* XXX: It maybe unnecessary to wakeup all the partners. But to + * guarantee the async RPC can be processed ASAP, we have + * no other better choice. It maybe fixed in future. */ + for (i = 0; i < pc->pc_npartners; i++) + wake_up(&pc->pc_partners[i]->pc_set->set_waitq); + } +} +EXPORT_SYMBOL(ptlrpcd_add_rqset); + +/** + * Return transferred RPCs count. + */ +static int ptlrpcd_steal_rqset(struct ptlrpc_request_set *des, + struct ptlrpc_request_set *src) +{ + struct list_head *tmp, *pos; + struct ptlrpc_request *req; + int rc = 0; + + spin_lock(&src->set_new_req_lock); + if (likely(!list_empty(&src->set_new_requests))) { + list_for_each_safe(pos, tmp, &src->set_new_requests) { + req = list_entry(pos, struct ptlrpc_request, + rq_set_chain); + req->rq_set = des; + } + list_splice_init(&src->set_new_requests, + &des->set_requests); + rc = atomic_read(&src->set_new_count); + atomic_add(rc, &des->set_remaining); + atomic_set(&src->set_new_count, 0); + } + spin_unlock(&src->set_new_req_lock); + return rc; +} + +/** + * Requests that are added to the ptlrpcd queue are sent via + * ptlrpcd_check->ptlrpc_check_set(). + */ +void ptlrpcd_add_req(struct ptlrpc_request *req, pdl_policy_t policy, int idx) +{ + struct ptlrpcd_ctl *pc; + + if (req->rq_reqmsg) + lustre_msg_set_jobid(req->rq_reqmsg, NULL); + + spin_lock(&req->rq_lock); + if (req->rq_invalid_rqset) { + struct l_wait_info lwi = LWI_TIMEOUT(cfs_time_seconds(5), + back_to_sleep, NULL); + + req->rq_invalid_rqset = 0; + spin_unlock(&req->rq_lock); + l_wait_event(req->rq_set_waitq, (req->rq_set == NULL), &lwi); + } else if (req->rq_set) { + /* If we have a vaid "rq_set", just reuse it to avoid double + * linked. */ + LASSERT(req->rq_phase == RQ_PHASE_NEW); + LASSERT(req->rq_send_state == LUSTRE_IMP_REPLAY); + + /* ptlrpc_check_set will decrease the count */ + atomic_inc(&req->rq_set->set_remaining); + spin_unlock(&req->rq_lock); + wake_up(&req->rq_set->set_waitq); + return; + } else { + spin_unlock(&req->rq_lock); + } + + pc = ptlrpcd_select_pc(req, policy, idx); + + DEBUG_REQ(D_INFO, req, "add req [%p] to pc [%s:%d]", + req, pc->pc_name, pc->pc_index); + + ptlrpc_set_add_new_req(pc, req); +} +EXPORT_SYMBOL(ptlrpcd_add_req); + +static inline void ptlrpc_reqset_get(struct ptlrpc_request_set *set) +{ + atomic_inc(&set->set_refcount); +} + +/** + * Check if there is more work to do on ptlrpcd set. + * Returns 1 if yes. + */ +static int ptlrpcd_check(struct lu_env *env, struct ptlrpcd_ctl *pc) +{ + struct list_head *tmp, *pos; + struct ptlrpc_request *req; + struct ptlrpc_request_set *set = pc->pc_set; + int rc = 0; + int rc2; + ENTRY; + + if (atomic_read(&set->set_new_count)) { + spin_lock(&set->set_new_req_lock); + if (likely(!list_empty(&set->set_new_requests))) { + list_splice_init(&set->set_new_requests, + &set->set_requests); + atomic_add(atomic_read(&set->set_new_count), + &set->set_remaining); + atomic_set(&set->set_new_count, 0); + /* + * Need to calculate its timeout. + */ + rc = 1; + } + spin_unlock(&set->set_new_req_lock); + } + + /* We should call lu_env_refill() before handling new requests to make + * sure that env key the requests depending on really exists. + */ + rc2 = lu_env_refill(env); + if (rc2 != 0) { + /* + * XXX This is very awkward situation, because + * execution can neither continue (request + * interpreters assume that env is set up), nor repeat + * the loop (as this potentially results in a tight + * loop of -ENOMEM's). + * + * Fortunately, refill only ever does something when + * new modules are loaded, i.e., early during boot up. + */ + CERROR("Failure to refill session: %d\n", rc2); + RETURN(rc); + } + + if (atomic_read(&set->set_remaining)) + rc |= ptlrpc_check_set(env, set); + + if (!list_empty(&set->set_requests)) { + /* + * XXX: our set never completes, so we prune the completed + * reqs after each iteration. boy could this be smarter. + */ + list_for_each_safe(pos, tmp, &set->set_requests) { + req = list_entry(pos, struct ptlrpc_request, + rq_set_chain); + if (req->rq_phase != RQ_PHASE_COMPLETE) + continue; + + list_del_init(&req->rq_set_chain); + req->rq_set = NULL; + ptlrpc_req_finished(req); + } + } + + if (rc == 0) { + /* + * If new requests have been added, make sure to wake up. + */ + rc = atomic_read(&set->set_new_count); + + /* If we have nothing to do, check whether we can take some + * work from our partner threads. */ + if (rc == 0 && pc->pc_npartners > 0) { + struct ptlrpcd_ctl *partner; + struct ptlrpc_request_set *ps; + int first = pc->pc_cursor; + + do { + partner = pc->pc_partners[pc->pc_cursor++]; + if (pc->pc_cursor >= pc->pc_npartners) + pc->pc_cursor = 0; + if (partner == NULL) + continue; + + spin_lock(&partner->pc_lock); + ps = partner->pc_set; + if (ps == NULL) { + spin_unlock(&partner->pc_lock); + continue; + } + + ptlrpc_reqset_get(ps); + spin_unlock(&partner->pc_lock); + + if (atomic_read(&ps->set_new_count)) { + rc = ptlrpcd_steal_rqset(set, ps); + if (rc > 0) + CDEBUG(D_RPCTRACE, "transfer %d" + " async RPCs [%d->%d]\n", + rc, partner->pc_index, + pc->pc_index); + } + ptlrpc_reqset_put(ps); + } while (rc == 0 && pc->pc_cursor != first); + } + } + + RETURN(rc); +} + +/** + * Main ptlrpcd thread. + * ptlrpc's code paths like to execute in process context, so we have this + * thread which spins on a set which contains the rpcs and sends them. + * + */ +static int ptlrpcd(void *arg) +{ + struct ptlrpcd_ctl *pc = arg; + struct ptlrpc_request_set *set = pc->pc_set; + struct lu_env env = { .le_ses = NULL }; + int rc, exit = 0; + ENTRY; + + unshare_fs_struct(); +#if defined(CONFIG_SMP) + if (test_bit(LIOD_BIND, &pc->pc_flags)) { + int index = pc->pc_index; + + if (index >= 0 && index < num_possible_cpus()) { + while (!cpu_online(index)) { + if (++index >= num_possible_cpus()) + index = 0; + } + set_cpus_allowed_ptr(current, + cpumask_of_node(cpu_to_node(index))); + } + } +#endif + /* + * XXX So far only "client" ptlrpcd uses an environment. In + * the future, ptlrpcd thread (or a thread-set) has to given + * an argument, describing its "scope". + */ + rc = lu_context_init(&env.le_ctx, + LCT_CL_THREAD|LCT_REMEMBER|LCT_NOREF); + complete(&pc->pc_starting); + + if (rc != 0) + RETURN(rc); + + /* + * This mainloop strongly resembles ptlrpc_set_wait() except that our + * set never completes. ptlrpcd_check() calls ptlrpc_check_set() when + * there are requests in the set. New requests come in on the set's + * new_req_list and ptlrpcd_check() moves them into the set. + */ + do { + struct l_wait_info lwi; + int timeout; + + timeout = ptlrpc_set_next_timeout(set); + lwi = LWI_TIMEOUT(cfs_time_seconds(timeout ? timeout : 1), + ptlrpc_expired_set, set); + + lu_context_enter(&env.le_ctx); + l_wait_event(set->set_waitq, + ptlrpcd_check(&env, pc), &lwi); + lu_context_exit(&env.le_ctx); + + /* + * Abort inflight rpcs for forced stop case. + */ + if (test_bit(LIOD_STOP, &pc->pc_flags)) { + if (test_bit(LIOD_FORCE, &pc->pc_flags)) + ptlrpc_abort_set(set); + exit++; + } + + /* + * Let's make one more loop to make sure that ptlrpcd_check() + * copied all raced new rpcs into the set so we can kill them. + */ + } while (exit < 2); + + /* + * Wait for inflight requests to drain. + */ + if (!list_empty(&set->set_requests)) + ptlrpc_set_wait(set); + lu_context_fini(&env.le_ctx); + + complete(&pc->pc_finishing); + + return 0; +} + +/* XXX: We want multiple CPU cores to share the async RPC load. So we start many + * ptlrpcd threads. We also want to reduce the ptlrpcd overhead caused by + * data transfer cross-CPU cores. So we bind ptlrpcd thread to specified + * CPU core. But binding all ptlrpcd threads maybe cause response delay + * because of some CPU core(s) busy with other loads. + * + * For example: "ls -l", some async RPCs for statahead are assigned to + * ptlrpcd_0, and ptlrpcd_0 is bound to CPU_0, but CPU_0 may be quite busy + * with other non-ptlrpcd, like "ls -l" itself (we want to the "ls -l" + * thread, statahead thread, and ptlrpcd thread can run in parallel), under + * such case, the statahead async RPCs can not be processed in time, it is + * unexpected. If ptlrpcd_0 can be re-scheduled on other CPU core, it may + * be better. But it breaks former data transfer policy. + * + * So we shouldn't be blind for avoiding the data transfer. We make some + * compromise: divide the ptlrpcd threds pool into two parts. One part is + * for bound mode, each ptlrpcd thread in this part is bound to some CPU + * core. The other part is for free mode, all the ptlrpcd threads in the + * part can be scheduled on any CPU core. We specify some partnership + * between bound mode ptlrpcd thread(s) and free mode ptlrpcd thread(s), + * and the async RPC load within the partners are shared. + * + * It can partly avoid data transfer cross-CPU (if the bound mode ptlrpcd + * thread can be scheduled in time), and try to guarantee the async RPC + * processed ASAP (as long as the free mode ptlrpcd thread can be scheduled + * on any CPU core). + * + * As for how to specify the partnership between bound mode ptlrpcd + * thread(s) and free mode ptlrpcd thread(s), the simplest way is to use + * <free bound> pair. In future, we can specify some more complex + * partnership based on the patches for CPU partition. But before such + * patches are available, we prefer to use the simplest one. + */ +# ifdef CFS_CPU_MODE_NUMA +# warning "fix ptlrpcd_bind() to use new CPU partition APIs" +# endif +static int ptlrpcd_bind(int index, int max) +{ + struct ptlrpcd_ctl *pc; + int rc = 0; +#if defined(CONFIG_NUMA) + cpumask_t mask; +#endif + ENTRY; + + LASSERT(index <= max - 1); + pc = &ptlrpcds->pd_threads[index]; + switch (ptlrpcd_bind_policy) { + case PDB_POLICY_NONE: + pc->pc_npartners = -1; + break; + case PDB_POLICY_FULL: + pc->pc_npartners = 0; + set_bit(LIOD_BIND, &pc->pc_flags); + break; + case PDB_POLICY_PAIR: + LASSERT(max % 2 == 0); + pc->pc_npartners = 1; + break; + case PDB_POLICY_NEIGHBOR: +#if defined(CONFIG_NUMA) + { + int i; + mask = *cpumask_of_node(cpu_to_node(index)); + for (i = max; i < num_online_cpus(); i++) + cpu_clear(i, mask); + pc->pc_npartners = cpus_weight(mask) - 1; + set_bit(LIOD_BIND, &pc->pc_flags); + } +#else + LASSERT(max >= 3); + pc->pc_npartners = 2; +#endif + break; + default: + CERROR("unknown ptlrpcd bind policy %d\n", ptlrpcd_bind_policy); + rc = -EINVAL; + } + + if (rc == 0 && pc->pc_npartners > 0) { + OBD_ALLOC(pc->pc_partners, + sizeof(struct ptlrpcd_ctl *) * pc->pc_npartners); + if (pc->pc_partners == NULL) { + pc->pc_npartners = 0; + rc = -ENOMEM; + } else { + switch (ptlrpcd_bind_policy) { + case PDB_POLICY_PAIR: + if (index & 0x1) { + set_bit(LIOD_BIND, &pc->pc_flags); + pc->pc_partners[0] = &ptlrpcds-> + pd_threads[index - 1]; + ptlrpcds->pd_threads[index - 1]. + pc_partners[0] = pc; + } + break; + case PDB_POLICY_NEIGHBOR: +#if defined(CONFIG_NUMA) + { + struct ptlrpcd_ctl *ppc; + int i, pidx; + /* partners are cores in the same NUMA node. + * setup partnership only with ptlrpcd threads + * that are already initialized + */ + for (pidx = 0, i = 0; i < index; i++) { + if (cpu_isset(i, mask)) { + ppc = &ptlrpcds->pd_threads[i]; + pc->pc_partners[pidx++] = ppc; + ppc->pc_partners[ppc-> + pc_npartners++] = pc; + } + } + /* adjust number of partners to the number + * of partnership really setup */ + pc->pc_npartners = pidx; + } +#else + if (index & 0x1) + set_bit(LIOD_BIND, &pc->pc_flags); + if (index > 0) { + pc->pc_partners[0] = &ptlrpcds-> + pd_threads[index - 1]; + ptlrpcds->pd_threads[index - 1]. + pc_partners[1] = pc; + if (index == max - 1) { + pc->pc_partners[1] = + &ptlrpcds->pd_threads[0]; + ptlrpcds->pd_threads[0]. + pc_partners[0] = pc; + } + } +#endif + break; + } + } + } + + RETURN(rc); +} + + +int ptlrpcd_start(int index, int max, const char *name, struct ptlrpcd_ctl *pc) +{ + int rc; + int env = 0; + ENTRY; + + /* + * Do not allow start second thread for one pc. + */ + if (test_and_set_bit(LIOD_START, &pc->pc_flags)) { + CWARN("Starting second thread (%s) for same pc %p\n", + name, pc); + RETURN(0); + } + + pc->pc_index = index; + init_completion(&pc->pc_starting); + init_completion(&pc->pc_finishing); + spin_lock_init(&pc->pc_lock); + strncpy(pc->pc_name, name, sizeof(pc->pc_name) - 1); + pc->pc_set = ptlrpc_prep_set(); + if (pc->pc_set == NULL) + GOTO(out, rc = -ENOMEM); + /* + * So far only "client" ptlrpcd uses an environment. In the future, + * ptlrpcd thread (or a thread-set) has to be given an argument, + * describing its "scope". + */ + rc = lu_context_init(&pc->pc_env.le_ctx, LCT_CL_THREAD|LCT_REMEMBER); + if (rc != 0) + GOTO(out, rc); + + env = 1; + { + task_t *task; + if (index >= 0) { + rc = ptlrpcd_bind(index, max); + if (rc < 0) + GOTO(out, rc); + } + + task = kthread_run(ptlrpcd, pc, pc->pc_name); + if (IS_ERR(task)) + GOTO(out, rc = PTR_ERR(task)); + + rc = 0; + wait_for_completion(&pc->pc_starting); + } +out: + if (rc) { + if (pc->pc_set != NULL) { + struct ptlrpc_request_set *set = pc->pc_set; + + spin_lock(&pc->pc_lock); + pc->pc_set = NULL; + spin_unlock(&pc->pc_lock); + ptlrpc_set_destroy(set); + } + if (env != 0) + lu_context_fini(&pc->pc_env.le_ctx); + clear_bit(LIOD_BIND, &pc->pc_flags); + clear_bit(LIOD_START, &pc->pc_flags); + } + RETURN(rc); +} + +void ptlrpcd_stop(struct ptlrpcd_ctl *pc, int force) +{ + ENTRY; + + if (!test_bit(LIOD_START, &pc->pc_flags)) { + CWARN("Thread for pc %p was not started\n", pc); + goto out; + } + + set_bit(LIOD_STOP, &pc->pc_flags); + if (force) + set_bit(LIOD_FORCE, &pc->pc_flags); + wake_up(&pc->pc_set->set_waitq); + +out: + EXIT; +} + +void ptlrpcd_free(struct ptlrpcd_ctl *pc) +{ + struct ptlrpc_request_set *set = pc->pc_set; + ENTRY; + + if (!test_bit(LIOD_START, &pc->pc_flags)) { + CWARN("Thread for pc %p was not started\n", pc); + goto out; + } + + wait_for_completion(&pc->pc_finishing); + lu_context_fini(&pc->pc_env.le_ctx); + + spin_lock(&pc->pc_lock); + pc->pc_set = NULL; + spin_unlock(&pc->pc_lock); + ptlrpc_set_destroy(set); + + clear_bit(LIOD_START, &pc->pc_flags); + clear_bit(LIOD_STOP, &pc->pc_flags); + clear_bit(LIOD_FORCE, &pc->pc_flags); + clear_bit(LIOD_BIND, &pc->pc_flags); + +out: + if (pc->pc_npartners > 0) { + LASSERT(pc->pc_partners != NULL); + + OBD_FREE(pc->pc_partners, + sizeof(struct ptlrpcd_ctl *) * pc->pc_npartners); + pc->pc_partners = NULL; + } + pc->pc_npartners = 0; + EXIT; +} + +static void ptlrpcd_fini(void) +{ + int i; + ENTRY; + + if (ptlrpcds != NULL) { + for (i = 0; i < ptlrpcds->pd_nthreads; i++) + ptlrpcd_stop(&ptlrpcds->pd_threads[i], 0); + for (i = 0; i < ptlrpcds->pd_nthreads; i++) + ptlrpcd_free(&ptlrpcds->pd_threads[i]); + ptlrpcd_stop(&ptlrpcds->pd_thread_rcv, 0); + ptlrpcd_free(&ptlrpcds->pd_thread_rcv); + OBD_FREE(ptlrpcds, ptlrpcds->pd_size); + ptlrpcds = NULL; + } + + EXIT; +} + +static int ptlrpcd_init(void) +{ + int nthreads = num_online_cpus(); + char name[16]; + int size, i = -1, j, rc = 0; + ENTRY; + + if (max_ptlrpcds > 0 && max_ptlrpcds < nthreads) + nthreads = max_ptlrpcds; + if (nthreads < 2) + nthreads = 2; + if (nthreads < 3 && ptlrpcd_bind_policy == PDB_POLICY_NEIGHBOR) + ptlrpcd_bind_policy = PDB_POLICY_PAIR; + else if (nthreads % 2 != 0 && ptlrpcd_bind_policy == PDB_POLICY_PAIR) + nthreads &= ~1; /* make sure it is even */ + + size = offsetof(struct ptlrpcd, pd_threads[nthreads]); + OBD_ALLOC(ptlrpcds, size); + if (ptlrpcds == NULL) + GOTO(out, rc = -ENOMEM); + + snprintf(name, 15, "ptlrpcd_rcv"); + set_bit(LIOD_RECOVERY, &ptlrpcds->pd_thread_rcv.pc_flags); + rc = ptlrpcd_start(-1, nthreads, name, &ptlrpcds->pd_thread_rcv); + if (rc < 0) + GOTO(out, rc); + + /* XXX: We start nthreads ptlrpc daemons. Each of them can process any + * non-recovery async RPC to improve overall async RPC efficiency. + * + * But there are some issues with async I/O RPCs and async non-I/O + * RPCs processed in the same set under some cases. The ptlrpcd may + * be blocked by some async I/O RPC(s), then will cause other async + * non-I/O RPC(s) can not be processed in time. + * + * Maybe we should distinguish blocked async RPCs from non-blocked + * async RPCs, and process them in different ptlrpcd sets to avoid + * unnecessary dependency. But how to distribute async RPCs load + * among all the ptlrpc daemons becomes another trouble. */ + for (i = 0; i < nthreads; i++) { + snprintf(name, 15, "ptlrpcd_%d", i); + rc = ptlrpcd_start(i, nthreads, name, &ptlrpcds->pd_threads[i]); + if (rc < 0) + GOTO(out, rc); + } + + ptlrpcds->pd_size = size; + ptlrpcds->pd_index = 0; + ptlrpcds->pd_nthreads = nthreads; + +out: + if (rc != 0 && ptlrpcds != NULL) { + for (j = 0; j <= i; j++) + ptlrpcd_stop(&ptlrpcds->pd_threads[j], 0); + for (j = 0; j <= i; j++) + ptlrpcd_free(&ptlrpcds->pd_threads[j]); + ptlrpcd_stop(&ptlrpcds->pd_thread_rcv, 0); + ptlrpcd_free(&ptlrpcds->pd_thread_rcv); + OBD_FREE(ptlrpcds, size); + ptlrpcds = NULL; + } + + RETURN(0); +} + +int ptlrpcd_addref(void) +{ + int rc = 0; + ENTRY; + + mutex_lock(&ptlrpcd_mutex); + if (++ptlrpcd_users == 1) + rc = ptlrpcd_init(); + mutex_unlock(&ptlrpcd_mutex); + RETURN(rc); +} +EXPORT_SYMBOL(ptlrpcd_addref); + +void ptlrpcd_decref(void) +{ + mutex_lock(&ptlrpcd_mutex); + if (--ptlrpcd_users == 0) + ptlrpcd_fini(); + mutex_unlock(&ptlrpcd_mutex); +} +EXPORT_SYMBOL(ptlrpcd_decref); +/** @} ptlrpcd */ |