diff options
Diffstat (limited to 'drivers/staging/lustre/lustre/ptlrpc/pinger.c')
| -rw-r--r-- | drivers/staging/lustre/lustre/ptlrpc/pinger.c | 763 |
1 files changed, 763 insertions, 0 deletions
diff --git a/drivers/staging/lustre/lustre/ptlrpc/pinger.c b/drivers/staging/lustre/lustre/ptlrpc/pinger.c new file mode 100644 index 000000000000..ef5269aee0de --- /dev/null +++ b/drivers/staging/lustre/lustre/ptlrpc/pinger.c @@ -0,0 +1,763 @@ +/* + * 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/pinger.c + * + * Portal-RPC reconnection and replay operations, for use in recovery. + */ + +#define DEBUG_SUBSYSTEM S_RPC + +#include <obd_support.h> +#include <obd_class.h> +#include "ptlrpc_internal.h" + +static int suppress_pings; +CFS_MODULE_PARM(suppress_pings, "i", int, 0644, "Suppress pings"); + +struct mutex pinger_mutex; +static LIST_HEAD(pinger_imports); +static struct list_head timeout_list = LIST_HEAD_INIT(timeout_list); + +int ptlrpc_pinger_suppress_pings() +{ + return suppress_pings; +} +EXPORT_SYMBOL(ptlrpc_pinger_suppress_pings); + +struct ptlrpc_request * +ptlrpc_prep_ping(struct obd_import *imp) +{ + struct ptlrpc_request *req; + + req = ptlrpc_request_alloc_pack(imp, &RQF_OBD_PING, + LUSTRE_OBD_VERSION, OBD_PING); + if (req) { + ptlrpc_request_set_replen(req); + req->rq_no_resend = req->rq_no_delay = 1; + } + return req; +} + +int ptlrpc_obd_ping(struct obd_device *obd) +{ + int rc; + struct ptlrpc_request *req; + ENTRY; + + req = ptlrpc_prep_ping(obd->u.cli.cl_import); + if (req == NULL) + RETURN(-ENOMEM); + + req->rq_send_state = LUSTRE_IMP_FULL; + + rc = ptlrpc_queue_wait(req); + + ptlrpc_req_finished(req); + + RETURN(rc); +} +EXPORT_SYMBOL(ptlrpc_obd_ping); + +int ptlrpc_ping(struct obd_import *imp) +{ + struct ptlrpc_request *req; + ENTRY; + + req = ptlrpc_prep_ping(imp); + if (req == NULL) { + CERROR("OOM trying to ping %s->%s\n", + imp->imp_obd->obd_uuid.uuid, + obd2cli_tgt(imp->imp_obd)); + RETURN(-ENOMEM); + } + + DEBUG_REQ(D_INFO, req, "pinging %s->%s", + imp->imp_obd->obd_uuid.uuid, obd2cli_tgt(imp->imp_obd)); + ptlrpcd_add_req(req, PDL_POLICY_ROUND, -1); + + RETURN(0); +} + +void ptlrpc_update_next_ping(struct obd_import *imp, int soon) +{ + int time = soon ? PING_INTERVAL_SHORT : PING_INTERVAL; + if (imp->imp_state == LUSTRE_IMP_DISCON) { + int dtime = max_t(int, CONNECTION_SWITCH_MIN, + AT_OFF ? 0 : + at_get(&imp->imp_at.iat_net_latency)); + time = min(time, dtime); + } + imp->imp_next_ping = cfs_time_shift(time); +} + +void ptlrpc_ping_import_soon(struct obd_import *imp) +{ + imp->imp_next_ping = cfs_time_current(); +} + +static inline int imp_is_deactive(struct obd_import *imp) +{ + return (imp->imp_deactive || + OBD_FAIL_CHECK(OBD_FAIL_PTLRPC_IMP_DEACTIVE)); +} + +static inline int ptlrpc_next_reconnect(struct obd_import *imp) +{ + if (imp->imp_server_timeout) + return cfs_time_shift(obd_timeout / 2); + else + return cfs_time_shift(obd_timeout); +} + +static atomic_t suspend_timeouts = ATOMIC_INIT(0); +static cfs_time_t suspend_wakeup_time = 0; + +cfs_duration_t pinger_check_timeout(cfs_time_t time) +{ + struct timeout_item *item; + cfs_time_t timeout = PING_INTERVAL; + + /* The timeout list is a increase order sorted list */ + mutex_lock(&pinger_mutex); + list_for_each_entry(item, &timeout_list, ti_chain) { + int ti_timeout = item->ti_timeout; + if (timeout > ti_timeout) + timeout = ti_timeout; + break; + } + mutex_unlock(&pinger_mutex); + + return cfs_time_sub(cfs_time_add(time, cfs_time_seconds(timeout)), + cfs_time_current()); +} + +static wait_queue_head_t suspend_timeouts_waitq; + +cfs_time_t ptlrpc_suspend_wakeup_time(void) +{ + return suspend_wakeup_time; +} + +void ptlrpc_deactivate_timeouts(struct obd_import *imp) +{ + /*XXX: disabled for now, will be replaced by adaptive timeouts */ +#if 0 + if (imp->imp_no_timeout) + return; + imp->imp_no_timeout = 1; + atomic_inc(&suspend_timeouts); + CDEBUG(D_HA|D_WARNING, "deactivate timeouts %u\n", + atomic_read(&suspend_timeouts)); +#endif +} + +void ptlrpc_activate_timeouts(struct obd_import *imp) +{ + /*XXX: disabled for now, will be replaced by adaptive timeouts */ +#if 0 + if (!imp->imp_no_timeout) + return; + imp->imp_no_timeout = 0; + LASSERT(atomic_read(&suspend_timeouts) > 0); + if (atomic_dec_and_test(&suspend_timeouts)) { + suspend_wakeup_time = cfs_time_current(); + wake_up(&suspend_timeouts_waitq); + } + CDEBUG(D_HA|D_WARNING, "activate timeouts %u\n", + atomic_read(&suspend_timeouts)); +#endif +} + +int ptlrpc_check_suspend(void) +{ + if (atomic_read(&suspend_timeouts)) + return 1; + return 0; +} + +int ptlrpc_check_and_wait_suspend(struct ptlrpc_request *req) +{ + struct l_wait_info lwi; + + if (atomic_read(&suspend_timeouts)) { + DEBUG_REQ(D_NET, req, "-- suspend %d regular timeout", + atomic_read(&suspend_timeouts)); + lwi = LWI_INTR(NULL, NULL); + l_wait_event(suspend_timeouts_waitq, + atomic_read(&suspend_timeouts) == 0, &lwi); + DEBUG_REQ(D_NET, req, "-- recharge regular timeout"); + return 1; + } + return 0; +} + + +static bool ir_up; + +void ptlrpc_pinger_ir_up(void) +{ + CDEBUG(D_HA, "IR up\n"); + ir_up = true; +} +EXPORT_SYMBOL(ptlrpc_pinger_ir_up); + +void ptlrpc_pinger_ir_down(void) +{ + CDEBUG(D_HA, "IR down\n"); + ir_up = false; +} +EXPORT_SYMBOL(ptlrpc_pinger_ir_down); + +static void ptlrpc_pinger_process_import(struct obd_import *imp, + unsigned long this_ping) +{ + int level; + int force; + int force_next; + int suppress; + + spin_lock(&imp->imp_lock); + + level = imp->imp_state; + force = imp->imp_force_verify; + force_next = imp->imp_force_next_verify; + /* + * This will be used below only if the import is "FULL". + */ + suppress = ir_up && OCD_HAS_FLAG(&imp->imp_connect_data, PINGLESS); + + imp->imp_force_verify = 0; + + if (cfs_time_aftereq(imp->imp_next_ping - 5 * CFS_TICK, this_ping) && + !force) { + spin_unlock(&imp->imp_lock); + return; + } + + imp->imp_force_next_verify = 0; + + spin_unlock(&imp->imp_lock); + + CDEBUG(level == LUSTRE_IMP_FULL ? D_INFO : D_HA, "%s->%s: level %s/%u " + "force %u force_next %u deactive %u pingable %u suppress %u\n", + imp->imp_obd->obd_uuid.uuid, obd2cli_tgt(imp->imp_obd), + ptlrpc_import_state_name(level), level, force, force_next, + imp->imp_deactive, imp->imp_pingable, suppress); + + if (level == LUSTRE_IMP_DISCON && !imp_is_deactive(imp)) { + /* wait for a while before trying recovery again */ + imp->imp_next_ping = ptlrpc_next_reconnect(imp); + if (!imp->imp_no_pinger_recover) + ptlrpc_initiate_recovery(imp); + } else if (level != LUSTRE_IMP_FULL || + imp->imp_obd->obd_no_recov || + imp_is_deactive(imp)) { + CDEBUG(D_HA, "%s->%s: not pinging (in recovery " + "or recovery disabled: %s)\n", + imp->imp_obd->obd_uuid.uuid, obd2cli_tgt(imp->imp_obd), + ptlrpc_import_state_name(level)); + } else if ((imp->imp_pingable && !suppress) || force_next || force) { + ptlrpc_ping(imp); + } +} + +static int ptlrpc_pinger_main(void *arg) +{ + struct ptlrpc_thread *thread = (struct ptlrpc_thread *)arg; + ENTRY; + + /* Record that the thread is running */ + thread_set_flags(thread, SVC_RUNNING); + wake_up(&thread->t_ctl_waitq); + + /* And now, loop forever, pinging as needed. */ + while (1) { + cfs_time_t this_ping = cfs_time_current(); + struct l_wait_info lwi; + cfs_duration_t time_to_next_wake; + struct timeout_item *item; + struct list_head *iter; + + mutex_lock(&pinger_mutex); + list_for_each_entry(item, &timeout_list, ti_chain) { + item->ti_cb(item, item->ti_cb_data); + } + list_for_each(iter, &pinger_imports) { + struct obd_import *imp = + list_entry(iter, struct obd_import, + imp_pinger_chain); + + ptlrpc_pinger_process_import(imp, this_ping); + /* obd_timeout might have changed */ + if (imp->imp_pingable && imp->imp_next_ping && + cfs_time_after(imp->imp_next_ping, + cfs_time_add(this_ping, + cfs_time_seconds(PING_INTERVAL)))) + ptlrpc_update_next_ping(imp, 0); + } + mutex_unlock(&pinger_mutex); + /* update memory usage info */ + obd_update_maxusage(); + + /* Wait until the next ping time, or until we're stopped. */ + time_to_next_wake = pinger_check_timeout(this_ping); + /* The ping sent by ptlrpc_send_rpc may get sent out + say .01 second after this. + ptlrpc_pinger_sending_on_import will then set the + next ping time to next_ping + .01 sec, which means + we will SKIP the next ping at next_ping, and the + ping will get sent 2 timeouts from now! Beware. */ + CDEBUG(D_INFO, "next wakeup in "CFS_DURATION_T" (" + CFS_TIME_T")\n", time_to_next_wake, + cfs_time_add(this_ping,cfs_time_seconds(PING_INTERVAL))); + if (time_to_next_wake > 0) { + lwi = LWI_TIMEOUT(max_t(cfs_duration_t, + time_to_next_wake, + cfs_time_seconds(1)), + NULL, NULL); + l_wait_event(thread->t_ctl_waitq, + thread_is_stopping(thread) || + thread_is_event(thread), + &lwi); + if (thread_test_and_clear_flags(thread, SVC_STOPPING)) { + EXIT; + break; + } else { + /* woken after adding import to reset timer */ + thread_test_and_clear_flags(thread, SVC_EVENT); + } + } + } + + thread_set_flags(thread, SVC_STOPPED); + wake_up(&thread->t_ctl_waitq); + + CDEBUG(D_NET, "pinger thread exiting, process %d\n", current_pid()); + return 0; +} + +static struct ptlrpc_thread *pinger_thread = NULL; + +int ptlrpc_start_pinger(void) +{ + struct l_wait_info lwi = { 0 }; + int rc; + ENTRY; + + if (pinger_thread != NULL) + RETURN(-EALREADY); + + OBD_ALLOC_PTR(pinger_thread); + if (pinger_thread == NULL) + RETURN(-ENOMEM); + init_waitqueue_head(&pinger_thread->t_ctl_waitq); + init_waitqueue_head(&suspend_timeouts_waitq); + + strcpy(pinger_thread->t_name, "ll_ping"); + + /* CLONE_VM and CLONE_FILES just avoid a needless copy, because we + * just drop the VM and FILES in cfs_daemonize_ctxt() right away. */ + rc = PTR_ERR(kthread_run(ptlrpc_pinger_main, + pinger_thread, pinger_thread->t_name)); + if (IS_ERR_VALUE(rc)) { + CERROR("cannot start thread: %d\n", rc); + OBD_FREE(pinger_thread, sizeof(*pinger_thread)); + pinger_thread = NULL; + RETURN(rc); + } + l_wait_event(pinger_thread->t_ctl_waitq, + thread_is_running(pinger_thread), &lwi); + + if (suppress_pings) + CWARN("Pings will be suppressed at the request of the " + "administrator. The configuration shall meet the " + "additional requirements described in the manual. " + "(Search for the \"suppress_pings\" kernel module " + "parameter.)\n"); + + RETURN(0); +} + +int ptlrpc_pinger_remove_timeouts(void); + +int ptlrpc_stop_pinger(void) +{ + struct l_wait_info lwi = { 0 }; + int rc = 0; + ENTRY; + + if (pinger_thread == NULL) + RETURN(-EALREADY); + + ptlrpc_pinger_remove_timeouts(); + mutex_lock(&pinger_mutex); + thread_set_flags(pinger_thread, SVC_STOPPING); + wake_up(&pinger_thread->t_ctl_waitq); + mutex_unlock(&pinger_mutex); + + l_wait_event(pinger_thread->t_ctl_waitq, + thread_is_stopped(pinger_thread), &lwi); + + OBD_FREE_PTR(pinger_thread); + pinger_thread = NULL; + RETURN(rc); +} + +void ptlrpc_pinger_sending_on_import(struct obd_import *imp) +{ + ptlrpc_update_next_ping(imp, 0); +} +EXPORT_SYMBOL(ptlrpc_pinger_sending_on_import); + +void ptlrpc_pinger_commit_expected(struct obd_import *imp) +{ + ptlrpc_update_next_ping(imp, 1); + LASSERT(spin_is_locked(&imp->imp_lock)); + /* + * Avoid reading stale imp_connect_data. When not sure if pings are + * expected or not on next connection, we assume they are not and force + * one anyway to guarantee the chance of updating + * imp_peer_committed_transno. + */ + if (imp->imp_state != LUSTRE_IMP_FULL || + OCD_HAS_FLAG(&imp->imp_connect_data, PINGLESS)) + imp->imp_force_next_verify = 1; +} + +int ptlrpc_pinger_add_import(struct obd_import *imp) +{ + ENTRY; + if (!list_empty(&imp->imp_pinger_chain)) + RETURN(-EALREADY); + + mutex_lock(&pinger_mutex); + CDEBUG(D_HA, "adding pingable import %s->%s\n", + imp->imp_obd->obd_uuid.uuid, obd2cli_tgt(imp->imp_obd)); + /* if we add to pinger we want recovery on this import */ + imp->imp_obd->obd_no_recov = 0; + ptlrpc_update_next_ping(imp, 0); + /* XXX sort, blah blah */ + list_add_tail(&imp->imp_pinger_chain, &pinger_imports); + class_import_get(imp); + + ptlrpc_pinger_wake_up(); + mutex_unlock(&pinger_mutex); + + RETURN(0); +} +EXPORT_SYMBOL(ptlrpc_pinger_add_import); + +int ptlrpc_pinger_del_import(struct obd_import *imp) +{ + ENTRY; + if (list_empty(&imp->imp_pinger_chain)) + RETURN(-ENOENT); + + mutex_lock(&pinger_mutex); + list_del_init(&imp->imp_pinger_chain); + CDEBUG(D_HA, "removing pingable import %s->%s\n", + imp->imp_obd->obd_uuid.uuid, obd2cli_tgt(imp->imp_obd)); + /* if we remove from pinger we don't want recovery on this import */ + imp->imp_obd->obd_no_recov = 1; + class_import_put(imp); + mutex_unlock(&pinger_mutex); + RETURN(0); +} +EXPORT_SYMBOL(ptlrpc_pinger_del_import); + +/** + * Register a timeout callback to the pinger list, and the callback will + * be called when timeout happens. + */ +struct timeout_item* ptlrpc_new_timeout(int time, enum timeout_event event, + timeout_cb_t cb, void *data) +{ + struct timeout_item *ti; + + OBD_ALLOC_PTR(ti); + if (!ti) + return(NULL); + + INIT_LIST_HEAD(&ti->ti_obd_list); + INIT_LIST_HEAD(&ti->ti_chain); + ti->ti_timeout = time; + ti->ti_event = event; + ti->ti_cb = cb; + ti->ti_cb_data = data; + + return ti; +} + +/** + * Register timeout event on the the pinger thread. + * Note: the timeout list is an sorted list with increased timeout value. + */ +static struct timeout_item* +ptlrpc_pinger_register_timeout(int time, enum timeout_event event, + timeout_cb_t cb, void *data) +{ + struct timeout_item *item, *tmp; + + LASSERT(mutex_is_locked(&pinger_mutex)); + + list_for_each_entry(item, &timeout_list, ti_chain) + if (item->ti_event == event) + goto out; + + item = ptlrpc_new_timeout(time, event, cb, data); + if (item) { + list_for_each_entry_reverse(tmp, &timeout_list, ti_chain) { + if (tmp->ti_timeout < time) { + list_add(&item->ti_chain, &tmp->ti_chain); + goto out; + } + } + list_add(&item->ti_chain, &timeout_list); + } +out: + return item; +} + +/* Add a client_obd to the timeout event list, when timeout(@time) + * happens, the callback(@cb) will be called. + */ +int ptlrpc_add_timeout_client(int time, enum timeout_event event, + timeout_cb_t cb, void *data, + struct list_head *obd_list) +{ + struct timeout_item *ti; + + mutex_lock(&pinger_mutex); + ti = ptlrpc_pinger_register_timeout(time, event, cb, data); + if (!ti) { + mutex_unlock(&pinger_mutex); + return (-EINVAL); + } + list_add(obd_list, &ti->ti_obd_list); + mutex_unlock(&pinger_mutex); + return 0; +} +EXPORT_SYMBOL(ptlrpc_add_timeout_client); + +int ptlrpc_del_timeout_client(struct list_head *obd_list, + enum timeout_event event) +{ + struct timeout_item *ti = NULL, *item; + + if (list_empty(obd_list)) + return 0; + mutex_lock(&pinger_mutex); + list_del_init(obd_list); + /** + * If there are no obd attached to the timeout event + * list, remove this timeout event from the pinger + */ + list_for_each_entry(item, &timeout_list, ti_chain) { + if (item->ti_event == event) { + ti = item; + break; + } + } + LASSERTF(ti != NULL, "ti is NULL ! \n"); + if (list_empty(&ti->ti_obd_list)) { + list_del(&ti->ti_chain); + OBD_FREE_PTR(ti); + } + mutex_unlock(&pinger_mutex); + return 0; +} +EXPORT_SYMBOL(ptlrpc_del_timeout_client); + +int ptlrpc_pinger_remove_timeouts(void) +{ + struct timeout_item *item, *tmp; + + mutex_lock(&pinger_mutex); + list_for_each_entry_safe(item, tmp, &timeout_list, ti_chain) { + LASSERT(list_empty(&item->ti_obd_list)); + list_del(&item->ti_chain); + OBD_FREE_PTR(item); + } + mutex_unlock(&pinger_mutex); + return 0; +} + +void ptlrpc_pinger_wake_up() +{ + thread_add_flags(pinger_thread, SVC_EVENT); + wake_up(&pinger_thread->t_ctl_waitq); +} + +/* Ping evictor thread */ +#define PET_READY 1 +#define PET_TERMINATE 2 + +static int pet_refcount = 0; +static int pet_state; +static wait_queue_head_t pet_waitq; +LIST_HEAD(pet_list); +static DEFINE_SPINLOCK(pet_lock); + +int ping_evictor_wake(struct obd_export *exp) +{ + struct obd_device *obd; + + spin_lock(&pet_lock); + if (pet_state != PET_READY) { + /* eventually the new obd will call here again. */ + spin_unlock(&pet_lock); + return 1; + } + + obd = class_exp2obd(exp); + if (list_empty(&obd->obd_evict_list)) { + class_incref(obd, "evictor", obd); + list_add(&obd->obd_evict_list, &pet_list); + } + spin_unlock(&pet_lock); + + wake_up(&pet_waitq); + return 0; +} + +static int ping_evictor_main(void *arg) +{ + struct obd_device *obd; + struct obd_export *exp; + struct l_wait_info lwi = { 0 }; + time_t expire_time; + ENTRY; + + unshare_fs_struct(); + + CDEBUG(D_HA, "Starting Ping Evictor\n"); + pet_state = PET_READY; + while (1) { + l_wait_event(pet_waitq, (!list_empty(&pet_list)) || + (pet_state == PET_TERMINATE), &lwi); + + /* loop until all obd's will be removed */ + if ((pet_state == PET_TERMINATE) && list_empty(&pet_list)) + break; + + /* we only get here if pet_exp != NULL, and the end of this + * loop is the only place which sets it NULL again, so lock + * is not strictly necessary. */ + spin_lock(&pet_lock); + obd = list_entry(pet_list.next, struct obd_device, + obd_evict_list); + spin_unlock(&pet_lock); + + expire_time = cfs_time_current_sec() - PING_EVICT_TIMEOUT; + + CDEBUG(D_HA, "evicting all exports of obd %s older than %ld\n", + obd->obd_name, expire_time); + + /* Exports can't be deleted out of the list while we hold + * the obd lock (class_unlink_export), which means we can't + * lose the last ref on the export. If they've already been + * removed from the list, we won't find them here. */ + spin_lock(&obd->obd_dev_lock); + while (!list_empty(&obd->obd_exports_timed)) { + exp = list_entry(obd->obd_exports_timed.next, + struct obd_export, + exp_obd_chain_timed); + if (expire_time > exp->exp_last_request_time) { + class_export_get(exp); + spin_unlock(&obd->obd_dev_lock); + LCONSOLE_WARN("%s: haven't heard from client %s" + " (at %s) in %ld seconds. I think" + " it's dead, and I am evicting" + " it. exp %p, cur %ld expire %ld" + " last %ld\n", + obd->obd_name, + obd_uuid2str(&exp->exp_client_uuid), + obd_export_nid2str(exp), + (long)(cfs_time_current_sec() - + exp->exp_last_request_time), + exp, (long)cfs_time_current_sec(), + (long)expire_time, + (long)exp->exp_last_request_time); + CDEBUG(D_HA, "Last request was at %ld\n", + exp->exp_last_request_time); + class_fail_export(exp); + class_export_put(exp); + spin_lock(&obd->obd_dev_lock); + } else { + /* List is sorted, so everyone below is ok */ + break; + } + } + spin_unlock(&obd->obd_dev_lock); + + spin_lock(&pet_lock); + list_del_init(&obd->obd_evict_list); + spin_unlock(&pet_lock); + + class_decref(obd, "evictor", obd); + } + CDEBUG(D_HA, "Exiting Ping Evictor\n"); + + RETURN(0); +} + +void ping_evictor_start(void) +{ + task_t *task; + + if (++pet_refcount > 1) + return; + + init_waitqueue_head(&pet_waitq); + + task = kthread_run(ping_evictor_main, NULL, "ll_evictor"); + if (IS_ERR(task)) { + pet_refcount--; + CERROR("Cannot start ping evictor thread: %ld\n", + PTR_ERR(task)); + } +} +EXPORT_SYMBOL(ping_evictor_start); + +void ping_evictor_stop(void) +{ + if (--pet_refcount > 0) + return; + + pet_state = PET_TERMINATE; + wake_up(&pet_waitq); +} +EXPORT_SYMBOL(ping_evictor_stop); |