-/* -*- mode: c; c-basic-offset: 8; indent-tabs-mode: nil; -*-
- * vim:expandtab:shiftwidth=8:tabstop=8:
+/*
+ * GPL HEADER START
*
- * lib/lib-eq.c
- * Library level Event queue management routines
+ * 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.
*
- * Copyright (c) 2001-2003 Cluster File Systems, Inc.
+ * 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).
*
- * This file is part of Lustre, http://www.lustre.org
+ * You should have received a copy of the GNU General Public License
+ * version 2 along with this program; If not, see
+ * http://www.gnu.org/licenses/gpl-2.0.html
*
- * Lustre is free software; you can redistribute it and/or
- * modify it under the terms of version 2 of the GNU General Public
- * License as published by the Free Software Foundation.
+ * GPL HEADER END
+ */
+/*
+ * Copyright (c) 2003, 2010, Oracle and/or its affiliates. All rights reserved.
+ * Use is subject to license terms.
+ *
+ * Copyright (c) 2012, 2016, Intel Corporation.
+ */
+/*
+ * This file is part of Lustre, http://www.lustre.org/
+ * Lustre is a trademark of Sun Microsystems, Inc.
*
- * Lustre 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 for more details.
+ * lnet/lnet/lib-eq.c
*
- * You should have received a copy of the GNU General Public License
- * along with Lustre; if not, write to the Free Software
- * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ * Library level Event queue management routines
*/
#define DEBUG_SUBSYSTEM S_LNET
#include <lnet/lib-lnet.h>
+/**
+ * Create an event queue that has room for \a count number of events.
+ *
+ * The event queue is circular and older events will be overwritten by new
+ * ones if they are not removed in time by the user using the functions
+ * LNetEQGet(), LNetEQWait(), or LNetEQPoll(). It is up to the user to
+ * determine the appropriate size of the event queue to prevent this loss
+ * of events. Note that when EQ handler is specified in \a callback, no
+ * event loss can happen, since the handler is run for each event deposited
+ * into the EQ.
+ *
+ * \param count The number of events to be stored in the event queue. It
+ * will be rounded up to the next power of two.
+ * \param callback A handler function that runs when an event is deposited
+ * into the EQ. The constant value LNET_EQ_HANDLER_NONE can be used to
+ * indicate that no event handler is desired.
+ * \param handle On successful return, this location will hold a handle for
+ * the newly created EQ.
+ *
+ * \retval 0 On success.
+ * \retval -EINVAL If an parameter is not valid.
+ * \retval -ENOMEM If memory for the EQ can't be allocated.
+ *
+ * \see lnet_eq_handler_t for the discussion on EQ handler semantics.
+ */
int
-LNetEQAlloc(unsigned int count, lnet_eq_handler_t callback,
- lnet_handle_eq_t *handle)
+LNetEQAlloc(unsigned int count, lnet_eq_handler_t callback,
+ struct lnet_handle_eq *handle)
{
- lnet_eq_t *eq;
-
- LASSERT (the_lnet.ln_init);
- LASSERT (the_lnet.ln_refcount > 0);
-
- /* We need count to be a power of 2 so that when eq_{enq,deq}_seq
- * overflow, they don't skip entries, so the queue has the same
- * apparant capacity at all times */
-
- if (count != LOWEST_BIT_SET(count)) { /* not a power of 2 already */
- do { /* knock off all but the top bit... */
- count &= ~LOWEST_BIT_SET (count);
- } while (count != LOWEST_BIT_SET(count));
-
- count <<= 1; /* ...and round up */
- }
-
- if (count == 0) /* catch bad parameter / overflow on roundup */
- return (-EINVAL);
-
- eq = lnet_eq_alloc();
- if (eq == NULL)
- return (-ENOMEM);
-
- LIBCFS_ALLOC(eq->eq_events, count * sizeof(lnet_event_t));
- if (eq->eq_events == NULL) {
- LNET_LOCK();
- lnet_eq_free (eq);
- LNET_UNLOCK();
-
- return -ENOMEM;
- }
-
- /* NB this resets all event sequence numbers to 0, to be earlier
- * than eq_deq_seq */
- memset(eq->eq_events, 0, count * sizeof(lnet_event_t));
-
- eq->eq_deq_seq = 1;
- eq->eq_enq_seq = 1;
- eq->eq_size = count;
- eq->eq_refcount = 0;
- eq->eq_callback = callback;
-
- LNET_LOCK();
-
- lnet_initialise_handle (&eq->eq_lh, LNET_COOKIE_TYPE_EQ);
- list_add (&eq->eq_list, &the_lnet.ln_active_eqs);
-
- LNET_UNLOCK();
-
- lnet_eq2handle(handle, eq);
- return (0);
+ struct lnet_eq *eq;
+
+ LASSERT(the_lnet.ln_refcount > 0);
+
+ /* We need count to be a power of 2 so that when eq_{enq,deq}_seq
+ * overflow, they don't skip entries, so the queue has the same
+ * apparent capacity at all times */
+
+ if (count)
+ count = roundup_pow_of_two(count);
+
+ if (callback != LNET_EQ_HANDLER_NONE && count != 0) {
+ CWARN("EQ callback is guaranteed to get every event, "
+ "do you still want to set eqcount %d for polling "
+ "event which will have locking overhead? "
+ "Please contact with developer to confirm\n", count);
+ }
+
+ /* count can be 0 if only need callback, we can eliminate
+ * overhead of enqueue event */
+ if (count == 0 && callback == LNET_EQ_HANDLER_NONE)
+ return -EINVAL;
+
+ eq = lnet_eq_alloc();
+ if (eq == NULL)
+ return -ENOMEM;
+
+ if (count != 0) {
+ LIBCFS_ALLOC(eq->eq_events, count * sizeof(*eq->eq_events));
+ if (eq->eq_events == NULL)
+ goto failed;
+ /* NB allocator has set all event sequence numbers to 0,
+ * so all them should be earlier than eq_deq_seq */
+ }
+
+ eq->eq_deq_seq = 1;
+ eq->eq_enq_seq = 1;
+ eq->eq_size = count;
+ eq->eq_callback = callback;
+
+ eq->eq_refs = cfs_percpt_alloc(lnet_cpt_table(),
+ sizeof(*eq->eq_refs[0]));
+ if (eq->eq_refs == NULL)
+ goto failed;
+
+ /* MUST hold both exclusive lnet_res_lock */
+ lnet_res_lock(LNET_LOCK_EX);
+ /* NB: hold lnet_eq_wait_lock for EQ link/unlink, so we can do
+ * both EQ lookup and poll event with only lnet_eq_wait_lock */
+ lnet_eq_wait_lock();
+
+ lnet_res_lh_initialize(&the_lnet.ln_eq_container, &eq->eq_lh);
+ list_add(&eq->eq_list, &the_lnet.ln_eq_container.rec_active);
+
+ lnet_eq_wait_unlock();
+ lnet_res_unlock(LNET_LOCK_EX);
+
+ lnet_eq2handle(handle, eq);
+ return 0;
+
+failed:
+ if (eq->eq_events != NULL)
+ LIBCFS_FREE(eq->eq_events, count * sizeof(*eq->eq_events));
+
+ if (eq->eq_refs != NULL)
+ cfs_percpt_free(eq->eq_refs);
+
+ lnet_eq_free(eq);
+ return -ENOMEM;
}
+EXPORT_SYMBOL(LNetEQAlloc);
+/**
+ * Release the resources associated with an event queue if it's idle;
+ * otherwise do nothing and it's up to the user to try again.
+ *
+ * \param eqh A handle for the event queue to be released.
+ *
+ * \retval 0 If the EQ is not in use and freed.
+ * \retval -ENOENT If \a eqh does not point to a valid EQ.
+ * \retval -EBUSY If the EQ is still in use by some MDs.
+ */
int
-LNetEQFree(lnet_handle_eq_t eqh)
+LNetEQFree(struct lnet_handle_eq eqh)
{
- lnet_eq_t *eq;
- int size;
- lnet_event_t *events;
+ struct lnet_eq *eq;
+ struct lnet_event *events = NULL;
+ int **refs = NULL;
+ int *ref;
+ int rc = 0;
+ int size = 0;
+ int i;
+
+ lnet_res_lock(LNET_LOCK_EX);
+ /* NB: hold lnet_eq_wait_lock for EQ link/unlink, so we can do
+ * both EQ lookup and poll event with only lnet_eq_wait_lock */
+ lnet_eq_wait_lock();
+
+ eq = lnet_handle2eq(&eqh);
+ if (eq == NULL) {
+ rc = -ENOENT;
+ goto out;
+ }
+
+ cfs_percpt_for_each(ref, i, eq->eq_refs) {
+ LASSERT(*ref >= 0);
+ if (*ref == 0)
+ continue;
+
+ CDEBUG(D_NET, "Event equeue (%d: %d) busy on destroy.\n",
+ i, *ref);
+ rc = -EBUSY;
+ goto out;
+ }
+
+ /* stash for free after lock dropped */
+ events = eq->eq_events;
+ size = eq->eq_size;
+ refs = eq->eq_refs;
+
+ lnet_res_lh_invalidate(&eq->eq_lh);
+ list_del(&eq->eq_list);
+ lnet_eq_free(eq);
+ out:
+ lnet_eq_wait_unlock();
+ lnet_res_unlock(LNET_LOCK_EX);
+
+ if (events != NULL)
+ LIBCFS_FREE(events, size * sizeof(*events));
+ if (refs != NULL)
+ cfs_percpt_free(refs);
+
+ return rc;
+}
+EXPORT_SYMBOL(LNetEQFree);
- LASSERT (the_lnet.ln_init);
- LASSERT (the_lnet.ln_refcount > 0);
-
- LNET_LOCK();
+void
+lnet_eq_enqueue_event(struct lnet_eq *eq, struct lnet_event *ev)
+{
+ /* MUST called with resource lock hold but w/o lnet_eq_wait_lock */
+ int index;
- eq = lnet_handle2eq(&eqh);
- if (eq == NULL) {
- LNET_UNLOCK();
- return (-ENOENT);
- }
+ if (eq->eq_size == 0) {
+ LASSERT(eq->eq_callback != LNET_EQ_HANDLER_NONE);
+ eq->eq_callback(ev);
+ return;
+ }
- if (eq->eq_refcount != 0) {
- LNET_UNLOCK();
- return (-EBUSY);
- }
+ lnet_eq_wait_lock();
+ ev->sequence = eq->eq_enq_seq++;
- /* stash for free after lock dropped */
- events = eq->eq_events;
- size = eq->eq_size;
+ LASSERT(eq->eq_size == LOWEST_BIT_SET(eq->eq_size));
+ index = ev->sequence & (eq->eq_size - 1);
- lnet_invalidate_handle (&eq->eq_lh);
- list_del (&eq->eq_list);
- lnet_eq_free (eq);
+ eq->eq_events[index] = *ev;
- LNET_UNLOCK();
+ if (eq->eq_callback != LNET_EQ_HANDLER_NONE)
+ eq->eq_callback(ev);
- LIBCFS_FREE(events, size * sizeof (lnet_event_t));
+ /* Wake anyone waiting in LNetEQPoll() */
+ if (waitqueue_active(&the_lnet.ln_eq_waitq))
+ wake_up_all(&the_lnet.ln_eq_waitq);
+ lnet_eq_wait_unlock();
+}
- return 0;
+static int
+lnet_eq_dequeue_event(struct lnet_eq *eq, struct lnet_event *ev)
+{
+ int new_index = eq->eq_deq_seq & (eq->eq_size - 1);
+ struct lnet_event *new_event = &eq->eq_events[new_index];
+ int rc;
+ ENTRY;
+
+ /* must called with lnet_eq_wait_lock hold */
+ if (LNET_SEQ_GT(eq->eq_deq_seq, new_event->sequence))
+ RETURN(0);
+
+ /* We've got a new event... */
+ *ev = *new_event;
+
+ CDEBUG(D_INFO, "event: %p, sequence: %lu, eq->size: %u\n",
+ new_event, eq->eq_deq_seq, eq->eq_size);
+
+ /* ...but did it overwrite an event we've not seen yet? */
+ if (eq->eq_deq_seq == new_event->sequence) {
+ rc = 1;
+ } else {
+ /* don't complain with CERROR: some EQs are sized small
+ * anyway; if it's important, the caller should complain */
+ CDEBUG(D_NET, "Event Queue Overflow: eq seq %lu ev seq %lu\n",
+ eq->eq_deq_seq, new_event->sequence);
+ rc = -EOVERFLOW;
+ }
+
+ eq->eq_deq_seq = new_event->sequence + 1;
+ RETURN(rc);
}
+/**
+ * A nonblocking function that can be used to get the next event in an EQ.
+ * If an event handler is associated with the EQ, the handler will run before
+ * this function returns successfully. The event is removed from the queue.
+ *
+ * \param eventq A handle for the event queue.
+ * \param event On successful return (1 or -EOVERFLOW), this location will
+ * hold the next event in the EQ.
+ *
+ * \retval 0 No pending event in the EQ.
+ * \retval 1 Indicates success.
+ * \retval -ENOENT If \a eventq does not point to a valid EQ.
+ * \retval -EOVERFLOW Indicates success (i.e., an event is returned) and that
+ * at least one event between this event and the last event obtained from the
+ * EQ has been dropped due to limited space in the EQ.
+ */
int
-lib_get_event (lnet_eq_t *eq, lnet_event_t *ev)
+LNetEQGet(struct lnet_handle_eq eventq, struct lnet_event *event)
{
- int new_index = eq->eq_deq_seq & (eq->eq_size - 1);
- lnet_event_t *new_event = &eq->eq_events[new_index];
- int rc;
- ENTRY;
-
- CDEBUG(D_INFO, "event: %p, sequence: %lu, eq->size: %u\n",
- new_event, eq->eq_deq_seq, eq->eq_size);
-
- if (LNET_SEQ_GT (eq->eq_deq_seq, new_event->sequence)) {
- RETURN(0);
- }
-
- /* We've got a new event... */
- *ev = *new_event;
-
- /* ...but did it overwrite an event we've not seen yet? */
- if (eq->eq_deq_seq == new_event->sequence) {
- rc = 1;
- } else {
- /* don't complain with CERROR: some EQs are sized small
- * anyway; if it's important, the caller should complain */
- CDEBUG(D_NET, "Event Queue Overflow: eq seq %lu ev seq %lu\n",
- eq->eq_deq_seq, new_event->sequence);
- rc = -EOVERFLOW;
- }
-
- eq->eq_deq_seq = new_event->sequence + 1;
- RETURN(rc);
-}
+ int which;
+ return LNetEQPoll(&eventq, 1, 0,
+ event, &which);
+}
+EXPORT_SYMBOL(LNetEQGet);
+/**
+ * Block the calling process until there is an event in the EQ.
+ * If an event handler is associated with the EQ, the handler will run before
+ * this function returns successfully. This function returns the next event
+ * in the EQ and removes it from the EQ.
+ *
+ * \param eventq A handle for the event queue.
+ * \param event On successful return (1 or -EOVERFLOW), this location will
+ * hold the next event in the EQ.
+ *
+ * \retval 1 Indicates success.
+ * \retval -ENOENT If \a eventq does not point to a valid EQ.
+ * \retval -EOVERFLOW Indicates success (i.e., an event is returned) and that
+ * at least one event between this event and the last event obtained from the
+ * EQ has been dropped due to limited space in the EQ.
+ */
int
-LNetEQGet (lnet_handle_eq_t eventq, lnet_event_t *event)
+LNetEQWait(struct lnet_handle_eq eventq, struct lnet_event *event)
{
- int which;
+ int which;
- return LNetEQPoll(&eventq, 1, 0,
- event, &which);
+ return LNetEQPoll(&eventq, 1, MAX_SCHEDULE_TIMEOUT,
+ event, &which);
}
+EXPORT_SYMBOL(LNetEQWait);
-int
-LNetEQWait (lnet_handle_eq_t eventq, lnet_event_t *event)
+static int
+lnet_eq_wait_locked(signed long *timeout)
+__must_hold(&the_lnet.ln_eq_wait_lock)
{
- int which;
+ signed long tms = *timeout;
+ wait_queue_entry_t wl;
+ int wait;
+
+ if (tms == 0)
+ return -ENXIO; /* don't want to wait and no new event */
- return LNetEQPoll(&eventq, 1, LNET_TIME_FOREVER,
- event, &which);
+ init_waitqueue_entry(&wl, current);
+ add_wait_queue(&the_lnet.ln_eq_waitq, &wl);
+
+ lnet_eq_wait_unlock();
+
+ tms = schedule_timeout_interruptible(tms);
+ wait = tms != 0; /* might need to call here again */
+ *timeout = tms;
+
+ lnet_eq_wait_lock();
+ remove_wait_queue(&the_lnet.ln_eq_waitq, &wl);
+
+ return wait;
}
+/**
+ * Block the calling process until there's an event from a set of EQs or
+ * timeout happens.
+ *
+ * If an event handler is associated with the EQ, the handler will run before
+ * this function returns successfully, in which case the corresponding event
+ * is consumed.
+ *
+ * LNetEQPoll() provides a timeout to allow applications to poll, block for a
+ * fixed period, or block indefinitely.
+ *
+ * \param eventqs,neq An array of EQ handles, and size of the array.
+ * \param timeout Time in jiffies to wait for an event to occur on
+ * one of the EQs. The constant MAX_SCHEDULE_TIMEOUT can be used to indicate an
+ * infinite timeout.
+ * \param event,which On successful return (1 or -EOVERFLOW), \a event will
+ * hold the next event in the EQs, and \a which will contain the index of the
+ * EQ from which the event was taken.
+ *
+ * \retval 0 No pending event in the EQs after timeout.
+ * \retval 1 Indicates success.
+ * \retval -EOVERFLOW Indicates success (i.e., an event is returned) and that
+ * at least one event between this event and the last event obtained from the
+ * EQ indicated by \a which has been dropped due to limited space in the EQ.
+ * \retval -ENOENT If there's an invalid handle in \a eventqs.
+ */
int
-LNetEQPoll (lnet_handle_eq_t *eventqs, int neq, int timeout_ms,
- lnet_event_t *event, int *which)
+LNetEQPoll(struct lnet_handle_eq *eventqs, int neq, signed long timeout,
+ struct lnet_event *event, int *which)
{
- int i;
- int rc;
-#ifdef __KERNEL__
- cfs_waitlink_t wl;
- cfs_time_t now;
-#else
- struct timeval then;
- struct timeval now;
-# ifdef HAVE_LIBPTHREAD
- struct timespec ts;
-# endif
- lnet_ni_t *eqwaitni = the_lnet.ln_eqwaitni;
-#endif
- ENTRY;
-
- LASSERT (the_lnet.ln_init);
- LASSERT (the_lnet.ln_refcount > 0);
-
- if (neq < 1)
- RETURN(-ENOENT);
-
- LNET_LOCK();
-
- for (;;) {
- for (i = 0; i < neq; i++) {
- lnet_eq_t *eq = lnet_handle2eq(&eventqs[i]);
-
- if (eq == NULL) {
- LNET_UNLOCK();
- RETURN(-ENOENT);
- }
-
- rc = lib_get_event (eq, event);
- if (rc != 0) {
- LNET_UNLOCK();
- *which = i;
- RETURN(rc);
- }
- }
-
-#ifdef __KERNEL__
- if (timeout_ms == 0) {
- LNET_UNLOCK ();
- RETURN (0);
- }
-
- cfs_waitlink_init(&wl);
- set_current_state(TASK_INTERRUPTIBLE);
- cfs_waitq_add(&the_lnet.ln_waitq, &wl);
-
- LNET_UNLOCK();
-
- if (timeout_ms < 0) {
- cfs_waitq_wait (&wl, CFS_TASK_INTERRUPTIBLE);
- } else {
- struct timeval tv;
-
- now = cfs_time_current();
- cfs_waitq_timedwait(&wl, CFS_TASK_INTERRUPTIBLE,
- cfs_time_seconds(timeout_ms)/1000);
- cfs_duration_usec(cfs_time_sub(cfs_time_current(), now),
- &tv);
- timeout_ms -= tv.tv_sec * 1000 + tv.tv_usec / 1000;
- if (timeout_ms < 0)
- timeout_ms = 0;
- }
-
- LNET_LOCK();
- cfs_waitq_del(&the_lnet.ln_waitq, &wl);
-#else
- if (eqwaitni != NULL) {
- /* I have a single NI that I have to call into, to get
- * events queued, or to block. */
- lnet_ni_addref_locked(eqwaitni);
- LNET_UNLOCK();
-
- if (timeout_ms <= 0) {
- (eqwaitni->ni_lnd->lnd_wait)(eqwaitni, timeout_ms);
- } else {
- gettimeofday(&then, NULL);
-
- (eqwaitni->ni_lnd->lnd_wait)(eqwaitni, timeout_ms);
-
- gettimeofday(&now, NULL);
- timeout_ms -= (now.tv_sec - then.tv_sec) * 1000 +
- (now.tv_usec - then.tv_usec) / 1000;
- if (timeout_ms < 0)
- timeout_ms = 0;
- }
-
- LNET_LOCK();
- lnet_ni_decref_locked(eqwaitni);
-
- /* don't call into eqwaitni again if timeout has
- * expired */
- if (timeout_ms == 0)
- eqwaitni = NULL;
-
- continue; /* go back and check for events */
- }
-
- if (timeout_ms == 0) {
- LNET_UNLOCK();
- RETURN (0);
- }
-
-# ifndef HAVE_LIBPTHREAD
- /* If I'm single-threaded, LNET fails at startup if it can't
- * set the_lnet.ln_eqwaitni correctly. */
- LBUG();
-# else
- if (timeout_ms < 0) {
- pthread_cond_wait(&the_lnet.ln_cond,
- &the_lnet.ln_lock);
- } else {
- gettimeofday(&then, NULL);
-
- ts.tv_sec = then.tv_sec + timeout_ms/1000;
- ts.tv_nsec = then.tv_usec * 1000 +
- (timeout_ms%1000) * 1000000;
- if (ts.tv_nsec >= 1000000000) {
- ts.tv_sec++;
- ts.tv_nsec -= 1000000000;
- }
-
- pthread_cond_timedwait(&the_lnet.ln_cond,
- &the_lnet.ln_lock, &ts);
-
- gettimeofday(&now, NULL);
- timeout_ms -= (now.tv_sec - then.tv_sec) * 1000 +
- (now.tv_usec - then.tv_usec) / 1000;
-
- if (timeout_ms < 0)
- timeout_ms = 0;
- }
-# endif
-#endif
- }
+ int wait = 1;
+ int rc;
+ int i;
+ ENTRY;
+
+ LASSERT(the_lnet.ln_refcount > 0);
+
+ if (neq < 1)
+ RETURN(-ENOENT);
+
+ lnet_eq_wait_lock();
+
+ for (;;) {
+ for (i = 0; i < neq; i++) {
+ struct lnet_eq *eq = lnet_handle2eq(&eventqs[i]);
+
+ if (eq == NULL) {
+ lnet_eq_wait_unlock();
+ RETURN(-ENOENT);
+ }
+
+ rc = lnet_eq_dequeue_event(eq, event);
+ if (rc != 0) {
+ lnet_eq_wait_unlock();
+ *which = i;
+ RETURN(rc);
+ }
+ }
+
+ if (wait == 0)
+ break;
+
+ /*
+ * return value of lnet_eq_wait_locked:
+ * -1 : did nothing and it's sure no new event
+ * 1 : sleep inside and wait until new event
+ * 0 : don't want to wait anymore, but might have new event
+ * so need to call dequeue again
+ */
+ wait = lnet_eq_wait_locked(&timeout);
+ if (wait < 0) /* no new event */
+ break;
+ }
+
+ lnet_eq_wait_unlock();
+ RETURN(0);
}
git://git.whamcloud.com / fs / lustre-release.git / blobdiff