/*
* Copyright (c) 2003, 2010, Oracle and/or its affiliates. All rights reserved.
* Use is subject to license terms.
+ *
+ * Copyright (c) 2012, Intel Corporation.
*/
/*
* This file is part of Lustre, http://www.lustre.org/
* overflow, they don't skip entries, so the queue has the same
* apparent 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 */
- }
+ count = cfs_power2_roundup(count);
- if (count == 0) /* catch bad parameter / overflow on roundup */
- return (-EINVAL);
+ 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);
+ }
- eq = lnet_eq_alloc();
- if (eq == NULL)
- return (-ENOMEM);
+ /* 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;
- LIBCFS_ALLOC(eq->eq_events, count * sizeof(lnet_event_t));
- if (eq->eq_events == NULL) {
- lnet_eq_free(eq);
-
- return -ENOMEM;
- }
+ eq = lnet_eq_alloc();
+ if (eq == NULL)
+ 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));
+ if (count != 0) {
+ LIBCFS_ALLOC(eq->eq_events, count * sizeof(lnet_event_t));
+ 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_refcount = 0;
eq->eq_callback = callback;
- LNET_LOCK();
+ eq->eq_refs = cfs_percpt_alloc(lnet_cpt_table(),
+ sizeof(*eq->eq_refs[0]));
+ if (eq->eq_refs == NULL)
+ goto failed;
- lnet_initialise_handle (&eq->eq_lh, LNET_COOKIE_TYPE_EQ);
- cfs_list_add (&eq->eq_list, &the_lnet.ln_active_eqs);
+ /* 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_UNLOCK();
+ 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_eq2handle(handle, eq);
- return (0);
+ 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(lnet_event_t));
+
+ 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;
int
LNetEQFree(lnet_handle_eq_t eqh)
{
- lnet_eq_t *eq;
- int size;
- lnet_event_t *events;
+ struct lnet_eq *eq;
+ lnet_event_t *events = NULL;
+ int **refs = NULL;
+ int *ref;
+ int rc = 0;
+ int size = 0;
+ int i;
+
+ LASSERT(the_lnet.ln_init);
+ LASSERT(the_lnet.ln_refcount > 0);
+
+ 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_locked(eq);
+ out:
+ lnet_eq_wait_unlock();
+ lnet_res_unlock(LNET_LOCK_EX);
- LASSERT (the_lnet.ln_init);
- LASSERT (the_lnet.ln_refcount > 0);
+ if (events != NULL)
+ LIBCFS_FREE(events, size * sizeof(lnet_event_t));
+ if (refs != NULL)
+ cfs_percpt_free(refs);
- LNET_LOCK();
+ return rc;
+}
+EXPORT_SYMBOL(LNetEQFree);
- eq = lnet_handle2eq(&eqh);
- if (eq == NULL) {
- LNET_UNLOCK();
- return (-ENOENT);
- }
+void
+lnet_eq_enqueue_event(lnet_eq_t *eq, lnet_event_t *ev)
+{
+ /* MUST called with resource lock hold but w/o lnet_eq_wait_lock */
+ int index;
- if (eq->eq_refcount != 0) {
- CDEBUG(D_NET, "Event queue (%d) busy on destroy.\n",
- eq->eq_refcount);
- LNET_UNLOCK();
- return (-EBUSY);
- }
+ if (eq->eq_size == 0) {
+ LASSERT(eq->eq_callback != LNET_EQ_HANDLER_NONE);
+ eq->eq_callback(ev);
+ return;
+ }
- /* stash for free after lock dropped */
- events = eq->eq_events;
- size = eq->eq_size;
+ lnet_eq_wait_lock();
+ ev->sequence = eq->eq_enq_seq++;
- lnet_invalidate_handle (&eq->eq_lh);
- cfs_list_del (&eq->eq_list);
- lnet_eq_free_locked(eq);
+ LASSERT(eq->eq_size == LOWEST_BIT_SET(eq->eq_size));
+ index = ev->sequence & (eq->eq_size - 1);
- LNET_UNLOCK();
+ eq->eq_events[index] = *ev;
- LIBCFS_FREE(events, size * sizeof (lnet_event_t));
+ if (eq->eq_callback != LNET_EQ_HANDLER_NONE)
+ eq->eq_callback(ev);
- return 0;
+#ifdef __KERNEL__
+ /* Wake anyone waiting in LNetEQPoll() */
+ if (waitqueue_active(&the_lnet.ln_eq_waitq))
+ wake_up_all(&the_lnet.ln_eq_waitq);
+#else
+# ifndef HAVE_LIBPTHREAD
+ /* LNetEQPoll() calls into _the_ LND to wait for action */
+# else
+ /* Wake anyone waiting in LNetEQPoll() */
+ pthread_cond_broadcast(&the_lnet.ln_eq_cond);
+# endif
+#endif
+ lnet_eq_wait_unlock();
}
int
-lib_get_event (lnet_eq_t *eq, lnet_event_t *ev)
+lnet_eq_dequeue_event(lnet_eq_t *eq, lnet_event_t *ev)
{
- int new_index = eq->eq_deq_seq & (eq->eq_size - 1);
- lnet_event_t *new_event = &eq->eq_events[new_index];
- int rc;
- ENTRY;
+ 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);
+ /* must called with lnet_eq_wait_lock hold */
+ if (LNET_SEQ_GT(eq->eq_deq_seq, new_event->sequence))
+ RETURN(0);
- if (LNET_SEQ_GT (eq->eq_deq_seq, new_event->sequence)) {
- RETURN(0);
- }
+ /* We've got a new event... */
+ *ev = *new_event;
- /* 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) {
return LNetEQPoll(&eventq, 1, 0,
event, &which);
}
+EXPORT_SYMBOL(LNetEQGet);
/**
* Block the calling process until there is an event in the EQ.
return LNetEQPoll(&eventq, 1, LNET_TIME_FOREVER,
event, &which);
}
+EXPORT_SYMBOL(LNetEQWait);
+
+#ifdef __KERNEL__
+
+static int
+lnet_eq_wait_locked(int *timeout_ms)
+__must_hold(&the_lnet.ln_eq_wait_lock)
+{
+ int tms = *timeout_ms;
+ int wait;
+ wait_queue_t wl;
+ cfs_time_t now;
+
+ if (tms == 0)
+ return -1; /* don't want to wait and no new event */
+
+ init_waitqueue_entry_current(&wl);
+ set_current_state(TASK_INTERRUPTIBLE);
+ add_wait_queue(&the_lnet.ln_eq_waitq, &wl);
+
+ lnet_eq_wait_unlock();
+
+ if (tms < 0) {
+ waitq_wait(&wl, TASK_INTERRUPTIBLE);
+
+ } else {
+ struct timeval tv;
+
+ now = cfs_time_current();
+ waitq_timedwait(&wl, TASK_INTERRUPTIBLE,
+ cfs_time_seconds(tms) / 1000);
+ cfs_duration_usec(cfs_time_sub(cfs_time_current(), now), &tv);
+ tms -= (int)(tv.tv_sec * 1000 + tv.tv_usec / 1000);
+ if (tms < 0) /* no more wait but may have new event */
+ tms = 0;
+ }
+
+ wait = tms != 0; /* might need to call here again */
+ *timeout_ms = tms;
+
+ lnet_eq_wait_lock();
+ remove_wait_queue(&the_lnet.ln_eq_waitq, &wl);
+
+ return wait;
+}
+
+#else /* !__KERNEL__ */
+
+# ifdef HAVE_LIBPTHREAD
+static void
+lnet_eq_cond_wait(struct timespec *ts)
+{
+ if (ts == NULL) {
+ pthread_cond_wait(&the_lnet.ln_eq_cond,
+ &the_lnet.ln_eq_wait_lock);
+ } else {
+ pthread_cond_timedwait(&the_lnet.ln_eq_cond,
+ &the_lnet.ln_eq_wait_lock, ts);
+ }
+}
+# endif
+
+static int
+lnet_eq_wait_locked(int *timeout_ms)
+{
+ lnet_ni_t *eq_waitni = NULL;
+ int tms = *timeout_ms;
+ int wait;
+ struct timeval then;
+ struct timeval now;
+
+ if (the_lnet.ln_eq_waitni != NULL) {
+ /* I have a single NI that I have to call into, to get
+ * events queued, or to block. */
+ lnet_eq_wait_unlock();
+
+ lnet_net_lock(0);
+ eq_waitni = the_lnet.ln_eq_waitni;
+ if (unlikely(eq_waitni == NULL)) {
+ lnet_net_unlock(0);
+
+ lnet_eq_wait_lock();
+ return -1;
+ }
+
+ lnet_ni_addref_locked(eq_waitni, 0);
+ lnet_net_unlock(0);
+
+ if (tms <= 0) { /* even for tms == 0 */
+ (eq_waitni->ni_lnd->lnd_wait)(eq_waitni, tms);
+
+ } else {
+ gettimeofday(&then, NULL);
+
+ (eq_waitni->ni_lnd->lnd_wait)(eq_waitni, tms);
+
+ gettimeofday(&now, NULL);
+ tms -= (now.tv_sec - then.tv_sec) * 1000 +
+ (now.tv_usec - then.tv_usec) / 1000;
+ if (tms < 0)
+ tms = 0;
+ }
+
+ lnet_ni_decref(eq_waitni);
+ lnet_eq_wait_lock();
+ } else { /* w/o eq_waitni */
+# ifndef HAVE_LIBPTHREAD
+ /* If I'm single-threaded, LNET fails at startup if it can't
+ * set the_lnet.ln_eqwaitni correctly. */
+ LBUG();
+# else /* HAVE_LIBPTHREAD */
+ struct timespec ts;
+
+ if (tms == 0) /* don't want to wait and new event */
+ return -1;
+
+ if (tms < 0) {
+ lnet_eq_cond_wait(NULL);
+
+ } else {
+
+ gettimeofday(&then, NULL);
+
+ ts.tv_sec = then.tv_sec + tms / 1000;
+ ts.tv_nsec = then.tv_usec * 1000 +
+ (tms % 1000) * 1000000;
+ if (ts.tv_nsec >= 1000000000) {
+ ts.tv_sec++;
+ ts.tv_nsec -= 1000000000;
+ }
+
+ lnet_eq_cond_wait(&ts);
+
+ gettimeofday(&now, NULL);
+ tms -= (now.tv_sec - then.tv_sec) * 1000 +
+ (now.tv_usec - then.tv_usec) / 1000;
+ if (tms < 0)
+ tms = 0;
+ }
+# endif /* HAVE_LIBPTHREAD */
+ }
+
+ wait = tms != 0;
+ *timeout_ms = tms;
+
+ return wait;
+}
+
+#endif /* __KERNEL__ */
+
/**
* Block the calling process until there's an event from a set of EQs or
* \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(lnet_handle_eq_t *eventqs, int neq, int timeout_ms,
+ lnet_event_t *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
+ int wait = 1;
+ int rc;
+ int i;
ENTRY;
LASSERT (the_lnet.ln_init);
if (neq < 1)
RETURN(-ENOENT);
- LNET_LOCK();
+ lnet_eq_wait_lock();
- for (;;) {
+ for (;;) {
#ifndef __KERNEL__
- LNET_UNLOCK();
+ lnet_eq_wait_unlock();
- /* Recursion breaker */
- if (the_lnet.ln_rc_state == LNET_RC_STATE_RUNNING &&
- !LNetHandleIsEqual(eventqs[0], the_lnet.ln_rc_eqh))
- lnet_router_checker();
+ /* Recursion breaker */
+ if (the_lnet.ln_rc_state == LNET_RC_STATE_RUNNING &&
+ !LNetHandleIsEqual(eventqs[0], the_lnet.ln_rc_eqh))
+ lnet_router_checker();
- LNET_LOCK();
+ lnet_eq_wait_lock();
#endif
- 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);
- cfs_set_current_state(CFS_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 -= (int)(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
- }
+ for (i = 0; i < neq; i++) {
+ lnet_eq_t *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_ms);
+ if (wait < 0) /* no new event */
+ break;
+ }
+
+ lnet_eq_wait_unlock();
+ RETURN(0);
}