diff options
Diffstat (limited to 'module/zfs/rrwlock.c')
| -rw-r--r-- | module/zfs/rrwlock.c | 39 |
1 files changed, 27 insertions, 12 deletions
diff --git a/module/zfs/rrwlock.c b/module/zfs/rrwlock.c index 710685dbc..4cef53f95 100644 --- a/module/zfs/rrwlock.c +++ b/module/zfs/rrwlock.c @@ -19,12 +19,10 @@ * CDDL HEADER END */ /* - * Copyright 2007 Sun Microsystems, Inc. All rights reserved. + * Copyright 2009 Sun Microsystems, Inc. All rights reserved. * Use is subject to license terms. */ -#pragma ident "%Z%%M% %I% %E% SMI" - #include <sys/refcount.h> #include <sys/rrwlock.h> @@ -118,7 +116,7 @@ rrn_find_and_remove(rrwlock_t *rrl) rrw_node_t *prev = NULL; if (refcount_count(&rrl->rr_linked_rcount) == 0) - return (NULL); + return (B_FALSE); for (rn = tsd_get(rrw_tsd_key); rn != NULL; rn = rn->rn_next) { if (rn->rn_rrl == rrl) { @@ -159,6 +157,14 @@ static void rrw_enter_read(rrwlock_t *rrl, void *tag) { mutex_enter(&rrl->rr_lock); +#if !defined(DEBUG) && defined(_KERNEL) + if (!rrl->rr_writer && !rrl->rr_writer_wanted) { + rrl->rr_anon_rcount.rc_count++; + mutex_exit(&rrl->rr_lock); + return; + } + DTRACE_PROBE(zfs__rrwfastpath__rdmiss); +#endif ASSERT(rrl->rr_writer != curthread); ASSERT(refcount_count(&rrl->rr_anon_rcount) >= 0); @@ -208,19 +214,28 @@ void rrw_exit(rrwlock_t *rrl, void *tag) { mutex_enter(&rrl->rr_lock); +#if !defined(DEBUG) && defined(_KERNEL) + if (!rrl->rr_writer && rrl->rr_linked_rcount.rc_count == 0) { + rrl->rr_anon_rcount.rc_count--; + if (rrl->rr_anon_rcount.rc_count == 0) + cv_broadcast(&rrl->rr_cv); + mutex_exit(&rrl->rr_lock); + return; + } + DTRACE_PROBE(zfs__rrwfastpath__exitmiss); +#endif ASSERT(!refcount_is_zero(&rrl->rr_anon_rcount) || !refcount_is_zero(&rrl->rr_linked_rcount) || rrl->rr_writer != NULL); if (rrl->rr_writer == NULL) { - if (rrn_find_and_remove(rrl)) { - if (refcount_remove(&rrl->rr_linked_rcount, tag) == 0) - cv_broadcast(&rrl->rr_cv); - - } else { - if (refcount_remove(&rrl->rr_anon_rcount, tag) == 0) - cv_broadcast(&rrl->rr_cv); - } + int64_t count; + if (rrn_find_and_remove(rrl)) + count = refcount_remove(&rrl->rr_linked_rcount, tag); + else + count = refcount_remove(&rrl->rr_anon_rcount, tag); + if (count == 0) + cv_broadcast(&rrl->rr_cv); } else { ASSERT(rrl->rr_writer == curthread); ASSERT(refcount_is_zero(&rrl->rr_anon_rcount) && |