Add -p switch to "zpool get"

[zfs.git] / module / zfs / rrwlock.c

diff --git a/module/zfs/rrwlock.c b/module/zfs/rrwlock.c
index 710685d..4cef53f 100644 (file)
--- 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) &&