zfs arc_reclaim_thread: no need to call arc_reclaim_needed when

resetting needfree

needfree is checked at the very start of arc_reclaim_needed.
This change makes code easier to follow and maintain in face of
potential changed in arc_reclaim_needed.

Also, put the whole sub-block under _KERNEL because needfree can be set
only in kernel code.

To do: rename needfree to something else to aovid confusion with
OpenSolaris global variable of the same name which is used in the same
code, but has different meaning (page deficit).

Note: I have an impression that locking around accesses to this variable
as well as mutual notifications between arc_reclaim_thread and
arc_lowmem are not proper.

MFC after:	1 week

1 files changed, 3 insertions, 3 deletions

diff --git a/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/arc.c b/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/arc.c
index 1666e41..32c079a 100644
--- a/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/arc.c
+++ b/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/arc.c
@@ -2317,12 +2317,12 @@ arc_reclaim_thread(void *dummy __unused)
 		if (arc_eviction_list != NULL)
 			arc_do_user_evicts();
 
-		if (arc_reclaim_needed()) {
-			needfree = 0;
 #ifdef _KERNEL
+		if (needfree) {
+			needfree = 0;
 			wakeup(&needfree);
-#endif
 		}
+#endif
 
 		/* block until needed, or one second, whichever is shorter */
 		CALLB_CPR_SAFE_BEGIN(&cpr);