Add a helper function vm_pageout_page_lock(), similar to tegge'

vm_pageout_fallback_object_lock(), to obtain the page lock
while having page queue lock locked, and still maintain the
page position in a queue.

Use the helper to lock the page in the pageout daemon and contig launder
iterators instead of skipping the page if its lock is contested.
Skipping locked pages easily causes pagedaemon or launder to not make a
progress with page cleaning.

Proposed and reviewed by:	alc

1 files changed, 4 insertions, 2 deletions

diff --git a/sys/vm/vm_contig.c b/sys/vm/vm_contig.c
index c1c8618..1286c17 100644
--- a/sys/vm/vm_contig.c
+++ b/sys/vm/vm_contig.c
@@ -168,8 +168,10 @@ vm_contig_launder(int queue)
 		if ((m->flags & PG_MARKER) != 0)
 			continue;
 
-		if (!vm_page_trylock(m))
-			continue;
+		if (!vm_pageout_page_lock(m, &next)) {
+			vm_page_unlock(m);
+			return (FALSE);
+		}
 		KASSERT(VM_PAGE_INQUEUE2(m, queue),
 		    ("vm_contig_launder: page %p's queue is not %d", m, queue));
 		error = vm_contig_launder_page(m, &next);