On Alan's advice, rather than do a wholesale conversion on a single

architecture from page queue lock to a hashed array of page locks
(based on a patch by Jeff Roberson), I've implemented page lock
support in the MI code and have only moved vm_page's hold_count
out from under page queue mutex to page lock. This changes
pmap_extract_and_hold on all pmaps.

Supported by: Bitgravity Inc.

Discussed with: alc, jeffr, and kib

1 files changed, 13 insertions, 6 deletions

diff --git a/sys/vm/device_pager.c b/sys/vm/device_pager.c
index 9002e77..996f740 100644
--- a/sys/vm/device_pager.c
+++ b/sys/vm/device_pager.c
@@ -251,12 +251,16 @@ dev_pager_getpages(object, m, count, reqpage)
 		VM_OBJECT_LOCK(object);
 		dev_pager_updatefake(page, paddr, memattr);
 		if (count > 1) {
-			vm_page_lock_queues();
+
 			for (i = 0; i < count; i++) {
-				if (i != reqpage)
+				if (i != reqpage) {
+					vm_page_lock(m[i]);
+					vm_page_lock_queues();		
 					vm_page_free(m[i]);
+					vm_page_unlock_queues();
+					vm_page_unlock(m[i]);
+				}
 			}
-			vm_page_unlock_queues();
 		}
 	} else {
 		/*
@@ -266,10 +270,13 @@ dev_pager_getpages(object, m, count, reqpage)
 		page = dev_pager_getfake(paddr, memattr);
 		VM_OBJECT_LOCK(object);
 		TAILQ_INSERT_TAIL(&object->un_pager.devp.devp_pglist, page, pageq);
-		vm_page_lock_queues();
-		for (i = 0; i < count; i++)
+		for (i = 0; i < count; i++) {
+			vm_page_lock(m[i]);
+			vm_page_lock_queues();
 			vm_page_free(m[i]);
-		vm_page_unlock_queues();
+			vm_page_unlock_queues();
+			vm_page_unlock(m[i]);
+		}
 		vm_page_insert(page, object, offset);
 		m[reqpage] = page;
 	}