svn commit: r207798 - head/sys/vm

[Alan Cox]

Author: alc
Date: Sat May  8 21:35:51 2010
New Revision: 207798
URL: http://svn.freebsd.org/changeset/base/207798

Log:
  Minimize the scope of the page queues lock in vm_fault().

Modified:
  head/sys/vm/vm_fault.c
  head/sys/vm/vm_page.c

Modified: head/sys/vm/vm_fault.c
==============================================================================
--- head/sys/vm/vm_fault.c	Sat May  8 21:18:22 2010	(r207797)
+++ head/sys/vm/vm_fault.c	Sat May  8 21:35:51 2010	(r207798)
@@ -306,7 +306,6 @@ RetryFault:;
 			 * which is not what we want.
 			 */
 			vm_page_lock(fs.m);
-			vm_page_lock_queues();
 			if ((fs.m->cow) && 
 			    (fault_type & VM_PROT_WRITE) &&
 			    (fs.object == fs.first_object)) {
@@ -337,6 +336,7 @@ RetryFault:;
 				 * sleeping so that the page daemon is less
 				 * likely to reclaim it. 
 				 */
+				vm_page_lock_queues();
 				vm_page_flag_set(fs.m, PG_REFERENCED);
 				vm_page_unlock_queues();
 				vm_page_unlock(fs.m);
@@ -363,6 +363,7 @@ RetryFault:;
 				vm_object_deallocate(fs.first_object);
 				goto RetryFault;
 			}
+			vm_page_lock_queues();
 			vm_pageq_remove(fs.m);
 			vm_page_unlock_queues();
 			vm_page_unlock(fs.m);

Modified: head/sys/vm/vm_page.c
==============================================================================
--- head/sys/vm/vm_page.c	Sat May  8 21:18:22 2010	(r207797)
+++ head/sys/vm/vm_page.c	Sat May  8 21:35:51 2010	(r207798)
@@ -2233,6 +2233,7 @@ vm_page_cowfault(vm_page_t m)
 	vm_object_t object;
 	vm_pindex_t pindex;
 
+	mtx_assert(&vm_page_queue_mtx, MA_NOTOWNED);
 	vm_page_lock_assert(m, MA_OWNED);
 	object = m->object;
 	VM_OBJECT_LOCK_ASSERT(object, MA_OWNED);
@@ -2243,7 +2244,6 @@ vm_page_cowfault(vm_page_t m)
 
  retry_alloc:
 	pmap_remove_all(m);
-	vm_page_unlock_queues();
 	vm_page_remove(m);
 	mnew = vm_page_alloc(object, pindex, VM_ALLOC_NORMAL | VM_ALLOC_NOBUSY);
 	if (mnew == NULL) {
@@ -2254,7 +2254,6 @@ vm_page_cowfault(vm_page_t m)
 		VM_OBJECT_LOCK(object);
 		if (m == vm_page_lookup(object, pindex)) {
 			vm_page_lock(m);
-			vm_page_lock_queues();
 			goto retry_alloc;
 		} else {
 			/*
@@ -2272,9 +2271,7 @@ vm_page_cowfault(vm_page_t m)
 		 */
 		vm_page_unlock(m);
 		vm_page_lock(mnew);
-		vm_page_lock_queues();
 		vm_page_free(mnew);
-		vm_page_unlock_queues();
 		vm_page_unlock(mnew);
 		vm_page_insert(m, object, pindex);
 	} else { /* clear COW & copy page */