Modify vm_phys_unfree_page() so that it no longer requires the given

page to be in the free lists.  Instead, it now returns TRUE if it
removed the page from the free lists and FALSE if the page was not
in the free lists.

This change is required to support superpage reservations.  Specifically,
once reservations are introduced, a cached page can either be in the
free lists or a reservation.

1 files changed, 5 insertions, 2 deletions

diff --git a/sys/vm/vm_page.c b/sys/vm/vm_page.c
index 4e68410..622f5fd 100644
--- a/sys/vm/vm_page.c
+++ b/sys/vm/vm_page.c
@@ -1026,8 +1026,11 @@ vm_page_alloc(vm_object_t object, vm_pindex_t pindex, int req)
 				mtx_unlock(&vm_page_queue_free_mtx);
 				return (NULL);
 			}
-			vm_phys_unfree_page(m);
-			vm_phys_set_pool(VM_FREEPOOL_DEFAULT, m, 0);
+			if (vm_phys_unfree_page(m))
+				vm_phys_set_pool(VM_FREEPOOL_DEFAULT, m, 0);
+			else
+				panic("vm_page_alloc: cache page %p is missing"
+				    " from the free queue", m);
 		} else if ((req & VM_ALLOC_IFCACHED) != 0) {
 			mtx_unlock(&vm_page_queue_free_mtx);
 			return (NULL);