Fix two long-standing, but likely harmless, errors in the use of

vm_pageout_deficit:
1. Update vm_pageout_deficit before VM_WAIT.  There is no sense in
   delaying the update; the sooner the pageout daemon receives this
   information the better.  Reviewed by: tegge
2. Update vm_pageout_deficit according to the number of pages still
   needed to complete the allocation, not the original size of the
   allocation.  Submitted by: tegge

(These errors have existed since the introduction of vm_pageout_deficit
in revision 1.144.)

1 files changed, 2 insertions, 2 deletions

diff --git a/sys/kern/vfs_bio.c b/sys/kern/vfs_bio.c
index 01f1795..1f1914c 100644
--- a/sys/kern/vfs_bio.c
+++ b/sys/kern/vfs_bio.c
@@ -2756,9 +2756,9 @@ allocbuf(struct buf *bp, int size)
 					m = vm_page_alloc(obj, pi,
 					    VM_ALLOC_SYSTEM | VM_ALLOC_WIRED);
 					if (m == NULL) {
-						VM_WAIT;
 						atomic_add_int(&vm_pageout_deficit,
 						    desiredpages - bp->b_npages);
+						VM_WAIT;
 					} else {
 						vm_page_lock_queues();
 						vm_page_wakeup(m);
@@ -3490,7 +3490,7 @@ tryagain:
 		vm_object_unlock(kernel_object);
 		if (!p) {
 			atomic_add_int(&vm_pageout_deficit,
-			    (to - from) >> PAGE_SHIFT);
+			    (to - pg) >> PAGE_SHIFT);
 			VM_WAIT;
 			goto tryagain;
 		}