1) Use a more consistent page wait methodology.

2)	Do not unnecessarily force page blocking when paging
	pages out.
3)	Further improve swap pager performance and correctness,
	including fixing the paging in progress deadlock (except
	in severe I/O error conditions.)
4)	Enable vfs_ioopt=1 as a default.
5)	Fix and enable the page prezeroing in SMP mode.

All in all, SMP systems especially should show a significant
improvement in "snappyness."

1 files changed, 7 insertions, 6 deletions

diff --git a/sys/vm/vm_fault.c b/sys/vm/vm_fault.c
index bb352bc..a986aeb 100644
--- a/sys/vm/vm_fault.c
+++ b/sys/vm/vm_fault.c
@@ -66,7 +66,7 @@
  * any improvements or extensions that they make and grant Carnegie the
  * rights to redistribute these changes.
  *
- * $Id: vm_fault.c,v 1.79 1998/02/06 12:14:22 eivind Exp $
+ * $Id: vm_fault.c,v 1.80 1998/02/09 06:11:23 eivind Exp $
  */
 
 /*
@@ -139,6 +139,7 @@ vm_fault(vm_map_t map, vm_offset_t vaddr, vm_prot_t fault_type, int fault_flags)
 	vm_page_t marray[VM_FAULT_READ];
 	int hardfault = 0;
 	int faultcount;
+	int pagewaitbits;
 	struct vnode *vp = NULL;
 	struct proc *p = curproc;	/* XXX */
 
@@ -181,6 +182,7 @@ vm_fault(vm_map_t map, vm_offset_t vaddr, vm_prot_t fault_type, int fault_flags)
 }
 
 
+	pagewaitbits = PG_BUSY;
 RetryFault:;
 	faultcount = 0;
 
@@ -286,7 +288,6 @@ RetryFault:;
 	/*
 	 * See whether this page is resident
 	 */
-
 	while (TRUE) {
 
 		if (object->flags & OBJ_DEAD) {
@@ -301,12 +302,12 @@ RetryFault:;
 			 * If the page is being brought in, wait for it and
 			 * then retry.
 			 */
-			if ((m->flags & PG_BUSY) || m->busy) {
+			if ((m->flags & PG_BUSY) || (m->busy && (m->valid & VM_PAGE_BITS_ALL) != VM_PAGE_BITS_ALL)) {
 				int s;
 
 				UNLOCK_THINGS;
 				s = splvm();
-				if (((m->flags & PG_BUSY) || m->busy)) {
+				if ((m->flags & PG_BUSY) || (m->busy && (m->valid & VM_PAGE_BITS_ALL) != VM_PAGE_BITS_ALL)) {
 					m->flags |= PG_WANTED | PG_REFERENCED;
 					cnt.v_intrans++;
 					tsleep(m, PSWP, "vmpfw", 0);
@@ -331,11 +332,11 @@ RetryFault:;
 			}
 
 			m->flags |= PG_BUSY;
-
 			if (((m->valid & VM_PAGE_BITS_ALL) != VM_PAGE_BITS_ALL) &&
 				m->object != kernel_object && m->object != kmem_object) {
 				goto readrest;
 			}
+
 			break;
 		}
 		if (((object->type != OBJT_DEFAULT) &&
@@ -398,7 +399,7 @@ readrest:
 					if (mt == NULL || (mt->valid != VM_PAGE_BITS_ALL))
 						break;
 					if (mt->busy ||
-						(mt->flags & (PG_BUSY|PG_FICTITIOUS)) ||
+						(mt->flags & (PG_BUSY | PG_FICTITIOUS)) ||
 						mt->hold_count ||
 						mt->wire_count) 
 						continue;