Fix the problem with pmap_copy that breaks X in small memory machines. Also

close some windows that are opened up by page table allocations.  The
prefaulting code no longer uses hold counts, but now uses the busy
flag for synchronization.

1 files changed, 23 insertions, 13 deletions

diff --git a/sys/amd64/amd64/pmap.c b/sys/amd64/amd64/pmap.c
index da77829..373396b 100644
--- a/sys/amd64/amd64/pmap.c
+++ b/sys/amd64/amd64/pmap.c
@@ -39,7 +39,7 @@
  * SUCH DAMAGE.
  *
  *	from:	@(#)pmap.c	7.7 (Berkeley)	5/12/91
- *	$Id: pmap.c,v 1.95 1996/05/29 05:09:07 dyson Exp $
+ *	$Id: pmap.c,v 1.96 1996/05/31 00:37:48 dyson Exp $
  */
 
 /*
@@ -677,8 +677,8 @@ pmap_release_free_page(pmap, p)
 	}
 
 	if (p->flags & PG_MAPPED) {
-		pmap_remove_pte_mapping(VM_PAGE_TO_PHYS(p));
 		p->flags &= ~PG_MAPPED;
+		pmap_remove_pte_mapping(VM_PAGE_TO_PHYS(p));
 	}
 
 #if defined(PMAP_DIAGNOSTIC)
@@ -983,6 +983,7 @@ pmap_remove_pte(pmap, ptq, va)
 {
 	unsigned oldpte;
 	pv_entry_t *ppv;
+	int rtval;
 
 	oldpte = *ptq;
 	*ptq = 0;
@@ -1001,7 +1002,13 @@ pmap_remove_pte(pmap, ptq, va)
 			}
 		}
 		ppv = pa_to_pvh(oldpte);
-		return pmap_remove_entry(pmap, ppv, va);
+		rtval = pmap_remove_entry(pmap, ppv, va);
+#if defined(notyet)
+		if (*ppv == NULL) {
+			PHYS_TO_VM_PAGE(oldpte)->flags &= ~PG_MAPPED;
+		}
+#endif
+		return rtval;
 	} else {
 		return pmap_unuse_pt(pmap, va, NULL);
 	}
@@ -1733,12 +1740,12 @@ pmap_object_init_pt(pmap, addr, object, pindex, size, limit)
 			    (p->flags & (PG_BUSY | PG_FICTITIOUS)) == 0) {
 				if (p->queue == PQ_CACHE)
 					vm_page_deactivate(p);
-				vm_page_hold(p);
-				p->flags |= PG_MAPPED;
+				p->flags |= PG_BUSY;
 				pmap_enter_quick(pmap, 
 					addr + (tmpidx << PAGE_SHIFT),
 					VM_PAGE_TO_PHYS(p));
-				vm_page_unhold(p);
+				p->flags |= PG_MAPPED;
+				PAGE_WAKEUP(p);
 			}
 			objpgs -= 1;
 		}
@@ -1752,12 +1759,12 @@ pmap_object_init_pt(pmap, addr, object, pindex, size, limit)
 			    ((p->valid & VM_PAGE_BITS_ALL) == VM_PAGE_BITS_ALL) &&
 			    (p->busy == 0) &&
 			    (p->flags & (PG_BUSY | PG_FICTITIOUS)) == 0) {
-				vm_page_hold(p);
-				p->flags |= PG_MAPPED;
+				p->flags |= PG_BUSY;
 				pmap_enter_quick(pmap, 
 					addr + (tmpidx << PAGE_SHIFT),
 					VM_PAGE_TO_PHYS(p));
-				vm_page_unhold(p);
+				p->flags |= PG_MAPPED;
+				PAGE_WAKEUP(p);
 			}
 		}
 	}
@@ -1843,10 +1850,10 @@ pmap_prefault(pmap, addra, entry, object)
 			if (m->queue == PQ_CACHE) {
 				vm_page_deactivate(m);
 			}
-			vm_page_hold(m);
-			m->flags |= PG_MAPPED;
+			m->flags |= PG_BUSY;
 			pmap_enter_quick(pmap, addr, VM_PAGE_TO_PHYS(m));
-			vm_page_unhold(m);
+			m->flags |= PG_MAPPED;
+			PAGE_WAKEUP(m);
 		}
 	}
 }
@@ -1940,7 +1947,10 @@ pmap_copy(dst_pmap, src_pmap, dst_addr, len, src_addr)
 		while (addr < pdnxt) {
 			unsigned ptetemp;
 			ptetemp = *src_pte;
-			if (ptetemp) {
+			/*
+			 * we only virtual copy managed pages
+			 */
+			if ((ptetemp & PG_MANAGED) != 0) {
 				/*
 				 * We have to check after allocpte for the
 				 * pte still being around...  allocpte can