From 886d3e1150ddb85428a865fb90685c7c5090a678 Mon Sep 17 00:00:00 2001
From: John Dyson <dyson@FreeBSD.org>
Date: Sat, 8 Jun 1996 06:48:35 +0000
Subject: [PATCH] Adjust the threshold for blocking on movement of pages from
 the cache queue in vm_fault.

Move the PG_BUSY in vm_fault to the correct place.

Remove redundant/unnecessary code in pmap.c.

Properly block on rundown of page table pages, if they are busy.

I think that the VM system is in pretty good shape now, and the following
individuals (among others, in no particular order) have helped with this
recent bunch of bugs, thanks!  If I left anyone out, I apologize!

Stephen McKay, Stephen Hocking, Eric J. Chet, Dan O'Brien, James Raynard,
Marc Fournier.
---
 sys/amd64/amd64/pmap.c | 37 +++++++++++++------------------------
 sys/i386/i386/pmap.c   | 37 +++++++++++++------------------------
 sys/vm/vm_fault.c      |  9 ++++-----
 sys/vm/vm_page.c       |  5 ++---
 sys/vm/vm_page.h       |  3 ++-
 5 files changed, 34 insertions(+), 57 deletions(-)

diff --git a/sys/amd64/amd64/pmap.c b/sys/amd64/amd64/pmap.c
index 27a523618691..c96196da63bc 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 1.100 1996/06/05 06:36:21 dyson Exp $
+ *	$Id: pmap.c,v 1.101 1996/06/07 02:36:08 dyson Exp $
  */
 
 /*
@@ -730,17 +730,6 @@ pmap_release(pmap)
 	if (object->ref_count != 1)
 		panic("pmap_release: pteobj reference count != 1");
 	
-	/*
-	 * Wait until any (bogus) paging activity on this object is
-	 * complete.
-	 */
-	s = splvm();
-	while (object->paging_in_progress) {
-		object->flags |= OBJ_PIPWNT;
-		tsleep(object,PVM,"pmrlob",0);
-	}
-	splx(s);
-
 	ptdpg = NULL;
 retry:
 	for (p = TAILQ_FIRST(&object->memq); p != NULL; p = n) {
@@ -749,15 +738,14 @@ retry:
 			ptdpg = p;
 			continue;
 		}
-		if ((p->flags & PG_BUSY) || p->busy)
-			continue;
 		if (!pmap_release_free_page(pmap, p))
 			goto retry;
 	}
 	if (ptdpg == NULL)
 		panic("pmap_release: missing page table directory page");
 
-	pmap_release_free_page(pmap, ptdpg);
+	if (!pmap_release_free_page(pmap, ptdpg))
+		goto retry;
 
 	vm_object_deallocate(object);
 	if (pdstackptr < PDSTACKMAX) {
@@ -1173,7 +1161,11 @@ pmap_remove(pmap, sva, eva)
 	}
 }
 
-
+/*
+ * Remove pte mapping, don't do everything that we would do
+ * for normal pages because many things aren't necessary (like
+ * pmap_update())...
+ */	
 void
 pmap_remove_pte_mapping(pa)
 	vm_offset_t pa;
@@ -1189,7 +1181,6 @@ pmap_remove_pte_mapping(pa)
 		unsigned tpte;
 		struct pmap *pmap;
 
-		anyvalid = 1;
 		pmap = pv->pv_pmap;
 		pte = get_ptbase(pmap) + i386_btop(pv->pv_va);
 		if (tpte = *pte) {
@@ -1200,13 +1191,11 @@ pmap_remove_pte_mapping(pa)
 		}
 	}
 
-	if (anyvalid) {
-		for (pv = *ppv; pv; pv = npv) {
-			npv = pv->pv_next;
-			free_pv_entry(pv);
-		}
-		*ppv = NULL;
+	for (pv = *ppv; pv; pv = npv) {
+		npv = pv->pv_next;
+		free_pv_entry(pv);
 	}
+	*ppv = NULL;
 }
 
 /*
@@ -1221,7 +1210,7 @@ pmap_remove_pte_mapping(pa)
  *		inefficient because they iteratively called
  *		pmap_remove (slow...)
  */
-static __inline void
+static void
 pmap_remove_all(pa)
 	vm_offset_t pa;
 {
diff --git a/sys/i386/i386/pmap.c b/sys/i386/i386/pmap.c
index 27a523618691..c96196da63bc 100644
--- a/sys/i386/i386/pmap.c
+++ b/sys/i386/i386/pmap.c
@@ -39,7 +39,7 @@
  * SUCH DAMAGE.
  *
  *	from:	@(#)pmap.c	7.7 (Berkeley)	5/12/91
- *	$Id: pmap.c,v 1.100 1996/06/05 06:36:21 dyson Exp $
+ *	$Id: pmap.c,v 1.101 1996/06/07 02:36:08 dyson Exp $
  */
 
 /*
@@ -730,17 +730,6 @@ pmap_release(pmap)
 	if (object->ref_count != 1)
 		panic("pmap_release: pteobj reference count != 1");
 	
-	/*
-	 * Wait until any (bogus) paging activity on this object is
-	 * complete.
-	 */
-	s = splvm();
-	while (object->paging_in_progress) {
-		object->flags |= OBJ_PIPWNT;
-		tsleep(object,PVM,"pmrlob",0);
-	}
-	splx(s);
-
 	ptdpg = NULL;
 retry:
 	for (p = TAILQ_FIRST(&object->memq); p != NULL; p = n) {
@@ -749,15 +738,14 @@ retry:
 			ptdpg = p;
 			continue;
 		}
-		if ((p->flags & PG_BUSY) || p->busy)
-			continue;
 		if (!pmap_release_free_page(pmap, p))
 			goto retry;
 	}
 	if (ptdpg == NULL)
 		panic("pmap_release: missing page table directory page");
 
-	pmap_release_free_page(pmap, ptdpg);
+	if (!pmap_release_free_page(pmap, ptdpg))
+		goto retry;
 
 	vm_object_deallocate(object);
 	if (pdstackptr < PDSTACKMAX) {
@@ -1173,7 +1161,11 @@ pmap_remove(pmap, sva, eva)
 	}
 }
 
-
+/*
+ * Remove pte mapping, don't do everything that we would do
+ * for normal pages because many things aren't necessary (like
+ * pmap_update())...
+ */	
 void
 pmap_remove_pte_mapping(pa)
 	vm_offset_t pa;
@@ -1189,7 +1181,6 @@ pmap_remove_pte_mapping(pa)
 		unsigned tpte;
 		struct pmap *pmap;
 
-		anyvalid = 1;
 		pmap = pv->pv_pmap;
 		pte = get_ptbase(pmap) + i386_btop(pv->pv_va);
 		if (tpte = *pte) {
@@ -1200,13 +1191,11 @@ pmap_remove_pte_mapping(pa)
 		}
 	}
 
-	if (anyvalid) {
-		for (pv = *ppv; pv; pv = npv) {
-			npv = pv->pv_next;
-			free_pv_entry(pv);
-		}
-		*ppv = NULL;
+	for (pv = *ppv; pv; pv = npv) {
+		npv = pv->pv_next;
+		free_pv_entry(pv);
 	}
+	*ppv = NULL;
 }
 
 /*
@@ -1221,7 +1210,7 @@ pmap_remove_pte_mapping(pa)
  *		inefficient because they iteratively called
  *		pmap_remove (slow...)
  */
-static __inline void
+static void
 pmap_remove_all(pa)
 	vm_offset_t pa;
 {
diff --git a/sys/vm/vm_fault.c b/sys/vm/vm_fault.c
index ee4d92089768..d76fcc58444a 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 1.47 1996/05/31 00:37:56 dyson Exp $
+ * $Id: vm_fault.c,v 1.48 1996/06/01 20:50:57 dyson Exp $
  */
 
 /*
@@ -283,16 +283,15 @@ RetryFault:;
 			/*
 			 * Mark page busy for other processes, and the pagedaemon.
 			 */
-			m->flags |= PG_BUSY;
 			if ((m->queue == PQ_CACHE) &&
-			    (cnt.v_free_count + cnt.v_cache_count) < cnt.v_free_reserved) {
+			    (cnt.v_free_count + cnt.v_cache_count) < cnt.v_free_min) {
 				UNLOCK_AND_DEALLOCATE;
 				VM_WAIT;
-				PAGE_WAKEUP(m);
 				goto RetryFault;
 			}
 
-			vm_page_unqueue(m);
+			m->flags |= PG_BUSY;
+			vm_page_unqueue_nowakeup(m);
 
 			if (m->valid &&
 				((m->valid & VM_PAGE_BITS_ALL) != VM_PAGE_BITS_ALL) &&
diff --git a/sys/vm/vm_page.c b/sys/vm/vm_page.c
index 8b607cc53b74..47543fe830ed 100644
--- a/sys/vm/vm_page.c
+++ b/sys/vm/vm_page.c
@@ -34,7 +34,7 @@
  * SUCH DAMAGE.
  *
  *	from: @(#)vm_page.c	7.4 (Berkeley) 5/7/91
- *	$Id: vm_page.c,v 1.53 1996/05/31 00:38:03 dyson Exp $
+ *	$Id: vm_page.c,v 1.54 1996/06/05 03:31:48 dyson Exp $
  */
 
 /*
@@ -141,7 +141,6 @@ static inline __pure int
 		vm_page_hash __P((vm_object_t object, vm_pindex_t pindex))
 		__pure2;
 
-static void vm_page_unqueue_nowakeup __P((vm_page_t m));
 static int vm_page_freechk_and_unqueue __P((vm_page_t m));
 static void vm_page_free_wakeup __P((void));
 
@@ -526,7 +525,7 @@ vm_page_rename(m, new_object, new_pindex)
 /*
  * vm_page_unqueue without any wakeup
  */
-static __inline void
+__inline void
 vm_page_unqueue_nowakeup(m)
 	vm_page_t m;
 {
diff --git a/sys/vm/vm_page.h b/sys/vm/vm_page.h
index e11d02b78bb8..b27431663d98 100644
--- a/sys/vm/vm_page.h
+++ b/sys/vm/vm_page.h
@@ -61,7 +61,7 @@
  * any improvements or extensions that they make and grant Carnegie the
  * rights to redistribute these changes.
  *
- * $Id: vm_page.h,v 1.26 1996/05/18 04:00:18 dyson Exp $
+ * $Id: vm_page.h,v 1.27 1996/06/05 03:31:49 dyson Exp $
  */
 
 /*
@@ -251,6 +251,7 @@ vm_offset_t vm_page_startup __P((vm_offset_t, vm_offset_t, vm_offset_t));
 void vm_page_unwire __P((vm_page_t));
 void vm_page_wire __P((vm_page_t));
 void vm_page_unqueue __P((vm_page_t));
+void vm_page_unqueue_nowakeup __P((vm_page_t));
 void vm_page_set_validclean __P((vm_page_t, int, int));
 void vm_page_set_invalid __P((vm_page_t, int, int));
 static __inline boolean_t vm_page_zero_fill __P((vm_page_t));