These changes embody the support of the fully coherent merged VM buffer cache,

much higher filesystem I/O performance, and much better paging performance. It
represents the culmination of over 6 months of R&D.

The majority of the merged VM/cache work is by John Dyson.

The following highlights the most significant changes. Additionally, there are
(mostly minor) changes to the various filesystem modules (nfs, msdosfs, etc) to
support the new VM/buffer scheme.

vfs_bio.c:
Significant rewrite of most of vfs_bio to support the merged VM buffer cache
scheme.  The scheme is almost fully compatible with the old filesystem
interface.  Significant improvement in the number of opportunities for write
clustering.

vfs_cluster.c, vfs_subr.c
Upgrade and performance enhancements in vfs layer code to support merged
VM/buffer cache.  Fixup of vfs_cluster to eliminate the bogus pagemove stuff.

vm_object.c:
Yet more improvements in the collapse code.  Elimination of some windows that
can cause list corruption.

vm_pageout.c:
Fixed it, it really works better now.  Somehow in 2.0, some "enhancements"
broke the code.  This code has been reworked from the ground-up.

vm_fault.c, vm_page.c, pmap.c, vm_object.c
Support for small-block filesystems with merged VM/buffer cache scheme.

pmap.c vm_map.c
Dynamic kernel VM size, now we dont have to pre-allocate excessive numbers of
kernel PTs.

vm_glue.c
Much simpler and more effective swapping code.  No more gratuitous swapping.

proc.h
Fixed the problem that the p_lock flag was not being cleared on a fork.

swap_pager.c, vnode_pager.c
Removal of old vfs_bio cruft to support the past pseudo-coherency.  Now the
code doesn't need it anymore.

machdep.c
Changes to better support the parameter values for the merged VM/buffer cache
scheme.

machdep.c, kern_exec.c, vm_glue.c
Implemented a seperate submap for temporary exec string space and another one
to contain process upages. This eliminates all map fragmentation problems
that previously existed.

ffs_inode.c, ufs_inode.c, ufs_readwrite.c
Changes for merged VM/buffer cache.  Add "bypass" support for sneaking in on
busy buffers.

Submitted by:	John Dyson and David Greenman

1 files changed, 63 insertions, 62 deletions

diff --git a/sys/vm/vm_pager.c b/sys/vm/vm_pager.c
index d82ec25..be57e5e 100644
--- a/sys/vm/vm_pager.c
+++ b/sys/vm/vm_pager.c
@@ -1,4 +1,4 @@
-/* 
+/*
  * Copyright (c) 1991, 1993
  *	The Regents of the University of California.  All rights reserved.
  *
@@ -40,17 +40,17 @@
  * All rights reserved.
  *
  * Authors: Avadis Tevanian, Jr., Michael Wayne Young
- * 
+ *
  * Permission to use, copy, modify and distribute this software and
  * its documentation is hereby granted, provided that both the copyright
  * notice and this permission notice appear in all copies of the
  * software, derivative works or modified versions, and any portions
  * thereof, and that both notices appear in supporting documentation.
- * 
- * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS" 
- * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND 
+ *
+ * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
+ * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND
  * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
- * 
+ *
  * Carnegie Mellon requests users of this software to return to
  *
  *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
@@ -61,7 +61,7 @@
  * any improvements or extensions that they make and grant Carnegie the
  * rights to redistribute these changes.
  *
- * $Id: vm_pager.c,v 1.9 1994/12/19 00:02:56 davidg Exp $
+ * $Id: vm_pager.c,v 1.10 1994/12/23 04:56:51 davidg Exp $
  */
 
 /*
@@ -89,7 +89,7 @@ struct pagerops *pagertab[] = {
 	&vnodepagerops,		/* PG_VNODE */
 	&devicepagerops,	/* PG_DEV */
 };
-int npagers = sizeof (pagertab) / sizeof (pagertab[0]);
+int npagers = sizeof(pagertab) / sizeof(pagertab[0]);
 
 struct pagerops *dfltpagerops = NULL;	/* default pager */
 
@@ -120,7 +120,7 @@ vm_pager_init()
 	 */
 	for (pgops = pagertab; pgops < &pagertab[npagers]; pgops++)
 		if (pgops)
-			(*(*pgops)->pgo_init)();
+			(*(*pgops)->pgo_init) ();
 	if (dfltpagerops == NULL)
 		panic("no default pager");
 }
@@ -130,6 +130,7 @@ vm_pager_bufferinit()
 {
 	struct buf *bp;
 	int i;
+
 	bp = swbuf;
 	/*
 	 * Now set up swap and physical I/O buffer headers.
@@ -143,8 +144,8 @@ vm_pager_bufferinit()
 	bp->b_vnbufs.le_next = NOLIST;
 	bp->b_actf = NULL;
 
-	swapbkva = kmem_alloc_pageable( pager_map, nswbuf * MAXPHYS);
-	if( !swapbkva)
+	swapbkva = kmem_alloc_pageable(pager_map, nswbuf * MAXPHYS);
+	if (!swapbkva)
 		panic("Not enough pager_map VM space for physical buffers");
 }
 
@@ -165,34 +166,34 @@ vm_pager_allocate(type, handle, size, prot, off)
 
 	ops = (type == PG_DFLT) ? dfltpagerops : pagertab[type];
 	if (ops)
-		return ((*ops->pgo_alloc)(handle, size, prot, off));
+		return ((*ops->pgo_alloc) (handle, size, prot, off));
 	return (NULL);
 }
 
 void
 vm_pager_deallocate(pager)
-	vm_pager_t	pager;
+	vm_pager_t pager;
 {
 	if (pager == NULL)
 		panic("vm_pager_deallocate: null pager");
 
-	(*pager->pg_ops->pgo_dealloc)(pager);
+	(*pager->pg_ops->pgo_dealloc) (pager);
 }
 
 
 int
 vm_pager_get_pages(pager, m, count, reqpage, sync)
-	vm_pager_t	pager;
-	vm_page_t	*m;
-	int		count;
-	int		reqpage;
-	boolean_t	sync;
+	vm_pager_t pager;
+	vm_page_t *m;
+	int count;
+	int reqpage;
+	boolean_t sync;
 {
 	int i;
 
 	if (pager == NULL) {
-		for (i=0;i<count;i++) {
-			if( i != reqpage) {
+		for (i = 0; i < count; i++) {
+			if (i != reqpage) {
 				PAGE_WAKEUP(m[i]);
 				vm_page_free(m[i]);
 			}
@@ -200,35 +201,34 @@ vm_pager_get_pages(pager, m, count, reqpage, sync)
 		vm_page_zero_fill(m[reqpage]);
 		return VM_PAGER_OK;
 	}
-
-	if( pager->pg_ops->pgo_getpages == 0) {
-		for(i=0;i<count;i++) {
-			if( i != reqpage) {
+	if (pager->pg_ops->pgo_getpages == 0) {
+		for (i = 0; i < count; i++) {
+			if (i != reqpage) {
 				PAGE_WAKEUP(m[i]);
 				vm_page_free(m[i]);
 			}
 		}
-		return(VM_PAGER_GET(pager, m[reqpage], sync));
+		return (VM_PAGER_GET(pager, m[reqpage], sync));
 	} else {
-		return(VM_PAGER_GET_MULTI(pager, m, count, reqpage, sync));
+		return (VM_PAGER_GET_MULTI(pager, m, count, reqpage, sync));
 	}
 }
 
 int
 vm_pager_put_pages(pager, m, count, sync, rtvals)
-	vm_pager_t	pager;
-	vm_page_t	*m;
-	int		count;
-	boolean_t	sync;
-	int		*rtvals;
+	vm_pager_t pager;
+	vm_page_t *m;
+	int count;
+	boolean_t sync;
+	int *rtvals;
 {
 	int i;
 
-	if( pager->pg_ops->pgo_putpages)
-		return(VM_PAGER_PUT_MULTI(pager, m, count, sync, rtvals));
+	if (pager->pg_ops->pgo_putpages)
+		return (VM_PAGER_PUT_MULTI(pager, m, count, sync, rtvals));
 	else {
-		for(i=0;i<count;i++) {
-			rtvals[i] = VM_PAGER_PUT( pager, m[i], sync);
+		for (i = 0; i < count; i++) {
+			rtvals[i] = VM_PAGER_PUT(pager, m[i], sync);
 		}
 		return rtvals[0];
 	}
@@ -236,12 +236,12 @@ vm_pager_put_pages(pager, m, count, sync, rtvals)
 
 boolean_t
 vm_pager_has_page(pager, offset)
-	vm_pager_t	pager;
-	vm_offset_t	offset;
+	vm_pager_t pager;
+	vm_offset_t offset;
 {
 	if (pager == NULL)
 		panic("vm_pager_has_page: null pager");
-	return ((*pager->pg_ops->pgo_haspage)(pager, offset));
+	return ((*pager->pg_ops->pgo_haspage) (pager, offset));
 }
 
 /*
@@ -255,37 +255,37 @@ vm_pager_sync()
 
 	for (pgops = pagertab; pgops < &pagertab[npagers]; pgops++)
 		if (pgops)
-			(*(*pgops)->pgo_putpage)(NULL, NULL, 0);
+			(*(*pgops)->pgo_putpage) (NULL, NULL, 0);
 }
 
 #if 0
 void
 vm_pager_cluster(pager, offset, loff, hoff)
-	vm_pager_t	pager;
-	vm_offset_t	offset;
-	vm_offset_t	*loff;
-	vm_offset_t	*hoff;
+	vm_pager_t pager;
+	vm_offset_t offset;
+	vm_offset_t *loff;
+	vm_offset_t *hoff;
 {
 	if (pager == NULL)
 		panic("vm_pager_cluster: null pager");
-	return ((*pager->pg_ops->pgo_cluster)(pager, offset, loff, hoff));
+	return ((*pager->pg_ops->pgo_cluster) (pager, offset, loff, hoff));
 }
 #endif
 
 vm_offset_t
 vm_pager_map_page(m)
-	vm_page_t	m;
+	vm_page_t m;
 {
 	vm_offset_t kva;
 
 	kva = kmem_alloc_wait(pager_map, PAGE_SIZE);
 	pmap_kenter(kva, VM_PAGE_TO_PHYS(m));
-	return(kva);
+	return (kva);
 }
 
 void
 vm_pager_unmap_page(kva)
-	vm_offset_t	kva;
+	vm_offset_t kva;
 {
 	pmap_kremove(kva);
 	kmem_free_wakeup(pager_map, kva, PAGE_SIZE);
@@ -293,11 +293,11 @@ vm_pager_unmap_page(kva)
 
 vm_page_t
 vm_pager_atop(kva)
-	vm_offset_t	kva;
+	vm_offset_t kva;
 {
 	vm_offset_t pa;
 
-	pa = pmap_kextract( kva);
+	pa = pmap_kextract(kva);
 	if (pa == 0)
 		panic("vm_pager_atop");
 	return (PHYS_TO_VM_PAGE(pa));
@@ -322,8 +322,8 @@ vm_pager_lookup(pglist, handle)
  */
 int
 pager_cache(object, should_cache)
-	vm_object_t	object;
-	boolean_t	should_cache;
+	vm_object_t object;
+	boolean_t should_cache;
 {
 	if (object == NULL)
 		return (KERN_INVALID_ARGUMENT);
@@ -343,10 +343,11 @@ pager_cache(object, should_cache)
 }
 
 /*
- * allocate a physical buffer 
+ * allocate a physical buffer
  */
 struct buf *
-getpbuf() {
+getpbuf()
+{
 	int s;
 	struct buf *bp;
 
@@ -354,7 +355,7 @@ getpbuf() {
 	/* get a bp from the swap buffer header pool */
 	while ((bp = bswlist.tqh_first) == NULL) {
 		bswneeded = 1;
-		tsleep((caddr_t)&bswneeded, PVM, "wswbuf", 0); 
+		tsleep((caddr_t) & bswneeded, PVM, "wswbuf", 0);
 	}
 	TAILQ_REMOVE(&bswlist, bp, b_freelist);
 	splx(s);
@@ -362,7 +363,7 @@ getpbuf() {
 	bzero(bp, sizeof *bp);
 	bp->b_rcred = NOCRED;
 	bp->b_wcred = NOCRED;
-	bp->b_data = (caddr_t) (MAXPHYS * (bp-swbuf)) + swapbkva;
+	bp->b_data = (caddr_t) (MAXPHYS * (bp - swbuf)) + swapbkva;
 	bp->b_vnbufs.le_next = NOLIST;
 	return bp;
 }
@@ -371,7 +372,8 @@ getpbuf() {
  * allocate a physical buffer, if one is available
  */
 struct buf *
-trypbuf() {
+trypbuf()
+{
 	int s;
 	struct buf *bp;
 
@@ -386,7 +388,7 @@ trypbuf() {
 	bzero(bp, sizeof *bp);
 	bp->b_rcred = NOCRED;
 	bp->b_wcred = NOCRED;
-	bp->b_data = (caddr_t) (MAXPHYS * (bp-swbuf)) + swapbkva;
+	bp->b_data = (caddr_t) (MAXPHYS * (bp - swbuf)) + swapbkva;
 	bp->b_vnbufs.le_next = NOLIST;
 	return bp;
 }
@@ -410,18 +412,17 @@ relpbuf(bp)
 		crfree(bp->b_wcred);
 		bp->b_wcred = NOCRED;
 	}
-
 	if (bp->b_vp)
-		brelvp(bp);
+		pbrelvp(bp);
 
 	if (bp->b_flags & B_WANTED)
-		wakeup((caddr_t)bp);
+		wakeup((caddr_t) bp);
 
 	TAILQ_INSERT_HEAD(&bswlist, bp, b_freelist);
 
 	if (bswneeded) {
 		bswneeded = 0;
-		wakeup((caddr_t)&bswlist);
+		wakeup((caddr_t) & bswlist);
 	}
 	splx(s);
 }