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, 5 insertions, 4 deletions

diff --git a/sys/gnu/fs/ext2fs/ext2_bmap.c b/sys/gnu/fs/ext2fs/ext2_bmap.c
index f3009bd..108a5aa 100644
--- a/sys/gnu/fs/ext2fs/ext2_bmap.c
+++ b/sys/gnu/fs/ext2fs/ext2_bmap.c
@@ -36,7 +36,7 @@
  * SUCH DAMAGE.
  *
  *	@(#)ufs_bmap.c	8.6 (Berkeley) 1/21/94
- * $Id: ufs_bmap.c,v 1.3 1994/08/02 07:54:52 davidg Exp $
+ * $Id: ufs_bmap.c,v 1.4 1994/10/08 06:57:21 phk Exp $
  */
 
 #include <sys/param.h>
@@ -128,12 +128,12 @@ ufs_bmaparray(vp, bn, bnp, ap, nump, runp)
 	if (runp) {
 		/*
 		 * XXX
-		 * If MAXBSIZE is the largest transfer the disks can handle,
+		 * If MAXPHYS is the largest transfer the disks can handle,
 		 * we probably want maxrun to be 1 block less so that we
 		 * don't create a block larger than the device can handle.
 		 */
 		*runp = 0;
-		maxrun = MAXBSIZE / mp->mnt_stat.f_iosize - 1;
+		maxrun = MAXPHYS / mp->mnt_stat.f_iosize - 1;
 	}
 
 	xap = ap == NULL ? a : ap;
@@ -179,7 +179,7 @@ ufs_bmaparray(vp, bn, bnp, ap, nump, runp)
 
 		xap->in_exists = 1;
 		bp = getblk(vp, metalbn, mp->mnt_stat.f_iosize, 0, 0);
-		if (bp->b_flags & (B_DONE | B_DELWRI)) {
+		if (bp->b_flags & B_CACHE) {
 			trace(TR_BREADHIT, pack(vp, size), metalbn);
 		}
 #ifdef DIAGNOSTIC
@@ -190,6 +190,7 @@ ufs_bmaparray(vp, bn, bnp, ap, nump, runp)
 			trace(TR_BREADMISS, pack(vp, size), metalbn);
 			bp->b_blkno = blkptrtodb(ump, daddr);
 			bp->b_flags |= B_READ;
+			vfs_busy_pages(bp, 0);
 			VOP_STRATEGY(bp);
 			curproc->p_stats->p_ru.ru_inblock++;	/* XXX */
 			error = biowait(bp);