decouple the allocated number of vnodes from the "desiredvnodes" variable

which is used to size a zillion other things that increasing excessively
has been shown to cause problems - so that we may incrementally look at
increasing those other things without making the kernel unusable.

This diff effectivly increases the number of vnodes back to the number
of buffers, as in the earlier dynamic buffer cache commits, without
increasing anything else (namecache, softdeps, etc. etc.)

ok pedro@ tedu@ art@ thib@

3 files changed, 16 insertions, 7 deletions

diff --git a/sys/kern/kern_sysctl.c b/sys/kern/kern_sysctl.c
index 794d1d853c6..7e2475ddfae 100644
--- a/sys/kern/kern_sysctl.c
+++ b/sys/kern/kern_sysctl.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: kern_sysctl.c,v 1.153 2007/05/29 00:17:32 thib Exp $	*/
+/*	$OpenBSD: kern_sysctl.c,v 1.154 2007/06/01 17:29:10 beck Exp $	*/
 /*	$NetBSD: kern_sysctl.c,v 1.17 1996/05/20 17:49:05 mrg Exp $	*/
 
 /*-
@@ -289,7 +289,7 @@ kern_sysctl(int *name, u_int namelen, void *oldp, size_t *oldlenp, void *newp,
 	case KERN_VERSION:
 		return (sysctl_rdstring(oldp, oldlenp, newp, version));
 	case KERN_MAXVNODES:
-		return(sysctl_int(oldp, oldlenp, newp, newlen, &desiredvnodes));
+		return(sysctl_int(oldp, oldlenp, newp, newlen, &maxvnodes));
 	case KERN_MAXPROC:
 		return (sysctl_int(oldp, oldlenp, newp, newlen, &maxproc));
 	case KERN_MAXFILES:
diff --git a/sys/kern/vfs_subr.c b/sys/kern/vfs_subr.c
index dac428b9d51..a8b6aba5047 100644
--- a/sys/kern/vfs_subr.c
+++ b/sys/kern/vfs_subr.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: vfs_subr.c,v 1.153 2007/05/31 17:00:51 tedu Exp $	*/
+/*	$OpenBSD: vfs_subr.c,v 1.154 2007/06/01 17:29:10 beck Exp $	*/
 /*	$NetBSD: vfs_subr.c,v 1.53 1996/04/22 01:39:13 christos Exp $	*/
 
 /*
@@ -105,6 +105,7 @@ void vfs_free_addrlist(struct netexport *);
 void vputonfreelist(struct vnode *);
 
 int vflush_vnode(struct vnode *, void *);
+int maxvnodes;
 
 #ifdef DEBUG
 void printlockedvnodes(void);
@@ -118,6 +119,13 @@ struct pool vnode_pool;
 void
 vntblinit(void)
 {
+	/* buffer cache may need a vnode for each buffer */
+	/* 
+	 * XXX note this is different from desiredvnodes, which is
+	 * XXX the old static value computed from MAXUSERS which is
+	 * XXX used for sizing may other subsystems (namecache, softdeps, etc)
+	 */
+	maxvnodes = bufpages;
 	pool_init(&vnode_pool, sizeof(struct vnode), 0, 0, 0, "vnodes",
 	    &pool_allocator_nointr);
 	TAILQ_INIT(&vnode_hold_list);
@@ -356,11 +364,11 @@ getnewvnode(enum vtagtype tag, struct mount *mp, int (**vops)(void *),
 	 * referencing buffers.
 	 */
 	toggle ^= 1;
-	if (numvnodes > 2 * desiredvnodes)
+	if (numvnodes > 2 * maxvnodes)
 		toggle = 0;
 
 	s = splbio();
-	if ((numvnodes < desiredvnodes) ||
+	if ((numvnodes < maxvnodes) ||
 	    ((TAILQ_FIRST(listhd = &vnode_free_list) == NULL) &&
 	    ((TAILQ_FIRST(listhd = &vnode_hold_list) == NULL) || toggle))) {
 		splx(s);
diff --git a/sys/sys/vnode.h b/sys/sys/vnode.h
index b4ad6836094..46c17791109 100644
--- a/sys/sys/vnode.h
+++ b/sys/sys/vnode.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: vnode.h,v 1.86 2007/05/31 18:22:25 thib Exp $	*/
+/*	$OpenBSD: vnode.h,v 1.87 2007/06/01 17:29:10 beck Exp $	*/
 /*	$NetBSD: vnode.h,v 1.38 1996/02/29 20:59:05 cgd Exp $	*/
 
 /*
@@ -238,7 +238,8 @@ extern struct freelst vnode_free_list;	/* vnode free list */
  * Global vnode data.
  */
 extern	struct vnode *rootvnode;	/* root (i.e. "/") vnode */
-extern	int desiredvnodes;		/* number of vnodes desired */
+extern	int desiredvnodes;		/* XXX number of vnodes desired */
+extern	int maxvnodes;			/* XXX number of vnodes to allocate */
 extern	time_t syncdelay;		/* time to delay syncing vnodes */
 extern	int rushjob;			/* # of slots syncer should run ASAP */
 #endif /* _KERNEL */