Add an option "EXTRA_VNODES" to cause an extra number of vnode structures

to be allocated at boot time.  This is an expensive option, as they
consume physical ram and are not pageable etc.  In certain situations,
this kind of option is quite useful, especially for news servers that
access a large number of directories at random and torture the name cache.
Defining 5000 or 10000 extra vnodes should cut down the amount of vnode
recycling somewhat, which should allow better name and directory caching
etc.

This is a "your mileage may vary" option, with no real indication of
what works best for your machine except trial and error.  Too many will
cost you ram that you could otherwise use for disk buffers etc.

This is based on something John Dyson mentioned to me a while ago.

1 files changed, 6 insertions, 1 deletions

diff --git a/sys/kern/subr_param.c b/sys/kern/subr_param.c
index f86e749..92c06c1 100644
--- a/sys/kern/subr_param.c
+++ b/sys/kern/subr_param.c
@@ -36,7 +36,7 @@
  * SUCH DAMAGE.
  *
  *	@(#)param.c	8.3 (Berkeley) 8/20/94
- * $Id: param.c,v 1.18 1996/05/02 14:19:18 phk Exp $
+ * $Id: param.c,v 1.19 1996/05/10 19:28:32 wollman Exp $
  */
 
 #include "opt_sysvipc.h"
@@ -89,6 +89,11 @@ int	maxfiles = NPROC*2;			/* system wide open files limit */
 int	maxfilesperproc = NPROC*2;		/* per-process open files limit */
 int	ncallout = 16 + NPROC;			/* maximum # of timer events */
 
+#ifndef EXTRAVNODES
+#define EXTRAVNODES 0
+#endif
+int	extravnodes = EXTRAVNODES;		/* spare vnodes to allocate */
+
 /* maximum # of mbuf clusters */
 #ifndef NMBCLUSTERS
 #define	NMBCLUSTERS (512 + MAXUSERS * 16)