[src/trunk]: src/sys/kern Make this actually work if the BUFCACHE option is n...

[thorpej <thorpej%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/dce3023b0c5f
branches:  trunk
changeset: 473115:dce3023b0c5f
user:      thorpej <thorpej%NetBSD.org@localhost>
date:      Thu May 20 20:01:28 1999 +0000

description:
Make this actually work if the BUFCACHE option is not specified, by falling
back on the traditional BSD formula of 10% of first 2MB and 5% of remaining.

diffstat:

 sys/kern/kern_allocsys.c |  25 ++++++++++++++++++++-----
 1 files changed, 20 insertions(+), 5 deletions(-)

diffs (47 lines):

diff -r 01abe5f9fdd2 -r dce3023b0c5f sys/kern/kern_allocsys.c
--- a/sys/kern/kern_allocsys.c  Thu May 20 19:56:49 1999 +0000
+++ b/sys/kern/kern_allocsys.c  Thu May 20 20:01:28 1999 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: kern_allocsys.c,v 1.1 1999/05/20 05:59:52 lukem Exp $  */
+/*     $NetBSD: kern_allocsys.c,v 1.2 1999/05/20 20:01:28 thorpej Exp $        */
 
 /*-
  * Copyright (c) 1999 The NetBSD Foundation, Inc.
@@ -107,6 +107,7 @@
 #  error BUFCACHE is not between 5 and 95
 # endif
 #else
+  /* Default to 10% of first 2MB and 5% of remaining. */
 # define BUFCACHE 0
 #endif
 
@@ -151,11 +152,25 @@
 
        /*
         * Determine how many buffers to allocate.
-        * We allocate bufcache % of memory for buffer space.
+        *
+        *      - If bufcache is specified, use that % of memory
+        *        for the buffer cache.
+        *
+        *      - Otherwise, we default to the traditional BSD
+        *        formula of 10% of the first 2MB and 5% of
+        *        the remaining.
         */
-
-       if (bufpages == 0)
-               bufpages = physmem / CLSIZE * bufcache / 100;
+       if (bufpages == 0) {
+               if (bufcache != 0)
+                       bufpages = physmem / CLSIZE * bufcache / 100;
+               else {
+                       if (physmem < btoc(2 * 1024 * 1024))
+                               bufpages = physmem / (10 * CLSIZE);
+                       else
+                               bufpages = (btoc(2 * 1024 * 1024) + physmem) /
+                                   (20 * CLSIZE);
+               }
+       }
 
 #ifdef DIAGNOSTIC
        if (bufpages == 0)