From: deraadt <deraadt@openbsd.org>
Date: Mon, 24 Feb 1997 12:50:28 +0000 (+0000)
Subject: implement BUFCACHEPERCENT and take care with kva space
X-Git-Url: http://artulab.com/gitweb/?a=commitdiff_plain;h=a5ad1470ac91bae4cbb5789c8e5ef1491468300b;p=openbsd

implement BUFCACHEPERCENT and take care with kva space
---

diff --git a/sys/arch/powerpc/powerpc/machdep.c b/sys/arch/powerpc/powerpc/machdep.c
index fce1130babf..0eb035ec7fb 100644
--- a/sys/arch/powerpc/powerpc/machdep.c
+++ b/sys/arch/powerpc/powerpc/machdep.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: machdep.c,v 1.5 1997/02/05 01:33:54 rahnds Exp $	*/
+/*	$OpenBSD: machdep.c,v 1.6 1997/02/24 12:50:28 deraadt Exp $	*/
 /*	$NetBSD: machdep.c,v 1.4 1996/10/16 19:33:11 ws Exp $	*/
 
 /*
@@ -465,16 +465,29 @@ allocsys(v)
 	valloc(msqids, struct msqid_ds, msginfo.msgmni);
 #endif
 
+#ifndef BUFCACHEPERCENT
+#define BUFCACHEPERCENT 5
+#endif
 	/*
 	 * Decide on buffer space to use.
 	 */
 	if (bufpages == 0)
-		bufpages = (physmem / 20) / CLSIZE;
+		bufpages = (physmem / ((100/BUFCACHEPERCENT) / CLSIZE);
 	if (nbuf == 0) {
 		nbuf = bufpages;
 		if (nbuf < 16)
 			nbuf = 16;
 	}
+	/* Restrict to at most 70% filled kvm */
+	if (nbuf * MAXBSIZE >
+	    (VM_MAX_KERNEL_ADDRESS-VM_MIN_KERNEL_ADDRESS) * 7 / 10)
+		nbuf = (VM_MAX_KERNEL_ADDRESS-VM_MIN_KERNEL_ADDRESS) /
+		    MAXBSIZE * 7 / 10;
+
+	/* More buffer pages than fits into the buffers is senseless.  */
+	if (bufpages > nbuf * MAXBSIZE / CLBYTES)
+		bufpages = nbuf * MAXBSIZE / CLBYTES;
+
 	if (nswbuf == 0) {
 		nswbuf = (nbuf / 2) & ~1;
 		if (nswbuf > 256)