>Number:         8954
>Category:       kern
>Synopsis:       buffer cache is too little when BUFCACHE is defined.
>Confidential:   yes
>Severity:       critical
>Priority:       high
>Responsible:    kern-bug-people (Kernel Bug People)
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Sun Dec  5 07:00:01 1999
>Last-Modified:
>Originator:     URA Hiroshi
>Organization:
>Release:        NetBSD-current (1999/12/05)
>Environment:
System: NetBSD satsuki.hiru.aoba.yokohama.jp 1.4P NetBSD 1.4P (SATSUKI) #5: Sun Dec  5 06:18:00 JST 1999 ura@satsuki.hiru.aoba.yokohama.jp:/usr/local/src/NetBSD/current/src/sys/arch/i386/compile/SATSUKI i386


>Description:

I found that buffer cache is too little.

NetBSD 1.4P (SATSUKI) #4: Sun Dec  5 06:18:00 JST 1999
    ura@satsuki:/usr/local/src/NetBSD/current/src/sys/arch/i386/compile/SATSUKI
cpu0: family 6 model 6 step 5
cpu0: Intel Pentium II (Celeron) (686-class)
total memory = 127 MB
avail memory = 122 MB
using 21 buffers containing 86016 of memory
BIOS32 rev. 0 found at 0xfb450
mainbus0 (root)

<snip.>

I define BUFCACHE option to my kernel config file.

>How-To-Repeat:

1. add your kernel configuration file to `options BUFCACHE 20'
2. recompile kernel
3. reboot machine using new kernel
4. see dmesg


>Fix:

Apply this patch.

Index: kern_allocsys.c
===================================================================
RCS file: /cvsroot/netbsd/syssrc/sys/kern/kern_allocsys.c,v
retrieving revision 1.6
diff -u -u -r1.6 kern_allocsys.c
--- kern_allocsys.c	1999/12/03 21:43:19	1.6
+++ kern_allocsys.c	1999/12/05 10:00:11
@@ -165,7 +165,7 @@
 			if (bufcache < 5 || bufcache > 95)
 				panic("bufcache is out of range (%d)\n",
 				    bufcache);
-			bufpages = physmem / bufcache / 100;
+			bufpages = physmem * bufcache / 100;
 
 		} else {
 			if (physmem < btoc(2 * 1024 * 1024))
>Audit-Trail:
>Unformatted: