Subject: Re: UVM/other problems for desktop users in current?
To: Jukka Marin , Current Users <current-users@NetBSD.ORG>
From: John Franklin <franklin@elfie.org>
List: current-users
Date: 12/19/2002 16:13:12
On Thu, Dec 19, 2002 at 10:50:53PM +0200, Jukka Marin wrote:
> On Wed, Dec 18, 2002 at 10:14:27AM -0500, John Franklin wrote:
> > > The poor machine can't even handle one CVS operation without failing to
> > > serve files over NFS.  CPU usage on the server is less than 20% and
> > > there's over 300 MB of RAM available.
> > 
> > options BUFCACHE <30-50> on the server will clean that up.  BUFCACHE, if
> > unmodified, is 5% of your memory.  It's used for both NFS network
> > buffers and fs metadata buffers.  For NFS servers 5% is grossly
> > inadequate.  Watch systat bufcache (NFS buffers are charged to the root fs.)
> 
> Sure enough, 99% of buffers were allocated by root.  But, after setting
> 
> options        BUFCACHE=30
> 
> I could no longer boot:
> 
> cpu0: AMD Athlon Model 4 (Thunderbird) (686-class), 700.10 MHz
> cpu0: I-cache 64 KB 64b/line 2-way, D-cache 64 KB 64b/line 2-way
> cpu0: L2 cache 256 KB 64b/line 16-way
> cpu0: features 183f9ff<FPU,VME,DE,PSE,TSC,MSR,PAE,MCE,CX8,SEP,MTRR>
> cpu0: features 183f9ff<PGE,MCA,CMOV,FGPAT,PSE36,MMX>
> cpu0: features 183f9ff<FXSR>
> total memory = 511 MB
> panic: cpu_startup: cannot allocate VM for buffers
>
> So, _how_ do I make it allocate more buffers when BUFCACHE=30 causes a
> panic?
 
Weird.  Ok.  The BUFCACHE option represents the percentage of memory to
allocate to BUFCACHE.  30% of 511M is 153M.  I seem to have mine set to
25 (.25 * 446M = 111M).  I wonder if it can't handle more than 128M of
buffers.  Try cutting it down to 25 (127.75M) and see if you can boot.

Also, what kernel version are you running?  My dmesg is in a different
order: 

NetBSD 1.6K (DM.MP) #0: Sun Dec  8 05:35:41 EST 2002
    franklin@deathmitten:/usr/src2/sys/arch/i386/compile/DM.MP
total memory = 447 MB
avail memory = 323 MB
using 6144 buffers containing 111 MB of memory
BIOS32 rev. 0 found at 0xfb290
mainbus0 (root)
mainbus0: Intel MP Specification (Version 1.1) (OEM00000 PROD00000000)
cpu0 at mainbus0: apid 0 (boot processor)
cpu0: Intel Pentium II (Klamath) (686-class), 267.30 MHz, id 0x633
cpu0: features 80fbff<FPU,VME,DE,PSE,TSC,MSR,PAE,MCE,CX8,APIC,SEP,MTRR>
cpu0: features 80fbff<PGE,MCA,CMOV,MMX>

jf
-- 
John Franklin
franklin@elfie.org
ICBM: 3543'56"N 7853'27"W