Memory upgrade and kernel panic

[tjm <tmollica@silcom.com>]

Hello.  Has anyone come across anything like this
before.  The system is a perfectly running Debian
2.2r2 with an AMD K6-2 500mhz with 256M mem (two
128M sdrams).  I swapped out the two sdrams and
installed one 256M sdram.  The bios sees the memory
OK and starts the boot process.  Linux evidently sees
the memory OK (line 2 below) but then gets to line
5 and spits out the rest and then the kernel panic
in line 22.  Can anyone shed any light on this or
am I right to assume that this is the result of a bad
memory module?

--------------------------------------------
1  Calibrating delay loop... 999.42 BogoMIPS
2  Memory: 257948k/262144k available (920k kernel code, 416k reserved,
2796 data, 64k init)
3  Dentry hash table entries: 32768 (order 6, 256k)
4  Buffer cache hash table entries: 262144 (order 8, 1024k)
5  Unable to handle kernel paging request at virtual address 7fff23a4
6  current->tss.cr3 = 00101000, %cr3 = 00101000
7  *pde = 00000000
8  Oops: 0002
9  CPU:    0
10  EIP:    0010:[<c011fba8>]
11  EFLAGS: 00010246
12  eax: 00000000   ebx: 00100000   ecx: 00000015   edx: 00000080
13  esi: 00000000   edi: 7fff23a4   ebp: 00000e00   esp: c01fdf48
14  ds: 0018   es: 0018   ss: 0018
15  Process swapper (pid: 0, process nr: 0, stackpage=c01fd000
16  Stack: cff00000 00000e00 0009b800 cfef8f8c c01fdf74 00000000
c01fdf7c c0210d3c
17         c010a409 c0113839 00040000 00000e00 c010a008 7fff23a4
00001c1d 00000000
18         0009b800 c0202666 c01c1c46 00000048 00000000 00002000
00000000 00000000
19  Call Trace: [<c010a409>] [<c0113839>] [<c010a008>] [<c01c1c46>]
[<c0106000>] [<c0106000>] 20 [<c0100175>] 
21  Code: f3 ab 8b 44 24 54 a8 03 74 23 83 c0 03 24 fc 89 44 24 54 83
22  Kernel panic: Attempted to kill the idle task!
23  In swapper task - not syncing
------------------------------------------------------

thanks,
-- 
tony mollica
tmollica@silcom.com