Hi Andrew,

you wrote:
> ftp://ftp.kernel.org/pub/linux/kernel/people/akpm/
> patches/2.6/2.6.10-rc1/2.6.10-rc1-mm4/
> 
> - The 4-level-pagetable code is hopefully finalised.

Today I tested the linux-2.6.10-rc1-mm4 kernel and it works fine with the 
attached config. But if I enable HIGHPTE, that kernel hits following BUG 
(written down by hand) and panics when the INIT process is started:

kernel BUG at arch/i386/mm/highmem.c:63!
EIP is at kunmap_atomic+0x27/0x70
Call Trace
  show_stack+0xa6/0xb0
  show_register+0x14d/0x1c0
  die+0x158/0x2e0
  do_invalid_op+0xef/0x100
  error_code+0x2b/0x30
  copy_pte_range+0x122/0x490
  copy_pmd_range+0xc2/0xd0
  copy_pgd_range+0x68/0x90
  copy_page_range+0x54/0x60
  copy_mm+0x3e2/0x6b0
  copy_process+0x514/0x1320
  do_fork+0x63/0x1e3
  sys_fork+0x2d/0x30
  syscall_call+0x7/0xb

Regards
  Thomas Schlichter

P.S.: I'm not subscribed to LKML anymore, so please don't forget to CC me in 
your replies... ;-)