hi,

with kernel-2.6.0-test2-mm3+A3-O12.2int i found this in logs:

bad: scheduling while atomic!
Call Trace:
 [<c011c87d>] schedule+0x56d/0x580
 [<c0144b33>] unmap_page_range+0x43/0x70
 [<c0144d15>] unmap_vmas+0x1b5/0x210
 [<c014893b>] exit_mmap+0x7b/0x190
 [<c011e399>] mmput+0x79/0xf0
 [<c0122082>] do_exit+0x122/0x3f0
 [<c010b7c0>] do_invalid_op+0x0/0xd0
 [<c010b4d9>] die+0xf9/0x100
 [<c010b889>] do_invalid_op+0xc9/0xd0
 [<c01436ba>] kunmap_high+0x1a/0xa0
 [<c02a0f9f>] error_code+0x2f/0x38
 [<c01436ba>] kunmap_high+0x1a/0xa0
 [<c01a6040>] reiserfs_unprepare_pages+0x30/0x70
 [<c01a72b5>] reiserfs_file_write+0x4e5/0x595
 [<c011aa31>] do_page_fault+0x251/0x454
 [<c011c941>] __wake_up_common+0x31/0x60
 [<c01a6dd0>] reiserfs_file_write+0x0/0x595
 [<c0153e38>] vfs_write+0xb8/0x130
 [<c0153f62>] sys_write+0x42/0x70
 [<c02a0593>] syscall_call+0x7/0xb

and:

bad: scheduling while atomic!
Call Trace:
 [<c011c87d>] schedule+0x56d/0x580
 [<c01376a4>] __remove_from_page_cache+0x24/0x80
 [<c0140db8>] __pagevec_release+0x28/0x40
 [<c0141334>] truncate_inode_pages+0xc4/0x2b0
 [<c016e392>] iput+0x62/0x80
 [<c016b0e2>] dput+0x22/0x260
 [<c01561c1>] invalidate_inode_buffers+0x11/0x70
 [<c016e18b>] generic_delete_inode+0x13b/0x150
 [<c016e392>] iput+0x62/0x80
 [<c016b1dc>] dput+0x11c/0x260
 [<c0154ce5>] __fput+0xb5/0x120
 [<c0153362>] filp_close+0x82/0xb0
 [<c01214f4>] put_files_struct+0x54/0xc0
 [<c01220bd>] do_exit+0x15d/0x3f0
 [<c010b7c0>] do_invalid_op+0x0/0xd0
 [<c010b4d9>] die+0xf9/0x100
 [<c010b889>] do_invalid_op+0xc9/0xd0
 [<c01436ba>] kunmap_high+0x1a/0xa0
 [<c02a0f9f>] error_code+0x2f/0x38
 [<c01436ba>] kunmap_high+0x1a/0xa0
 [<c01a6040>] reiserfs_unprepare_pages+0x30/0x70
 [<c01a72b5>] reiserfs_file_write+0x4e5/0x595
 [<c011aa31>] do_page_fault+0x251/0x454
 [<c011c941>] __wake_up_common+0x31/0x60
 [<c01a6dd0>] reiserfs_file_write+0x0/0x595
 [<c0153e38>] vfs_write+0xb8/0x130
 [<c0153f62>] sys_write+0x42/0x70
 [<c02a0593>] syscall_call+0x7/0xb

there are many of those.
and one one kernel BUG report in the middle of them:

Error (regular_file): read_ksyms stat /proc/ksyms failed
ksymoops: No such file or directory
No modules in ksyms, skipping objects
No ksyms, skipping lsmod
kernel BUG at mm/highmem.c:178!
invalid operand: 0000 [#2]
CPU:    0
EIP:    0060:[<c01436ba>]    Not tainted VLI
Using defaults from ksymoops -t elf32-i386 -a i386
EFLAGS: 00210246
eax: 00000000   ebx: c19be060   ecx: c0394c90   edx: c0394c98
esi: 00000000   edi: e7e03ee4   ebp: 00000001   esp: e7e03e7c
ds: 007b   es: 007b   ss: 0068
Stack: c19be060 c19be060 c01a6040 c19be060 00000000 00000001 00000001
e3cfb678
       c01a72b5 e7e03ee4 00000001 00000000 00000001 00001000 e7e03ee4
00000001
       00000000 00001000 00000020 00000000 00001000 e3cfb6e4 ffffffe4
00000000
Call Trace:
 [<c01a6040>] reiserfs_unprepare_pages+0x30/0x70
 [<c01a72b5>] reiserfs_file_write+0x4e5/0x595
 [<c025fda0>] ip_rcv+0x330/0x450
 [<c011aa31>] do_page_fault+0x251/0x454
 [<c024bbbc>] skb_release_data+0x8c/0xa0
 [<c024bbf4>] kfree_skbmem+0x24/0x30
 [<c024bc82>] __kfree_skb+0x82/0x100
 [<c01a6dd0>] reiserfs_file_write+0x0/0x595
 [<c0153e38>] vfs_write+0xb8/0x130
 [<c0153f62>] sys_write+0x42/0x70
 [<c02a0593>] syscall_call+0x7/0xb
Code: 00 04 00 00 8b 0d a0 4b 39 c0 e9 ad fe ff ff 89 f6 53 ba 00 e0 ff ff


>>EIP; c01436ba <kunmap_high+1a/a0>   <=====

>>ebx; c19be060 <_end+160e328/3fc4d2c8>
>>ecx; c0394c90 <page_address_htable+d0/400>
>>edx; c0394c98 <page_address_htable+d8/400>
>>edi; e7e03ee4 <_end+27a541ac/3fc4d2c8>
>>esp; e7e03e7c <_end+27a54144/3fc4d2c8>

Trace; c01a6040 <reiserfs_unprepare_pages+30/70>
Trace; c01a72b5 <reiserfs_file_write+4e5/595>
Trace; c025fda0 <ip_rcv+330/450>
Trace; c011aa31 <do_page_fault+251/454>
Trace; c024bbbc <skb_release_data+8c/a0>
Trace; c024bbf4 <kfree_skbmem+24/30>
Trace; c024bc82 <__kfree_skb+82/100>
Trace; c01a6dd0 <reiserfs_file_write+0/595>
Trace; c0153e38 <vfs_write+b8/130>
Trace; c0153f62 <sys_write+42/70>
Trace; c02a0593 <syscall_call+7/b>

Code;  c01436ba <kunmap_high+1a/a0>
00000000 <_EIP>:
Code;  c01436ba <kunmap_high+1a/a0>   <=====
   0:   00 04 00                  add    %al,(%eax,%eax,1)   <=====
Code;  c01436bd <kunmap_high+1d/a0>
   3:   00 8b 0d a0 4b 39         add    %cl,0x394ba00d(%ebx)
Code;  c01436c3 <kunmap_high+23/a0>
   9:   c0 e9 ad                  shr    $0xad,%cl
Code;  c01436c6 <kunmap_high+26/a0>
   c:   fe                        (bad)
Code;  c01436c7 <kunmap_high+27/a0>
   d:   ff                        (bad)
Code;  c01436c8 <kunmap_high+28/a0>
   e:   ff 89 f6 53 ba 00         decl   0xba53f6(%ecx)
Code;  c01436ce <kunmap_high+2e/a0>
  14:   e0 ff                     loopne 15 <_EIP+0x15>
Code;  c01436d0 <kunmap_high+30/a0>
  16:   ff 00                     incl   (%eax)

XP2500+ on nF2 with 1GB of memory

l.