[BUG] 2.6.25-rc3-mm1 kernel bug while running libhugetlbfs

[Kamalesh Babulal <kamalesh@linux.vnet.ibm.com>]

Hi Andrew,

kernel bug is triggered while running libhugetlbfs test with 2.6.25-rc3-mm1 kernel
over the x86 and power machines.

------------[ cut here ]------------
kernel BUG at mm/hugetlb.c:295!
invalid opcode: 0000 [#1] SMP 
last sysfs file: /sys/devices/system/node/possible
Modules linked in:

Pid: 5484, comm: counters Not tainted (2.6.25-rc3-mm1-autokern1 #1)
EIP: 0060:[<c10535cf>] EFLAGS: 00010202 CPU: 0
EIP is at alloc_buddy_huge_page+0x7a/0xb0
EAX: c13acd01 EBX: f7d3a000 ECX: 00000000 EDX: 00006363
ESI: 00000001 EDI: 00000000 EBP: 00000000 ESP: f5539ebc
 DS: 007b ES: 007b FS: 00d8 GS: 0033 SS: 0068
Process counters (pid: 5484, ti=f5538000 task=f60afa20 task.ti=f5538000)
Stack: 00000001 c1053669 fffffff4 00000001 f5539ecc f5539ecc 00000001 fffffff4 
       f55d0e78 00000001 c105480c 00000001 00200000 c1054875 00000000 f54426c0 
       00200000 00000000 f54426c0 c10b0fb8 fffffff4 00200000 00000000 f55d0e78 
Call Trace:
 [<c1053669>] gather_surplus_pages+0x64/0x16d
 [<c105480c>] hugetlb_acct_memory+0x1e/0x4a
 [<c1054875>] hugetlb_reserve_pages+0x3d/0x6b
 [<c10b0fb8>] hugetlbfs_file_mmap+0x9b/0xe1
 [<c104bf9f>] mmap_region+0x1dc/0x3ae
 [<c104bd42>] do_mmap_pgoff+0x27f/0x28e
 [<c1005af2>] sys_mmap2+0x5a/0x78
 [<c10029fa>] syscall_call+0x7/0xb
 =======================
Code: c1 e8 ed 27 1c 00 85 db 74 41 83 7b 04 00 75 10 68 c0 93 27 c1 e8 02 92 fc ff 58 e8 c1 02 fb ff f0 ff 4b 04 0f 94 c0 84 c0 74 04 <0f> 0b eb fe c7 43 38 3e 33 05 c1 8b 03 c1 e8 1c ff 04 85 60 ce 
EIP: [<c10535cf>] alloc_buddy_huge_page+0x7a/0xb0 SS:ESP 0068:f5539ebc
---[ end trace 5a47484f8fe93a33 ]---


------------[ cut here ]------------
cpu 0x3: Vector: 700 (Program Check) at [c0000000fb277740]
    pc: c0000000000c6f54: .alloc_buddy_huge_page+0x120/0x1dc
    lr: c0000000000c6f20: .alloc_buddy_huge_page+0xec/0x1dc
    sp: c0000000fb2779c0
   msr: 8000000000029032
  current = 0xc0000000fc4cae90
  paca    = 0xc0000000004fae80
    pid   = 6828, comm = counters
kernel BUG at mm/hugetlb.c:295!
enter ? for help
[c0000000fb277a50] c0000000000c70e8 .hugetlb_acct_memory+0xd8/0x374
[c0000000fb277b10] c0000000000c769c .hugetlb_reserve_pages+0x184/0x2b0
[c0000000fb277bc0] c00000000018c950 .hugetlbfs_file_mmap+0xec/0x160
[c0000000fb277c70] c0000000000bc280 .mmap_region+0x254/0x4d4
[c0000000fb277d80] c00000000000b1b8 .sys_mmap+0xa4/0x104
[c0000000fb277e30] c00000000000872c syscall_exit+0x0/0x40
--- Exception: c01 (System Call) at 000004000019e528
SP (fffffcd4eb0) is in userspace
3:mon>
-- 
Thanks & Regards,
Kamalesh Babulal,
Linux Technology Center,
IBM, ISTL.