I had Next 09 booted on a powerpc box and was compiling a kernel.
That's when i ran into this oops.

Unable to handle kernel paging request for data at address 0x00000010.
Faulting instruction address: 0xc0000000002ee1b0...................
0:mon> e
cpu 0x0: Vector: 300 (Data Access) at [c0000000d6cf63c0]
    pc: c0000000002ee1b0: .rb_erase+0x16c/0x3b4
    lr: c0000000002e14d0: .cfq_prio_tree_add+0x58/0x120
    sp: c0000000d6cf6640
   msr: 8000000000009032
   dar: 10
 dsisr: 40000000
  current = 0xc0000000fbdf5880
  paca    = 0xc000000000a92300
   pid   = 1867, comm = ld
0:mon> t
[c0000000d6cf66d0] c0000000002e14d0 .cfq_prio_tree_add+0x58/0x120
[c0000000d6cf6770] c0000000002e16c8 .__cfq_slice_expired+0xc8/0x11c
[c0000000d6cf6800] c0000000002e3920 .cfq_insert_request+0x374/0x3f4
[c0000000d6cf68a0] c0000000002cf448 .elv_insert+0x234/0x348
[c0000000d6cf6940] c0000000002d3348 .__make_request+0x514/0x5b0
[c0000000d6cf6a00] c0000000002d1348 .generic_make_request+0x430/0x4c8
[c0000000d6cf6b30] c0000000002d14dc .submit_bio+0xfc/0x124
[c0000000d6cf6bf0] c000000000156998 .submit_bh+0x14c/0x198
[c0000000d6cf6c80] c00000000015ba78 .block_read_full_page+0x394/0x40c
[c0000000d6cf7180] c000000000163080 .do_mpage_readpage+0x680/0x688
[c0000000d6cf7690] c000000000163200 .mpage_readpages+0x104/0x190
[c0000000d6cf77f0] c0000000001e2aac .ext3_readpages+0x28/0x40
[c0000000d6cf7870] c0000000000ebd20 .__do_page_cache_readahead+0x180/0x278
[c0000000d6cf7960] c0000000000ec16c .ondemand_readahead+0x1ac/0x1d8
[c0000000d6cf7a00] c0000000000e1f28 .generic_file_aio_read+0x260/0x6b0
[c0000000d6cf7b40] c000000000129f74 .do_sync_read+0xcc/0x130
[c0000000d6cf7ce0] c00000000012af44 .vfs_read+0xd0/0x1bc
[c0000000d6cf7d80] c00000000012b138 .SyS_read+0x58/0xa0
[c0000000d6cf7e30] c0000000000084ac syscall_exit+0x0/0x40
--- Exception: c01 (System Call) at 000004000050a854
SP (fffd455e850) is in userspace
0:mon> di %pc
c0000000002ee1b0  e95f0010      ld      r10,16(r31)
c0000000002ee1b4  7faa4000      cmpd    cr7,r10,r8
c0000000002ee1b8  409e00ec      bne     cr7,c0000000002ee2a4    # .rb_erase+0x260/0x3b4
c0000000002ee1bc  e95f0008      ld      r10,8(r31)
c0000000002ee1c0  e80a0000      ld      r0,0(r10)
c0000000002ee1c4  780907e1      clrldi. r9,r0,63
c0000000002ee1c8  40820028      bne     c0000000002ee1f0        # .rb_erase+0x1ac/0x3b4
c0000000002ee1cc  60000001      ori     r0,r0,1
c0000000002ee1d0  7fe3fb78      mr      r3,r31
c0000000002ee1d4  7fa4eb78      mr      r4,r29
c0000000002ee1d8  f80a0000      std     r0,0(r10)
c0000000002ee1dc  e81f0000      ld      r0,0(r31)
c0000000002ee1e0  780007a4      rldicr  r0,r0,0,62
c0000000002ee1e4  f81f0000      std     r0,0(r31)
c0000000002ee1e8  4bfffbfd      bl      c0000000002edde4        # .__rb_rotate_left+0x0/0x7c
c0000000002ee1ec  e95f0008      ld      r10,8(r31)
0:mon> di %ld
invalid register name '%ld'
c0000000002ee1f0  e96a0010      ld      r11,16(r10)
c0000000002ee1f4  2fab0000      cmpdi   cr7,r11,0
c0000000002ee1f8  419e0010      beq     cr7,c0000000002ee208    # .rb_erase+0x1c4/0x3b4
c0000000002ee1fc  e80b0000      ld      r0,0(r11)
c0000000002ee200  780907e1      clrldi. r9,r0,63
c0000000002ee204  4182001c      beq     c0000000002ee220        # .rb_erase+0x1dc/0x3b4
c0000000002ee208  e92a0008      ld      r9,8(r10)
c0000000002ee20c  2fa90000      cmpdi   cr7,r9,0
c0000000002ee210  419e00f4      beq     cr7,c0000000002ee304    # .rb_erase+0x2c0/0x3b4
c0000000002ee214  e8090000      ld      r0,0(r9)
c0000000002ee218  780907e1      clrldi. r9,r0,63
c0000000002ee21c  408200e8      bne     c0000000002ee304        # .rb_erase+0x2c0/0x3b4
c0000000002ee220  e92a0008      ld      r9,8(r10)
c0000000002ee224  2fa90000      cmpdi   cr7,r9,0
c0000000002ee228  419e0010      beq     cr7,c0000000002ee238    # .rb_erase+0x1f4/0x3b4
c0000000002ee22c  e8090000      ld      r0,0(r9)
0:mon>
R00 = c0000000fbc07330   R16 = c0000000006d2c92
R01 = c0000000d6cf6640   R17 = 0000000000000000
R02 = c0000000009986e8   R18 = 0000000000000004
R03 = c0000000f93620b0   R19 = c0000000d6cf6a90
R04 = c0000000fb8af038   R20 = c0000000d6cf6a70
R05 = fffffffffffffff0   R21 = 0000000000800000
R06 = 0000000000000001   R22 = 0000000004334ff2
R07 = c0000000f936a210   R23 = 0000000000800005
R08 = c0000000f936a210   R24 = c0000000fbaf0000
R09 = 0000000000000001   R25 = 0000000000000000
R10 = c0000000fbc09130   R26 = c0000000fbb0e490
R11 = 0000000000000000   R27 = c0000000fb8af000
R12 = c0000000dd7e3800   R28 = c0000000fb8af038
R13 = c000000000a92300   R29 = c0000000fb8af038
R14 = 0000000000010000   R30 = c000000000923360
R15 = 0000000000000001   R31 = 0000000000000000
pc  = c0000000002ee1b0 .rb_erase+0x16c/0x3b4
lr  = c0000000002e14d0 .cfq_prio_tree_add+0x58/0x120
msr = 8000000000009032   cr  = 44004448
ctr = c0000000002e35ac   xer = 0000000000000001   trap =  300
dar = 0000000000000010   dsisr = 40000000

On subsequent reboots, i observed similar oops during bootup.
I have attached the oops message here.

Let me know if i can provide any other information.

Thanks
-Sachin


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Sachin Sant
IBM Linux Technology Center
India Systems and Technology Labs
Bangalore, India
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