Hi,

Kernel exception is triggered on the powerpc while running kernbench with
sparsemem enabled.

cpu 0x3: Vector: 300 (Data Access) at [c00000077685b8c0]
    pc: 0000000000004570
    lr: 000000000ff1ab24
    sp: c00000077685bb40
   msr: 8000000000001000
   dar: c00000077685bce0
 dsisr: a000000
  current = 0xc00000077874f040
  paca    = 0xc0000000004a6880
    pid   = 13122, comm = cc1
WARNING: exception is not recoverable, can't continue
enter ? for help
[c00000077685bb40] c00000077685bbd0 (unreliable)
[c000000000518df8] c0000000005a7d40
[c0000000005f47ec] 0000000000000000 .__start+0x4000000000000000/0x8
SP (c0000000) is in userspace

3:mon>t
[c00000077685bb40] c00000077685bbd0 (unreliable)
[c000000000518df8] c0000000005a7d40
[c0000000005f47ec] 0000000000000000 .__start+0x4000000000000000/0x8
SP (c0000000) is in userspace

3:mon> S
msr  = 8000000000001032  sprg0= 0000000000000000
pvr  = 0000000000381300  sprg1= c0000000004a6880
dec  = 00000000d24a8b51  sprg2= 0000000000000000
sp   = c00000077685b0b0  sprg3= c0000000004a6880
toc  = c000000000578ea8  dar  = c00000077685bce0

3:mon> r
R00 = 0000000000004000   R16 = 0000000000000000
R01 = c00000077685bb40   R17 = 00000000101f0000
R02 = 0000000000000058   R18 = 00000000fff05060
R03 = 000000000000d032   R19 = 00000000101f0000
R04 = 0000000000000058   R20 = 00000000101e0000
R05 = 0000000000000400   R21 = 0000000000000000
R06 = 0000000000000000   R22 = 00000000101e0000
R07 = fffffffffeff0000   R23 = 00000000101f0000
R08 = 00000001f7fd948c   R24 = 00000000101f0000
R09 = 0000000044000828   R25 = 00000000101f0000
R10 = c00000077685be30   R26 = 00000000101f0000
R11 = 0000998be2321500   R27 = 00000000101f0000
R12 = 8000000000001030   R28 = 00000000101f0000
R13 = c0000000004a6880   R29 = 00000000f7fd9020
R14 = 00000000101f0000   R30 = 000000000ffeb71c
R15 = 0000000000000006   R31 = 000000000ffe4b40
pc  = 0000000000004570
lr  = 000000000ff1ab24
msr = 8000000000001000   cr  = 28000822
ctr = 000000000ff1ab04   xer = 0000000020000000   trap =  300
dar = c00000077685bce0   dsisr = 0a000000

-- 
Thanks & Regards,
Kamalesh Babulal,
Linux Technology Center,
IBM, ISTL.