Issue

• RHEL5 or RHEL6 kernel crash with kblockd crashing inside _spin_lock_irqsave called from PowerGetSemaNew.
• Example of RHEL5 kernel 2.6.18-308.el5 crash

PID: 1127   TASK: ffff81203fb79860  CPU: 9   COMMAND: "kblockd/9"
 #0 [ffff81203f6e1b60] crash_kexec at ffffffff800b0938
 #1 [ffff81203f6e1c20] __die at ffffffff80065137
 #2 [ffff81203f6e1c60] die at ffffffff8006c789
 #3 [ffff81203f6e1c90] do_general_protection at ffffffff8006557f
 #4 [ffff81203f6e1cd0] error_exit at ffffffff8005dde9
    [exception RIP: _spin_lock_irqsave+3]
    RIP: ffffffff80064aeb  RSP: ffff81203f6e1d88  RFLAGS: 00010086
    RAX: 0000000000000286  RBX: 3032342c30303236  RCX: ffffffff8029f6f3
    RDX: 0000000000000000  RSI: 0000000000000001  RDI: 3032342c30303236
    RBP: 0000000000000001   R8: ffff810e7241e1e0   R9: ffff81203fb79860
    R10: ffff81184f99b300  R11: 0000000000000060  R12: ffff81201e96a008
    R13: ffff81201e96a030  R14: ffff81202890e0c8  R15: ffff81201e96a008
    ORIG_RAX: ffffffffffffffff  CS: 0010  SS: 0000
 #5 [ffff81203f6e1d88] PowerGetSemaNew at ffffffff885068e2 [emcp]
 #6 [ffff81203f6e1db8] PowerTopDispatch at ffffffff88508e70 [emcp]
 #7 [ffff81203f6e1de8] emcp_pseudo_strategy_request_fn at ffffffff8850d0ab [emcp]
 #8 [ffff81203f6e1e28] generic_unplug_device at ffffffff8005a464
 #9 [ffff81203f6e1e38] run_workqueue at ffffffff8004d2e4
#10 [ffff81203f6e1e78] worker_thread at ffffffff80049bdd
#11 [ffff81203f6e1ee8] kthread at ffffffff80032679
#12 [ffff81203f6e1f48] kernel_thread at ffffffff8005dfb1

• Example of RHEL6 kernel 2.6.32-358.el6 crash

PID: 154    TASK: ffff880c2cdb8ae0  CPU: 0   COMMAND: "kblockd/0"
 #0 [ffff880c2ce9f9d0] machine_kexec at ffffffff81035b7b
 #1 [ffff880c2ce9fa30] crash_kexec at ffffffff810c0db2
 #2 [ffff880c2ce9fb00] oops_end at ffffffff815111d0
 #3 [ffff880c2ce9fb30] die at ffffffff8100f19b
 #4 [ffff880c2ce9fb60] do_general_protection at ffffffff81510cd2
 #5 [ffff880c2ce9fb90] general_protection at ffffffff815104a5
    [exception RIP: _spin_lock_irqsave+31]
    RIP: ffffffff8150feaf  RSP: ffff880c2ce9fc40  RFLAGS: 00010086
    RAX: 0000000000010000  RBX: f570235003f12a2b  RCX: 00000000f6495faa
    RDX: 0000000000000286  RSI: 0000000000000001  RDI: f570235003f12a2b
    RBP: ffff880c2ce9fc40   R8: 0000000000000800   R9: 0000000000001000
    R10: 0000000000001000  R11: 0000000000000000  R12: 0000000000000001
    R13: ffff88182aaacf28  R14: ffff8801d2c40d00  R15: 0000000000000000
    ORIG_RAX: ffffffffffffffff  CS: 0010  SS: 0000
 #6 [ffff880c2ce9fc48] PowerGetSemaNew at ffffffffa04910bb [emcp]
 #7 [ffff880c2ce9fc78] PowerGetSema at ffffffffa04912d3 [emcp]
 #8 [ffff880c2ce9fc88] PowerPlatformBottomDispatch at ffffffffa0497b35 [emcp]
 #9 [ffff880c2ce9fce8] PowerBottomDispatch at ffffffffa0498088 [emcp]
#10 [ffff880c2ce9fd18] PowerBottomDispatchPirp at ffffffffa04983a9 [emcp]
#11 [ffff880c2ce9fd48] PowerTopDispatch at ffffffffa049dda0 [emcp]
#12 [ffff880c2ce9fd78] emcp_common_strategy_request_fn at ffffffffa049e116 [emcp]
#13 [ffff880c2ce9fdd8] emcp_pseudo_strategy_request_fn at ffffffffa049e3be [emcp]
#14 [ffff880c2ce9fdf8] __blk_run_queue at ffffffff8125b381
#15 [ffff880c2ce9fe18] cfq_kick_queue at ffffffff81270979
#16 [ffff880c2ce9fe38] worker_thread at ffffffff81090ac0
#17 [ffff880c2ce9fee8] kthread at ffffffff81096916
#18 [ffff880c2ce9ff48] kernel_thread at ffffffff8100c0ca