Issue

• Northbridge error on AMD CPU are logged and system caused a crash

• In vmcore, the logs below are logged.

  [Hardware Error]: CPU:0 MC4_STATUS[-|UE|-|PCC|-]: 0xb200000000070f0f
  [Hardware Error]: Northbridge Error (node 0): Watchdog timeout due to lack of progress.
  [Hardware Error]: cache level: L3/GEN, mem/io: GEN, mem-tx: GEN, part-proc: GEN (timed out)
  [Hardware Error]: CPU 0: Machine Check Exception: 4 Bank 4: b200000000070f0f
  [Hardware Error]: TSC 7c820464d79 
  [Hardware Error]: PROCESSOR 2:20f51 TIME 1408009657 SOCKET 0 APIC 0
  [Hardware Error]: CPU:0 MC4_STATUS[-|UE|-|PCC|-]: 0xb200000000070f0f
  [Hardware Error]: Northbridge Error (node 0): Watchdog timeout due to lack of progress.
  [Hardware Error]: cache level: L3/GEN, mem/io: GEN, mem-tx: GEN, part-proc: GEN (timed out)
  [Hardware Error]: Machine check: Processor context corrupt
  Kernel panic - not syncing: Fatal machine check on current CPU
  Pid: 3935, comm: sshd Tainted: G   M       ---------------    2.6.32-431.23.3.el6.x86_64 #1
  Call Trace:
   <#MC>  [<ffffffff815284fc>] ? panic+0xa7/0x16f
   [<ffffffff8102880f>] ? mce_panic+0x20f/0x230
   [<ffffffff81029c87>] ? do_machine_check+0x7a7/0xaf0
   [<ffffffff8152bb2c>] ? machine_check+0x1c/0x30
   [<ffffffffa038a90b>] ? rtl8169_interrupt+0x1b/0x80 [r8169]
   <<EOE>>  <IRQ>  [<ffffffff810e6d40>] ? handle_IRQ_event+0x60/0x170
   [<ffffffff810e97c8>] ? handle_fasteoi_irq+0x88/0xf0
   [<ffffffff8100c30c>] ? call_softirq+0x1c/0x30
   [<ffffffff8100faf9>] ? handle_irq+0x49/0xa0
   [<ffffffff815322cc>] ? do_IRQ+0x6c/0xf0
   [<ffffffff8100b9d3>] ? ret_from_intr+0x0/0x11
   <EOI>