In RHEL 6, duplicate kernel migration processes/threads are created after each suspend/resume cycle.

Issue

• Duplicate kernel migration threads appear after each suspend/resume cycle. Either the old threads are not re-used, or killed when new migration threads start.
• Messages log shows call trace including 'stop_machine_cpu_stop'.

migration/4   S 0000000000000004     0 18508      2 0x00000080
 ffff880417821df0 0000000000000046 0000000000000000 0000000000000000
 0000000000000000 00000000ffffffff 0000000000000000 0000000000000000
 ffff880412d75af8 ffff880417821fd8 000000000000fb88 ffff880412d75af8
Call Trace:
 [<ffffffff810ce810>] ? stop_machine_cpu_stop+0x0/0xf0
 [<ffffffff810ce5a5>] cpu_stopper_thread+0x125/0x1b0
 [<ffffffff8150e130>] ? thread_return+0x4e/0x76e
 [<ffffffff81063422>] ? default_wake_function+0x12/0x20
 [<ffffffff810ce480>] ? cpu_stopper_thread+0x0/0x1b0
 [<ffffffff81096a36>] kthread+0x96/0xa0
 [<ffffffff8100c0ca>] child_rip+0xa/0x20
 [<ffffffff810969a0>] ? kthread+0x0/0xa0
 [<ffffffff8100c0c0>] ? child_rip+0x0/0x20