Otherwise we will get below warning: BUG: sleeping function called from invalid context at /build/linux/kernel/rtmutex.c:645 in_atomic(): 1, irqs_disabled(): 1, pid: 1054, name: migration/9 no locks held by migration/9/1054. irq event stamp: 36 hardirqs last enabled at (35): [<ffffffff815f5b50>] _raw_spin_unlock_irq+0x30/0x70 hardirqs last disabled at (36): [<ffffffff810b7eaf>] stop_machine_cpu_stop+0x8f/0x110 softirqs last enabled at (0): [<ffffffff81051b53>] copy_process+0x6d3/0x1640 softirqs last disabled at (0): [< (null)>] (null) Pid: 1054, comm: migration/9 Not tainted 3.2.0-rc1-rt2-11312-gbf51260-dirty #12 Call Trace: [<ffffffff81040c4e>] __might_sleep+0x12e/0x1e0 [<ffffffff815f4d24>] rt_spin_lock+0x24/0x60 [<ffffffff810c4aa2>] ? touch_nmi_watchdog+0x42/0x80 [<ffffffff813f58f3>] serial8250_console_write+0x143/0x150 [<ffffffff81054323>] __call_console_drivers+0x93/0xb0 [<ffffffff8105438c>] _call_console_drivers+0x4c/0x80 [<ffffffff8105448d>] console_unlock+0xcd/0x240 [<ffffffff815ef5ac>] console_cpu_notify+0x26/0x2d [<ffffffff81083744>] notifier_call_chain+0x84/0xf0 [<ffffffff810837be>] __raw_notifier_call_chain+0xe/0x10 [<ffffffff81055ac0>] __cpu_notify+0x20/0x40 [<ffffffff815de3e2>] take_cpu_down+0x32/0x40 [<ffffffff810b7eca>] stop_machine_cpu_stop+0xaa/0x110 [<ffffffff810b7e20>] ? stop_one_cpu+0x80/0x80 [<ffffffff810b7e20>] ? stop_one_cpu+0x80/0x80 [<ffffffff810b79be>] cpu_stopper_thread+0xce/0x1b0 [<ffffffff810b78f0>] ? wait_for_stop_done+0xa0/0xa0 [<ffffffff810b78f0>] ? wait_for_stop_done+0xa0/0xa0 [<ffffffff810430c9>] ? sub_preempt_count+0xa9/0xe0 [<ffffffff810b78f0>] ? wait_for_stop_done+0xa0/0xa0 [<ffffffff810b78f0>] ? wait_for_stop_done+0xa0/0xa0 [<ffffffff8107c096>] kthread+0xa6/0xb0 [<ffffffff810430c9>] ? sub_preempt_count+0xa9/0xe0 [<ffffffff815f5b5b>] ? _raw_spin_unlock_irq+0x3b/0x70 [<ffffffff815f8534>] kernel_thread_helper+0x4/0x10 [<ffffffff810423bc>] ? finish_task_switch+0x8c/0x110 [<ffffffff815f5b5b>] ? _raw_spin_unlock_irq+0x3b/0x70 [<ffffffff815f5f21>] ? retint_restore_args+0xe/0xe [<ffffffff8107bff0>] ? kthreadd+0x160/0x160 [<ffffffff815f8530>] ? gs_change+0xb/0xb CPU 9 is now offline Signed-off-by: Yong Zhang <yong.zhang0@xxxxxxxxx> --- kernel/printk.c | 1 - 1 files changed, 0 insertions(+), 1 deletions(-) diff --git a/kernel/printk.c b/kernel/printk.c index 535bc3b..ba0393e 100644 --- a/kernel/printk.c +++ b/kernel/printk.c @@ -1223,7 +1223,6 @@ static int __cpuinit console_cpu_notify(struct notifier_block *self, switch (action) { case CPU_ONLINE: case CPU_DEAD: - case CPU_DYING: case CPU_DOWN_FAILED: case CPU_UP_CANCELED: console_lock(); -- 1.7.5.4 -- To unsubscribe from this list: send the line "unsubscribe linux-rt-users" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html