Fix scheduling-while-atomic problem in console_cpu_notify()

The console_cpu_notify( function runs with interrupts disabled in the CPU_DEAD case. It therefore cannot block, for example, as will happen when it calls console_lock(). Therefore, remove the CPU_DEAD leg of the switch statement to avoid this problem.

Signed-off-by Paul E. McKenney <[email protected]>

Quoted 6 lines · Paul E. McKenney

The console_cpu_notify( function runs with interrupts disabled in the CPU_DEAD case. It therefore cannot block, for example, as will happen when it calls console_lock(). Therefore, remove the CPU_DEAD leg of the switch statement to avoid this problem.

Signed-off-by Paul E. McKenney <[email protected]>

s/CPU_DEAD/CPU_DYING/

Apparently it is a bad idea to compose and send a patch while in a C++ standards committee meeting where people are arguing about async futures... Fixed patch below.

Thanx, Paul

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printk: Fix scheduling-while-atomic problem in console_cpu_notify()

The console_cpu_notify( function runs with interrupts disabled in the CPU_DYING case. It therefore cannot block, for example, as will happen when it calls console_lock(). Therefore, remove the CPU_DYING leg of the switch statement to avoid this problem.

Signed-off-by Paul E. McKenney <[email protected]>

kernel/printk.c +0 -1

index 66a2ea3..2d607f4 100644
@@ -1890,7 +1890,6 @@ 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();