Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 7deabca0 authored by Russell King's avatar Russell King
Browse files

ARM: fix rcu stalls on SMP platforms 



We can stall RCU processing on SMP platforms if a CPU sits in its idle
loop for a long time.  This happens because we don't call irq_enter()
and irq_exit() around generic_smp_call_function_interrupt() and
friends.  Add the necessary calls, and remove the one from within
ipi_timer(), so that they're all in a common place.

Signed-off-by: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
parent 94ae0275

arch/arm/kernel/smp.c

+8 −2
Original line number Original line Diff line number Diff line
@@ -443,9 +443,7 @@ static DEFINE_PER_CPU(struct clock_event_device, percpu_clockevent); 
static void ipi_timer(void)

static void ipi_timer(void)

{

{

	struct clock_event_device *evt = &__get_cpu_var(percpu_clockevent);

	struct clock_event_device *evt = &__get_cpu_var(percpu_clockevent);

	irq_enter();

	evt->event_handler(evt);

	evt->event_handler(evt);

	irq_exit();

}

}





#ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST

#ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST
@@ -548,7 +546,9 @@ void handle_IPI(int ipinr, struct pt_regs *regs) 




	switch (ipinr) {

	switch (ipinr) {

	case IPI_TIMER:

	case IPI_TIMER:

		irq_enter();

		ipi_timer();

		ipi_timer();

		irq_exit();

		break;

		break;





	case IPI_RESCHEDULE:

	case IPI_RESCHEDULE:
@@ -556,15 +556,21 @@ void handle_IPI(int ipinr, struct pt_regs *regs) 
		break;

		break;





	case IPI_CALL_FUNC:

	case IPI_CALL_FUNC:

		irq_enter();

		generic_smp_call_function_interrupt();

		generic_smp_call_function_interrupt();

		irq_exit();

		break;

		break;





	case IPI_CALL_FUNC_SINGLE:

	case IPI_CALL_FUNC_SINGLE:

		irq_enter();

		generic_smp_call_function_single_interrupt();

		generic_smp_call_function_single_interrupt();

		irq_exit();

		break;

		break;





	case IPI_CPU_STOP:

	case IPI_CPU_STOP:

		irq_enter();

		ipi_cpu_stop(cpu);

		ipi_cpu_stop(cpu);

		irq_exit();

		break;

		break;





	default:

	default: