ARM: fix rcu stalls on SMP platforms (7deabca0) · Commits · 戴 / test

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:

Russell King <rmk+kernel@arm.linux.org.uk>

arch/arm/kernel/smp.c

+8 −2

Original line number	Diff line number	Diff line
		@@ -443,9 +443,7 @@ static DEFINE_PER_CPU(struct clock_event_device, percpu_clockevent);
		static void ipi_timer(void)
		{
		struct clock_event_device *evt = &__get_cpu_var(percpu_clockevent);
		irq_enter();
		evt->event_handler(evt);
		irq_exit();
		}

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

		switch (ipinr) {
		case IPI_TIMER:
		irq_enter();
		ipi_timer();
		irq_exit();
		break;

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

		case IPI_CALL_FUNC:
		irq_enter();
		generic_smp_call_function_interrupt();
		irq_exit();
		break;

		case IPI_CALL_FUNC_SINGLE:
		irq_enter();
		generic_smp_call_function_single_interrupt();
		irq_exit();
		break;

		case IPI_CPU_STOP:
		irq_enter();
		ipi_cpu_stop(cpu);
		irq_exit();
		break;

		default:

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