Commit 5bc73539 authored May 02, 2016 by Anna-Maria Gleixner Committed by Martin Schwidefsky May 03, 2016

s390/cpum_cf: Remove superfluous SMP function call



Since commit 3b9d6da6 ("cpu/hotplug: Fix rollback during error-out
in __cpu_disable()") it is ensured that callbacks of CPU_ONLINE and
CPU_DOWN_PREPARE are processed on the hotplugged CPU. Due to this SMP
function calls are no longer required.

Replace smp_call_function_single() with a direct call of
setup_pmc_cpu(). To keep the calling convention, interrupts are
explicitly disabled around the call.

Cc: linux-s390@vger.kernel.org
Signed-off-by: Anna-Maria Gleixner <anna-maria@linutronix.de>
Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

parent 7072276e

arch/s390/kernel/perf_cpum_cf.c

+6 −3

Original line number	Diff line number	Diff line
		@@ -665,18 +665,21 @@ static struct pmu cpumf_pmu = {
		static int cpumf_pmu_notifier(struct notifier_block *self, unsigned long action,
		void *hcpu)
		{
		unsigned int cpu = (long) hcpu;
		int flags;

		switch (action & ~CPU_TASKS_FROZEN) {
		case CPU_ONLINE:
		case CPU_DOWN_FAILED:
		flags = PMC_INIT;
		smp_call_function_single(cpu, setup_pmc_cpu, &flags, 1);
		local_irq_disable();
		setup_pmc_cpu(&flags);
		local_irq_enable();
		break;
		case CPU_DOWN_PREPARE:
		flags = PMC_RELEASE;
		smp_call_function_single(cpu, setup_pmc_cpu, &flags, 1);
		local_irq_disable();
		setup_pmc_cpu(&flags);
		local_irq_enable();
		break;
		default:
		break;