Merge "Perf: stop counters when going into hotplug" (177e6160) · Commits · e / devices / android_kernel_sony_msm8994

arch/arm/kernel/perf_event_cpu.c

+43 −2

Original line number	Original line	Diff line number	Diff line
	@@ -211,6 +211,46 @@ static void armpmu_update_counters(void)
	}		}
	}		}

			static void armpmu_hotplug_enable(void *parm_pmu)
			{
			struct arm_pmu *armpmu = parm_pmu;
			struct pmu *pmu = &(armpmu->pmu);
			struct pmu_hw_events *hw_events = armpmu->get_hw_events();
			int idx;

			for (idx = 0; idx <= armpmu->num_events; ++idx) {
			struct perf_event *event = hw_events->events[idx];
			if (!event)
			continue;

			event->state = event->hotplug_save_state;
			pmu->start(event, 0);
			}
			}

			static void armpmu_hotplug_disable(void *parm_pmu)
			{
			struct arm_pmu *armpmu = parm_pmu;
			struct pmu *pmu = &(armpmu->pmu);
			struct pmu_hw_events *hw_events = armpmu->get_hw_events();
			int idx;

			for (idx = 0; idx <= armpmu->num_events; ++idx) {
			struct perf_event *event = hw_events->events[idx];
			if (!event)
			continue;

			event->hotplug_save_state = event->state;
			/*
			* Prevent timer tick handler perf callback from enabling
			* this event and potentially generating an interrupt
			* before the CPU goes down.
			*/
			event->state = PERF_EVENT_STATE_OFF;
			pmu->stop(event, 0);
			}
			}

	/*		/*
	* PMU hardware loses all context when a CPU goes offline.		* PMU hardware loses all context when a CPU goes offline.
	* When a CPU is hotplugged back in, since some hardware registers are		* When a CPU is hotplugged back in, since some hardware registers are
	@@ -243,7 +283,8 @@ static int __cpuinit cpu_pmu_notify(struct notifier_block *b,
	cpu_pmu->save_pm_registers, hcpu, 1);		cpu_pmu->save_pm_registers, hcpu, 1);
	if (cpu_pmu->pmu_state != ARM_PMU_STATE_OFF) {		if (cpu_pmu->pmu_state != ARM_PMU_STATE_OFF) {
	if (cpu_has_active_perf(cpu))		if (cpu_has_active_perf(cpu))
	armpmu_update_counters();		smp_call_function_single(cpu,
			armpmu_hotplug_disable, cpu_pmu, 1);
	/* Disarm the PMU IRQ before disappearing. */		/* Disarm the PMU IRQ before disappearing. */
	if (cpu_pmu->plat_device) {		if (cpu_pmu->plat_device) {
	irq = platform_get_irq(cpu_pmu->plat_device, 0);		irq = platform_get_irq(cpu_pmu->plat_device, 0);
	@@ -266,7 +307,7 @@ static int __cpuinit cpu_pmu_notify(struct notifier_block *b,
	enable_irq_callback(&irq);		enable_irq_callback(&irq);
	}		}
	if (cpu_has_active_perf(cpu)) {		if (cpu_has_active_perf(cpu)) {
	__get_cpu_var(from_idle) = 1;		armpmu_hotplug_enable(cpu_pmu);
	pmu = &cpu_pmu->pmu;		pmu = &cpu_pmu->pmu;
	pmu->pmu_enable(pmu);		pmu->pmu_enable(pmu);
	}		}

arch/arm/mach-msm/perf_debug.c

+1 −0

Original line number	Original line	Diff line number	Diff line
	@@ -49,6 +49,7 @@ static char *descriptions =
	"24 Perf: Add debugfs node to clear PMU\n"		"24 Perf: Add debugfs node to clear PMU\n"
	"25 msm: perf: reset perf cycle counter on krait\n"		"25 msm: perf: reset perf cycle counter on krait\n"
	"26 Perf: interrupt disable without bringing cpus up\n"		"26 Perf: interrupt disable without bringing cpus up\n"
			"27 Perf: stop counters when going into hotplug\n"
	;		;

	static ssize_t desc_read(struct file fp, char __user buf,		static ssize_t desc_read(struct file fp, char __user buf,

include/linux/perf_event.h

+1 −0

Original line number	Original line	Diff line number	Diff line
	@@ -319,6 +319,7 @@ struct perf_event {
	struct pmu *pmu;		struct pmu *pmu;

	enum perf_event_active_state state;		enum perf_event_active_state state;
			enum perf_event_active_state hotplug_save_state;
	unsigned int attach_state;		unsigned int attach_state;
	local64_t count;		local64_t count;
	atomic64_t child_count;		atomic64_t child_count;