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Commit 8b5b773d authored by Richard Cochran's avatar Richard Cochran Committed by Ingo Molnar
Browse files

perf/x86/intel/rapl: Convert to hotplug state machine 



Install the callbacks via the state machine and let the core invoke
the callbacks on the already online CPUs.

Signed-off-by: default avatarRichard Cochran <rcochran@linutronix.de>
Signed-off-by: default avatarAnna-Maria Gleixner <anna-maria@linutronix.de>
Reviewed-by: default avatarSebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Huang Rui <ray.huang@amd.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: rt@linutronix.de
Link: http://lkml.kernel.org/r/20160713153334.008808086@linutronix.de


Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
parent 9744f7b7

arch/x86/events/intel/rapl.c

+25 −59
Original line number Diff line number Diff line
@@ -555,14 +555,14 @@ const struct attribute_group *rapl_attr_groups[] = { 
	NULL,

};



static void rapl_cpu_exit(int cpu)

static int rapl_cpu_offline(unsigned int cpu)

{

	struct rapl_pmu *pmu = cpu_to_rapl_pmu(cpu);

	int target;



	/* Check if exiting cpu is used for collecting rapl events */

	if (!cpumask_test_and_clear_cpu(cpu, &rapl_cpu_mask))

		return;

		return 0;



	pmu->cpu = -1;

	/* Find a new cpu to collect rapl events */
@@ -574,9 +574,10 @@ static void rapl_cpu_exit(int cpu) 
		pmu->cpu = target;

		perf_pmu_migrate_context(pmu->pmu, cpu, target);

	}

	return 0;

}



static void rapl_cpu_init(int cpu)

static int rapl_cpu_online(unsigned int cpu)

{

	struct rapl_pmu *pmu = cpu_to_rapl_pmu(cpu);

	int target;
@@ -587,13 +588,14 @@ static void rapl_cpu_init(int cpu) 
	 */

	target = cpumask_any_and(&rapl_cpu_mask, topology_core_cpumask(cpu));

	if (target < nr_cpu_ids)

		return;

		return 0;



	cpumask_set_cpu(cpu, &rapl_cpu_mask);

	pmu->cpu = cpu;

	return 0;

}



static int rapl_cpu_prepare(int cpu)

static int rapl_cpu_prepare(unsigned int cpu)

{

	struct rapl_pmu *pmu = cpu_to_rapl_pmu(cpu);
@@ -614,33 +616,6 @@ static int rapl_cpu_prepare(int cpu) 
	return 0;

}



static int rapl_cpu_notifier(struct notifier_block *self,

			     unsigned long action, void *hcpu)

{

	unsigned int cpu = (long)hcpu;



	switch (action & ~CPU_TASKS_FROZEN) {

	case CPU_UP_PREPARE:

		rapl_cpu_prepare(cpu);

		break;



	case CPU_DOWN_FAILED:

	case CPU_ONLINE:

		rapl_cpu_init(cpu);

		break;



	case CPU_DOWN_PREPARE:

		rapl_cpu_exit(cpu);

		break;

	}

	return NOTIFY_OK;

}



static struct notifier_block rapl_cpu_nb = {

	.notifier_call	= rapl_cpu_notifier,

	.priority       = CPU_PRI_PERF + 1,

};



static int rapl_check_hw_unit(bool apply_quirk)

{

	u64 msr_rapl_power_unit_bits;
@@ -691,24 +666,6 @@ static void __init rapl_advertise(void) 
	}

}



static int __init rapl_prepare_cpus(void)

{

	unsigned int cpu, pkg;

	int ret;



	for_each_online_cpu(cpu) {

		pkg = topology_logical_package_id(cpu);

		if (rapl_pmus->pmus[pkg])

			continue;



		ret = rapl_cpu_prepare(cpu);

		if (ret)

			return ret;

		rapl_cpu_init(cpu);

	}

	return 0;

}



static void cleanup_rapl_pmus(void)

{

	int i;
@@ -835,35 +792,44 @@ static int __init rapl_pmu_init(void) 
	if (ret)

		return ret;



	cpu_notifier_register_begin();

	/*

	 * Install callbacks. Core will call them for each online cpu.

	 */



	ret = rapl_prepare_cpus();

	ret = cpuhp_setup_state(CPUHP_PERF_X86_RAPL_PREP, "PERF_X86_RAPL_PREP",

				rapl_cpu_prepare, NULL);

	if (ret)

		goto out;



	ret = cpuhp_setup_state(CPUHP_AP_PERF_X86_RAPL_ONLINE,

				"AP_PERF_X86_RAPL_ONLINE",

				rapl_cpu_online, rapl_cpu_offline);

	if (ret)

		goto out1;



	ret = perf_pmu_register(&rapl_pmus->pmu, "power", -1);

	if (ret)

		goto out;

		goto out2;



	__register_cpu_notifier(&rapl_cpu_nb);

	cpu_notifier_register_done();

	rapl_advertise();

	return 0;



out2:

	cpuhp_remove_state(CPUHP_AP_PERF_X86_RAPL_ONLINE);

out1:

	cpuhp_remove_state(CPUHP_PERF_X86_RAPL_PREP);

out:

	pr_warn("Initialization failed (%d), disabled\n", ret);

	cleanup_rapl_pmus();

	cpu_notifier_register_done();

	return ret;

}

module_init(rapl_pmu_init);



static void __exit intel_rapl_exit(void)

{

	cpu_notifier_register_begin();

	__unregister_cpu_notifier(&rapl_cpu_nb);

	cpuhp_remove_state_nocalls(CPUHP_AP_PERF_X86_RAPL_ONLINE);

	cpuhp_remove_state_nocalls(CPUHP_PERF_X86_RAPL_PREP);

	perf_pmu_unregister(&rapl_pmus->pmu);

	cleanup_rapl_pmus();

	cpu_notifier_register_done();

}

module_exit(intel_rapl_exit);

include/linux/cpuhotplug.h

+2 −0
Original line number Diff line number Diff line
@@ -8,6 +8,7 @@ enum cpuhp_state { 
	CPUHP_PERF_X86_PREPARE,

	CPUHP_PERF_X86_UNCORE_PREP,

	CPUHP_PERF_X86_AMD_UNCORE_PREP,

	CPUHP_PERF_X86_RAPL_PREP,

	CPUHP_NOTIFY_PREPARE,

	CPUHP_BRINGUP_CPU,

	CPUHP_AP_IDLE_DEAD,
@@ -34,6 +35,7 @@ enum cpuhp_state { 
	CPUHP_AP_PERF_X86_ONLINE,

	CPUHP_AP_PERF_X86_UNCORE_ONLINE,

	CPUHP_AP_PERF_X86_AMD_UNCORE_ONLINE,

	CPUHP_AP_PERF_X86_RAPL_ONLINE,

	CPUHP_AP_NOTIFY_ONLINE,

	CPUHP_AP_ONLINE_DYN,

	CPUHP_AP_ONLINE_DYN_END		= CPUHP_AP_ONLINE_DYN + 30,