Commit 3bf101ba authored by Matt Fleming's avatar Matt Fleming Committed by Robert Richter
Browse files

perf: Add helper function to return number of counters 



The number of counters for the registered pmu is needed in a few places
so provide a helper function that returns this number.

Signed-off-by: default avatarMatt Fleming <matt@console-pimps.org>
Tested-by: default avatarWill Deacon <will.deacon@arm.com>
Acked-by: default avatarPaul Mundt <lethal@linux-sh.org>
Acked-by: default avatarPeter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: default avatarRobert Richter <robert.richter@amd.com>
parent 4cbe75be

arch/arm/kernel/perf_event.c

+6 −0
Original line number Diff line number Diff line
@@ -123,6 +123,12 @@ armpmu_get_max_events(void) 
}

EXPORT_SYMBOL_GPL(armpmu_get_max_events);



int perf_num_counters(void)

{

	return armpmu_get_max_events();

}

EXPORT_SYMBOL_GPL(perf_num_counters);



#define HW_OP_UNSUPPORTED		0xFFFF



#define C(_x) \

arch/arm/oprofile/common.c

+18 −13
Original line number Diff line number Diff line
@@ -43,7 +43,7 @@ static DEFINE_MUTEX(op_arm_mutex); 


static struct op_counter_config *counter_config;

static struct perf_event **perf_events[nr_cpumask_bits];

static int perf_num_counters;

static int num_counters;



/*

 * Overflow callback for oprofile.
@@ -54,11 +54,11 @@ static void op_overflow_handler(struct perf_event *event, int unused, 
	int id;

	u32 cpu = smp_processor_id();



	for (id = 0; id < perf_num_counters; ++id)

	for (id = 0; id < num_counters; ++id)

		if (perf_events[cpu][id] == event)

			break;



	if (id != perf_num_counters)

	if (id != num_counters)

		oprofile_add_sample(regs, id);

	else

		pr_warning("oprofile: ignoring spurious overflow "
@@ -76,7 +76,7 @@ static void op_perf_setup(void) 
	u32 size = sizeof(struct perf_event_attr);

	struct perf_event_attr *attr;



	for (i = 0; i < perf_num_counters; ++i) {

	for (i = 0; i < num_counters; ++i) {

		attr = &counter_config[i].attr;

		memset(attr, 0, size);

		attr->type		= PERF_TYPE_RAW;
@@ -131,7 +131,7 @@ static int op_perf_start(void) 
	int cpu, event, ret = 0;



	for_each_online_cpu(cpu) {

		for (event = 0; event < perf_num_counters; ++event) {

		for (event = 0; event < num_counters; ++event) {

			ret = op_create_counter(cpu, event);

			if (ret)

				goto out;
@@ -150,7 +150,7 @@ static void op_perf_stop(void) 
	int cpu, event;



	for_each_online_cpu(cpu)

		for (event = 0; event < perf_num_counters; ++event)

		for (event = 0; event < num_counters; ++event)

			op_destroy_counter(cpu, event);

}
@@ -179,7 +179,7 @@ static int op_arm_create_files(struct super_block *sb, struct dentry *root) 
{

	unsigned int i;



	for (i = 0; i < perf_num_counters; i++) {

	for (i = 0; i < num_counters; i++) {

		struct dentry *dir;

		char buf[4];
@@ -353,14 +353,19 @@ int __init oprofile_arch_init(struct oprofile_operations *ops) 


	memset(&perf_events, 0, sizeof(perf_events));



	perf_num_counters = armpmu_get_max_events();

	num_counters = perf_num_counters();

	if (num_counters <= 0) {

		pr_info("oprofile: no performance counters\n");

		ret = -ENODEV;

		goto out;

	}



	counter_config = kcalloc(perf_num_counters,

	counter_config = kcalloc(num_counters,

			sizeof(struct op_counter_config), GFP_KERNEL);



	if (!counter_config) {

		pr_info("oprofile: failed to allocate %d "

				"counters\n", perf_num_counters);

				"counters\n", num_counters);

		ret = -ENOMEM;

		goto out;

	}
@@ -370,11 +375,11 @@ int __init oprofile_arch_init(struct oprofile_operations *ops) 
		goto out;



	for_each_possible_cpu(cpu) {

		perf_events[cpu] = kcalloc(perf_num_counters,

		perf_events[cpu] = kcalloc(num_counters,

				sizeof(struct perf_event *), GFP_KERNEL);

		if (!perf_events[cpu]) {

			pr_info("oprofile: failed to allocate %d perf events "

					"for cpu %d\n", perf_num_counters, cpu);

					"for cpu %d\n", num_counters, cpu);

			ret = -ENOMEM;

			goto out;

		}
@@ -409,7 +414,7 @@ void __exit oprofile_arch_exit(void) 
	struct perf_event *event;



	for_each_possible_cpu(cpu) {

		for (id = 0; id < perf_num_counters; ++id) {

		for (id = 0; id < num_counters; ++id) {

			event = perf_events[cpu][id];

			if (event)

				perf_event_release_kernel(event);

arch/sh/kernel/perf_event.c

+9 −0
Original line number Diff line number Diff line
@@ -59,6 +59,15 @@ static inline int sh_pmu_initialized(void) 
	return !!sh_pmu;

}



int perf_num_counters(void)

{

	if (!sh_pmu)

		return 0;



	return sh_pmu->num_events;

}

EXPORT_SYMBOL_GPL(perf_num_counters);



/*

 * Release the PMU if this is the last perf_event.

 */

include/linux/perf_event.h

+1 −0
Original line number Diff line number Diff line
@@ -849,6 +849,7 @@ extern int perf_max_events; 


extern const struct pmu *hw_perf_event_init(struct perf_event *event);



extern int perf_num_counters(void);

extern void perf_event_task_sched_in(struct task_struct *task);

extern void perf_event_task_sched_out(struct task_struct *task, struct task_struct *next);

extern void perf_event_task_tick(struct task_struct *task);

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