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: Matt Fleming <matt@console-pimps.org>
Tested-by: Will Deacon <will.deacon@arm.com>
Acked-by: Paul Mundt <lethal@linux-sh.org>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Robert Richter <robert.richter@amd.com>
diff --git a/arch/arm/kernel/perf_event.c b/arch/arm/kernel/perf_event.c
index 417c392..3b0aedf 100644
--- a/arch/arm/kernel/perf_event.c
+++ b/arch/arm/kernel/perf_event.c
@@ -123,6 +123,12 @@
}
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) \
diff --git a/arch/arm/oprofile/common.c b/arch/arm/oprofile/common.c
index d660cb8..1e971a7 100644
--- a/arch/arm/oprofile/common.c
+++ b/arch/arm/oprofile/common.c
@@ -43,7 +43,7 @@
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 @@
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 @@
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 @@
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 @@
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 @@
{
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 @@
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 @@
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 @@
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);
diff --git a/arch/sh/kernel/perf_event.c b/arch/sh/kernel/perf_event.c
index 7a3dc35..2cb9ad5 100644
--- a/arch/sh/kernel/perf_event.c
+++ b/arch/sh/kernel/perf_event.c
@@ -59,6 +59,15 @@
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.
*/
diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h
index 716f99b..1a02192 100644
--- a/include/linux/perf_event.h
+++ b/include/linux/perf_event.h
@@ -849,6 +849,7 @@
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);