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arm: perf: fold percpu_pmu into pmu_hw_events

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Currently the percpu_pmu pointers used as percpu_irq dev_id values are
defined separately from the other per-cpu accounting data, which make
dynamically allocating the data (as will be required for systems with
heterogeneous CPUs) difficult.

This patch moves the percpu_pmu pointers into pmu_hw_events (which is
itself allocated per cpu), which will allow for easier dynamic
allocation. Both percpu and regular irqs are requested using percpu_pmu
pointers as tokens, freeing us from having to know whether an irq is
percpu within the handler, and thus avoiding a radix tree lookup on the
handler path.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Will Deacon <will.deacon@arm.com>
Reviewed-by: Stephen Boyd <sboyd@codeaurora.org>
Tested-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
This commit is contained in:
Mark Rutland 2014-05-13 19:46:10 +01:00 committed by Will Deacon
parent 1167925086
commit 5ebd920034
3 changed files with 23 additions and 11 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

6
arch/arm/include/asm/pmu.h
View File

@ -81,6 +81,12 @@ struct pmu_hw_events {
* read/modify/write sequences.
*/
raw_spinlock_t pmu_lock;
/*
* When using percpu IRQs, we need a percpu dev_id. Place it here as we
* already have to allocate this struct per cpu.
*/
struct arm_pmu *percpu_pmu;
};
struct arm_pmu {

14
arch/arm/kernel/perf_event.c
View File

@ -304,17 +304,21 @@ static irqreturn_t armpmu_dispatch_irq(int irq, void *dev)
int ret;
u64 start_clock, finish_clock;
if (irq_is_percpu(irq))
dev = *(void **)dev;
armpmu = dev;
/*
* we request the IRQ with a (possibly percpu) struct arm_pmu**, but
* the handlers expect a struct arm_pmu*. The percpu_irq framework will
* do any necessary shifting, we just need to perform the first
* dereference.
*/
armpmu = *(void **)dev;
plat_device = armpmu->plat_device;
plat = dev_get_platdata(&plat_device->dev);
start_clock = sched_clock();
if (plat && plat->handle_irq)
ret = plat->handle_irq(irq, dev, armpmu->handle_irq);
ret = plat->handle_irq(irq, armpmu, armpmu->handle_irq);
else
ret = armpmu->handle_irq(irq, dev);
ret = armpmu->handle_irq(irq, armpmu);
finish_clock = sched_clock();
perf_sample_event_took(finish_clock - start_clock);

14
arch/arm/kernel/perf_event_cpu.c
View File

@ -35,7 +35,6 @@
/* Set at runtime when we know what CPU type we are. */
static struct arm_pmu *cpu_pmu;
static DEFINE_PER_CPU(struct arm_pmu *, percpu_pmu);
static DEFINE_PER_CPU(struct pmu_hw_events, cpu_hw_events);
/*
@ -85,20 +84,21 @@ static void cpu_pmu_free_irq(struct arm_pmu *cpu_pmu)
{
int i, irq, irqs;
struct platform_device *pmu_device = cpu_pmu->plat_device;
struct pmu_hw_events __percpu *hw_events = cpu_pmu->hw_events;
irqs = min(pmu_device->num_resources, num_possible_cpus());
irq = platform_get_irq(pmu_device, 0);
if (irq >= 0 && irq_is_percpu(irq)) {
on_each_cpu(cpu_pmu_disable_percpu_irq, &irq, 1);
free_percpu_irq(irq, &percpu_pmu);
free_percpu_irq(irq, &hw_events->percpu_pmu);
} else {
for (i = 0; i < irqs; ++i) {
if (!cpumask_test_and_clear_cpu(i, &cpu_pmu->active_irqs))
continue;
irq = platform_get_irq(pmu_device, i);
if (irq >= 0)
free_irq(irq, cpu_pmu);
free_irq(irq, per_cpu_ptr(&hw_events->percpu_pmu, i));
}
}
}
@ -107,6 +107,7 @@ static int cpu_pmu_request_irq(struct arm_pmu *cpu_pmu, irq_handler_t handler)
{
int i, err, irq, irqs;
struct platform_device *pmu_device = cpu_pmu->plat_device;
struct pmu_hw_events __percpu *hw_events = cpu_pmu->hw_events;
if (!pmu_device)
return -ENODEV;
@ -119,7 +120,8 @@ static int cpu_pmu_request_irq(struct arm_pmu *cpu_pmu, irq_handler_t handler)
irq = platform_get_irq(pmu_device, 0);
if (irq >= 0 && irq_is_percpu(irq)) {
err = request_percpu_irq(irq, handler, "arm-pmu", &percpu_pmu);
err = request_percpu_irq(irq, handler, "arm-pmu",
&hw_events->percpu_pmu);
if (err) {
pr_err("unable to request IRQ%d for ARM PMU counters\n",
irq);
@ -146,7 +148,7 @@ static int cpu_pmu_request_irq(struct arm_pmu *cpu_pmu, irq_handler_t handler)
err = request_irq(irq, handler,
IRQF_NOBALANCING | IRQF_NO_THREAD, "arm-pmu",
cpu_pmu);
per_cpu_ptr(&hw_events->percpu_pmu, i));
if (err) {
pr_err("unable to request IRQ%d for ARM PMU counters\n",
irq);
@ -166,7 +168,7 @@ static void cpu_pmu_init(struct arm_pmu *cpu_pmu)
for_each_possible_cpu(cpu) {
struct pmu_hw_events *events = &per_cpu(cpu_hw_events, cpu);
raw_spin_lock_init(&events->pmu_lock);
per_cpu(percpu_pmu, cpu) = cpu_pmu;
events->percpu_pmu = cpu_pmu;
}
cpu_pmu->hw_events = &cpu_hw_events;