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Perf: Restore correct CPU's PMU counters after power collpase

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Since the L1CC PMU's are per CPU, the variable to detect if a CPU
came out of powercollapse also needs to be a per CPU variable. This
ensures that we reset and restore the correct CPU's PMU counters.

Change-Id: I02273df2eff9f6d88d68f46a7752c107b290a8ef
Signed-off-by: Ashwin Chaugule <ashwinc@codeaurora.org>
This commit is contained in:
Ashwin Chaugule
2012-09-06 17:49:31 -04:00
committed by Iliyan Malchev
parent 36fdfc2a9a
commit 2e62e8bde4
2 changed files with 7 additions and 5 deletions
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1
arch/arm/include/asm/pmu.h
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@@ -113,7 +113,6 @@ struct arm_pmu {
struct mutex reserve_mutex;
u64 max_period;
struct platform_device *plat_device;
u32 from_idle;
irqreturn_t (*handle_irq)(int irq_num, void *dev);
int (*request_pmu_irq)(int irq, irq_handler_t *irq_h);
void (*free_pmu_irq)(int irq);

11
arch/arm/kernel/perf_event.c
View File

@@ -41,6 +41,7 @@
*/
#define ARMPMU_MAX_HWEVENTS 32
static DEFINE_PER_CPU(u32, from_idle);
static DEFINE_PER_CPU(struct perf_event * [ARMPMU_MAX_HWEVENTS], hw_events);
static DEFINE_PER_CPU(unsigned long [BITS_TO_LONGS(ARMPMU_MAX_HWEVENTS)], used_mask);
static DEFINE_PER_CPU(struct pmu_hw_events, cpu_hw_events);
@@ -602,7 +603,7 @@ static void armpmu_enable(struct pmu *pmu)
int enabled = bitmap_weight(hw_events->used_mask, armpmu->num_events);
int idx;
if (armpmu->from_idle) {
if (__get_cpu_var(from_idle)) {
for (idx = 0; idx <= cpu_pmu->num_events; ++idx) {
struct perf_event *event = hw_events->events[idx];
@@ -613,9 +614,12 @@ static void armpmu_enable(struct pmu *pmu)
}
/* Reset bit so we don't needlessly re-enable counters.*/
armpmu->from_idle = 0;
__get_cpu_var(from_idle) = 0;
}
/* So we don't start the PMU before enabling counters after idle. */
barrier();
if (enabled)
armpmu->start();
}
@@ -731,7 +735,6 @@ static void __init cpu_pmu_init(struct arm_pmu *armpmu)
* UNKNOWN at reset, the PMU must be explicitly reset to avoid reading
* junk values out of them.
*/
static int __cpuinit pmu_cpu_notify(struct notifier_block *b,
unsigned long action, void *hcpu)
{
@@ -805,7 +808,7 @@ static int perf_cpu_pm_notifier(struct notifier_block *self, unsigned long cmd,
* Flip this bit so armpmu_enable knows it needs
* to re-enable active counters.
*/
cpu_pmu->from_idle = 1;
__get_cpu_var(from_idle) = 1;
cpu_pmu->reset(NULL);
perf_pmu_enable(&cpu_pmu->pmu);
}