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Powerpc/perf: Wire up PMI throttling 

Commit 14c63f17b1 ("perf: Drop sample rate when sampling is too
slow") introduced a way to throttle PMU interrupts if we're spending
too much time just processing those. Wire up powerpc PMI handler to
use this infrastructure.

We have throttling of the *rate* of interrupts, but this adds
throttling based on the *time taken* to process the interrupts.

Signed-off-by: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
hifive-unleashed-5.1
Ravi Bangoria 2018-11-21 09:26:37 +05:30 committed by Michael Ellerman
parent c20577014f
commit 0c9108b083
1 changed files with 10 additions and 1 deletions
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11
arch/powerpc/perf/core-book3s.c
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@ -10,6 +10,7 @@
*/
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/sched/clock.h>
#include <linux/perf_event.h>
#include <linux/percpu.h>
#include <linux/hardirq.h>
@ -2166,7 +2167,7 @@ static bool pmc_overflow(unsigned long val)
/*
* Performance monitor interrupt stuff
*/
static void perf_event_interrupt(struct pt_regs *regs)
static void __perf_event_interrupt(struct pt_regs *regs)
{
int i, j;
struct cpu_hw_events *cpuhw = this_cpu_ptr(&cpu_hw_events);
@ -2250,6 +2251,14 @@ static void perf_event_interrupt(struct pt_regs *regs)
irq_exit();
}
static void perf_event_interrupt(struct pt_regs *regs)
{
u64 start_clock = sched_clock();
__perf_event_interrupt(regs);
perf_sample_event_took(sched_clock() - start_clock);
}
static int power_pmu_prepare_cpu(unsigned int cpu)
{
struct cpu_hw_events *cpuhw = &per_cpu(cpu_hw_events, cpu);