Commit 14c63f17b1fde ("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.bango...@linux.ibm.com> --- v1: https://lkml.org/lkml/2018/11/14/627 arch/powerpc/perf/core-book3s.c | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-) diff --git a/arch/powerpc/perf/core-book3s.c b/arch/powerpc/perf/core-book3s.c index 81f8a0c838ae..3cd2ec9c9732 100644 --- a/arch/powerpc/perf/core-book3s.c +++ b/arch/powerpc/perf/core-book3s.c @@ -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> @@ -2148,7 +2149,7 @@ 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); @@ -2232,6 +2233,14 @@ 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); -- 2.17.1