perf: RISC-V: throttle perf events

Call perf_sample_event_took() to report time spent in overflow
interrupts. Perf core uses these measurements to throttle
perf events properly.

Signed-off-by: Sergey Matyukevich <sergey.matyukevich@syntacore.com>
Reviewed-by: Atish Patra <atishp@rivosinc.com>
Link: https://lore.kernel.org/r/20220830155306.301714-4-geomatsi@gmail.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>

diff --git a/drivers/perf/riscv_pmu_sbi.c b/drivers/perf/riscv_pmu_sbi.c
index 1d05aff88c58421db76f06a9f6262f60038bd576..3e817935993356cab9cbbe4ddd02169b8e3feb5c 100644 (file)
--- a/drivers/perf/riscv_pmu_sbi.c
+++ b/drivers/perf/riscv_pmu_sbi.c
@@ -18,6 +18,7 @@
 #include <linux/of_irq.h>
 #include <linux/of.h>
 #include <linux/cpu_pm.h>
+#include <linux/sched/clock.h>
 
 #include <asm/sbi.h>
 #include <asm/hwcap.h>
@@ -570,6 +571,7 @@ static irqreturn_t pmu_sbi_ovf_handler(int irq, void *dev)
        unsigned long overflow;
        unsigned long overflowed_ctrs = 0;
        struct cpu_hw_events *cpu_hw_evt = dev;
+       u64 start_clock = sched_clock();
 
        if (WARN_ON_ONCE(!cpu_hw_evt))
                return IRQ_NONE;
@@ -638,7 +640,9 @@ static irqreturn_t pmu_sbi_ovf_handler(int irq, void *dev)
                        perf_event_overflow(event, &data, regs);
                }
        }
+
        pmu_sbi_start_overflow_mask(pmu, overflowed_ctrs);
+       perf_sample_event_took(sched_clock() - start_clock);
 
        return IRQ_HANDLED;
 }