+static __always_inline int irq_timings_interval_index(u64 interval)
+{
+ /*
+ * The PREDICTION_FACTOR increase the interval size for the
+ * array of exponential average.
+ */
+ u64 interval_us = (interval >> 10) / PREDICTION_FACTOR;
+
+ return likely(interval_us) ? ilog2(interval_us) : 0;
+}
+
+static __always_inline void __irq_timings_store(int irq, struct irqt_stat *irqs,
+ u64 interval)
+{
+ int index;
+
+ /*
+ * Get the index in the ema table for this interrupt.
+ */
+ index = irq_timings_interval_index(interval);
+
+ /*
+ * Store the index as an element of the pattern in another
+ * circular array.
+ */
+ irqs->circ_timings[irqs->count & IRQ_TIMINGS_MASK] = index;
+
+ irqs->ema_time[index] = irq_timings_ema_new(interval,
+ irqs->ema_time[index]);
+
+ irqs->count++;
+}
+