static bool xtensa_perf_event_set_period()

in kernel/perf_event.c [154:186]

• 29 lines of code
• 5 McCabe index (conditional complexity)

static bool xtensa_perf_event_set_period(struct perf_event *event,
					 struct hw_perf_event *hwc, int idx)
{
	bool rc = false;
	s64 left;

	if (!is_sampling_event(event)) {
		left = XTENSA_PMU_COUNTER_MAX;
	} else {
		s64 period = hwc->sample_period;

		left = local64_read(&hwc->period_left);
		if (left <= -period) {
			left = period;
			local64_set(&hwc->period_left, left);
			hwc->last_period = period;
			rc = true;
		} else if (left <= 0) {
			left += period;
			local64_set(&hwc->period_left, left);
			hwc->last_period = period;
			rc = true;
		}
		if (left > XTENSA_PMU_COUNTER_MAX)
			left = XTENSA_PMU_COUNTER_MAX;
	}

	local64_set(&hwc->prev_count, -left);
	xtensa_pmu_write_counter(idx, -left);
	perf_event_update_userpage(event);

	return rc;
}