+ /*
+ * Eviction will normally happen from the packet path, and not
+ * from this gc worker.
+ *
+ * This worker is only here to reap expired entries when system went
+ * idle after a busy period.
+ *
+ * The heuristics below are supposed to balance conflicting goals:
+ *
+ * 1. Minimize time until we notice a stale entry
+ * 2. Maximize scan intervals to not waste cycles
+ *
+ * Normally, expired_count will be 0, this increases the next_run time
+ * to priorize 2) above.
+ *
+ * As soon as a timed-out entry is found, move towards 1) and increase
+ * the scan frequency.
+ * In case we have lots of evictions next scan is done immediately.
+ */