What is packet recirculation and what do the packet recirculation counters stand for in ovs-appctl dpif-netdev/pmd-stats-show?

Issue

What is packet recirculation and what do the packet recirculation counters stand for in ovs-appctl dpif-netdev/pmd-stats-show?

ovs-appctl_dpif-netdev/pmd-stats-show
(...)
pmd thread numa_id 0 core_id 2:
    packets received: 1372340779961
    packet recirculations: 1372340779912
    avg. datapath passes per packet: 2.00
    emc hits: 1224087880594
    smc hits: 0
    megaflow hits: 1520402526317
    avg. subtable lookups per megaflow hit: 1.52
    miss with success upcall: 191152888
    miss with failed upcall: 72
    avg. packets per output batch: 2.60
    idle cycles: 31692366187780014 (90.40%)
    processing cycles: 3365341446689704 (9.60%)
    avg cycles per packet: 25545.92 (35057707634469718/1372340779961)
    avg processing cycles per packet: 2452.26 (3365341446689704/1372340779961)
(...)