BUG: workqueue lockup - pool cpus=0 node=0 flags=0x0 nice=0 stuck for 46s!
Showing busy workqueues and worker pools:
workqueue events: flags=0x0
  pwq 2: cpus=1 node=0 flags=0x0 nice=0 active=4/256 refcnt=5
    pending: psi_avgs_work, ovs_dp_masks_rebalance, ovs_dp_masks_rebalance, ovs_dp_masks_rebalance
  pwq 0: cpus=0 node=0 flags=0x0 nice=0 active=12/256 refcnt=13
    pending: free_work, vmstat_shepherd, hci_cmd_timeout, hci_cmd_timeout, hci_cmd_timeout, hci_cmd_timeout, hci_cmd_timeout, hci_cmd_timeout, ovs_dp_masks_rebalance, ovs_dp_masks_rebalance, ovs_dp_masks_rebalance, ovs_dp_masks_rebalance
workqueue events_long: flags=0x0
  pwq 2: cpus=1 node=0 flags=0x0 nice=0 active=4/256 refcnt=5
    pending: defense_work_handler, defense_work_handler, defense_work_handler, defense_work_handler
  pwq 0: cpus=0 node=0 flags=0x0 nice=0 active=3/256 refcnt=4
    pending: defense_work_handler, defense_work_handler, defense_work_handler
workqueue events_unbound: flags=0x2
  pwq 4: cpus=0-1 flags=0x4 nice=0 active=1/512 refcnt=3
    pending: flush_memcg_stats_dwork
workqueue events_power_efficient: flags=0x82
  pwq 4: cpus=0-1 flags=0x4 nice=0 active=5/256 refcnt=7
    in-flight: 439:gc_worker
    pending: do_cache_clean, fb_flashcursor, neigh_periodic_work, neigh_periodic_work
workqueue mm_percpu_wq: flags=0x8
  pwq 2: cpus=1 node=0 flags=0x0 nice=0 active=1/256 refcnt=2
    pending: vmstat_update
  pwq 0: cpus=0 node=0 flags=0x0 nice=0 active=1/256 refcnt=2
    pending: vmstat_update
workqueue writeback: flags=0x4a
  pwq 4: cpus=0-1 flags=0x4 nice=0 active=1/256 refcnt=3
    pending: wb_workfn
workqueue kblockd: flags=0x18
  pwq 3: cpus=1 node=0 flags=0x0 nice=-20 active=1/256 refcnt=2
    pending: blk_mq_timeout_work
workqueue dm_bufio_cache: flags=0x8
  pwq 2: cpus=1 node=0 flags=0x0 nice=0 active=1/256 refcnt=2
    pending: work_fn
workqueue krxrpcd: flags=0x0
  pwq 0: cpus=0 node=0 flags=0x0 nice=0 active=1/1 refcnt=5
    pending: rxrpc_peer_keepalive_worker
    inactive: rxrpc_peer_keepalive_worker, rxrpc_peer_keepalive_worker, rxrpc_peer_keepalive_worker
pool 4: cpus=0-1 flags=0x4 nice=0 hung=25s workers=7 idle: 4033 293 409 148 136 9