BUG: workqueue lockup - pool cpus=1 node=0 flags=0x0 nice=0 stuck for 55s! BUG: workqueue lockup - pool cpus=1 node=0 flags=0x0 nice=-20 stuck for 50s! Showing busy workqueues and worker pools: workqueue events: flags=0x0 pwq 2: cpus=1 node=0 flags=0x0 nice=0 active=5/256 pending: defense_work_handler, defense_work_handler, defense_work_handler, defense_work_handler, defense_work_handler workqueue events_power_efficient: flags=0x80 pwq 2: cpus=1 node=0 flags=0x0 nice=0 active=1/256 pending: check_lifetime workqueue kblockd: flags=0x18 pwq 3: cpus=1 node=0 flags=0x0 nice=-20 active=1/256 pending: blk_mq_requeue_work workqueue vmstat: flags=0xc pwq 2: cpus=1 node=0 flags=0x0 nice=0 active=1/256 pending: vmstat_update workqueue dm_bufio_cache: flags=0x8 pwq 2: cpus=1 node=0 flags=0x0 nice=0 active=1/256 pending: work_fn