bisecting fixing commit since ae4b064e2a616b545acf02b8f50cc513b32c7522
building syzkaller on 08003f6440deafc4e193b159c4acece64f7864b1
testing commit ae4b064e2a616b545acf02b8f50cc513b32c7522 with gcc (GCC) 8.4.1 20210217
kernel signature: 79450ac766e6ee1c6d674c4246108ce8e17a02768744d4e7b53c5a30c04b9f53
run #0: crashed: BUG: workqueue lockup
run #1: crashed: BUG: workqueue lockup
run #2: crashed: BUG: workqueue lockup
run #3: crashed: INFO: rcu detected stall in chrdev_open
run #4: crashed: INFO: rcu detected stall in chrdev_open
run #5: crashed: INFO: rcu detected stall in corrupted
run #6: crashed: BUG: workqueue lockup
run #7: crashed: INFO: rcu detected stall in corrupted
run #8: crashed: INFO: rcu detected stall in corrupted
run #9: crashed: BUG: workqueue lockup
run #10: crashed: INFO: rcu detected stall in chrdev_open
run #11: crashed: INFO: rcu detected stall in chrdev_open
run #12: crashed: INFO: rcu detected stall in chrdev_open
run #13: crashed: BUG: workqueue lockup
run #14: crashed: INFO: rcu detected stall in corrupted
run #15: crashed: INFO: rcu detected stall in chrdev_open
run #16: crashed: INFO: rcu detected stall in chrdev_open
run #17: crashed: INFO: rcu detected stall in corrupted
run #18: crashed: no output from test machine
run #19: crashed: INFO: rcu detected stall in corrupted
testing current HEAD 6905b1dc3c32a094f0da61bd656a740f0a97d592
testing commit 6905b1dc3c32a094f0da61bd656a740f0a97d592 with gcc (GCC) 10.2.1 20210217
kernel signature: 16490ab2bfb4e2a24c156e25af88d013398cdd45915da113d97eb285470a6451
run #0: crashed: BUG: workqueue lockup
run #1: crashed: BUG: workqueue lockup
run #2: crashed: BUG: workqueue lockup
run #3: crashed: BUG: workqueue lockup
run #4: crashed: BUG: workqueue lockup
run #5: crashed: INFO: rcu detected stall in corrupted
run #6: crashed: INFO: rcu detected stall in chrdev_open
run #7: crashed: INFO: rcu detected stall in corrupted
run #8: crashed: INFO: rcu detected stall in chrdev_open
run #9: crashed: INFO: rcu detected stall in chrdev_open
revisions tested: 2, total time: 28m7.456799433s (build: 12m6.260235851s, test: 14m56.19129792s)
the crash still happens on HEAD
commit msg: Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm
crash: INFO: rcu detected stall in chrdev_open
rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	0-...!: (10500 ticks this GP) idle=20e/1/0x4000000000000000 softirq=8682/8682 fqs=0 
	(t=10501 jiffies g=6197 q=408)
rcu: rcu_preempt kthread timer wakeup didn't happen for 10501 jiffies! g6197 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402
rcu: 	Possible timer handling issue on cpu=0 timer-softirq=1790
rcu: rcu_preempt kthread starved for 10504 jiffies! g6197 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->cpu=0
rcu: 	Unless rcu_preempt kthread gets sufficient CPU time, OOM is now expected behavior.
rcu: RCU grace-period kthread stack dump:
task:rcu_preempt     state:I stack:28744 pid:   13 ppid:     2 flags:0x00004000
Call Trace:
 context_switch kernel/sched/core.c:4322 [inline]
 __schedule+0xf86/0x2180 kernel/sched/core.c:5073
 schedule+0xdb/0x280 kernel/sched/core.c:5152
 schedule_timeout+0x133/0x220 kernel/time/timer.c:1892
 rcu_gp_fqs_loop kernel/rcu/tree.c:2005 [inline]
 rcu_gp_kthread+0xcf6/0x2200 kernel/rcu/tree.c:2178
 kthread+0x37d/0x460 kernel/kthread.c:292
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294
rcu: Stack dump where RCU GP kthread last ran:
NMI backtrace for cpu 0
CPU: 0 PID: 6981 Comm: syz-executor.5 Not tainted 5.12.0-rc5-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:79 [inline]
 dump_stack+0x114/0x14e lib/dump_stack.c:120
 nmi_cpu_backtrace.cold+0x30/0x9c lib/nmi_backtrace.c:105
 nmi_trigger_cpumask_backtrace+0x120/0x170 lib/nmi_backtrace.c:62
 arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:39
 trigger_single_cpu_backtrace include/linux/nmi.h:164 [inline]
 rcu_check_gp_kthread_starvation+0x1a1/0x1b8 kernel/rcu/tree_stall.h:478
 print_cpu_stall kernel/rcu/tree_stall.h:620 [inline]
 check_cpu_stall kernel/rcu/tree_stall.h:697 [inline]
 rcu_pending kernel/rcu/tree.c:3830 [inline]
 rcu_sched_clock_irq.cold+0x677/0x11b6 kernel/rcu/tree.c:2650
 update_process_times+0x139/0x1b0 kernel/time/timer.c:1796
 tick_sched_handle+0x77/0x140 kernel/time/tick-sched.c:226
 tick_sched_timer+0x142/0x230 kernel/time/tick-sched.c:1369
 __run_hrtimer kernel/time/hrtimer.c:1537 [inline]
 __hrtimer_run_queues+0x1b7/0xc30 kernel/time/hrtimer.c:1601
 hrtimer_interrupt+0x2f3/0x950 kernel/time/hrtimer.c:1663
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1089 [inline]
 __sysvec_apic_timer_interrupt+0x143/0x530 arch/x86/kernel/apic/apic.c:1106
 sysvec_apic_timer_interrupt+0x98/0xc0 arch/x86/kernel/apic/apic.c:1100
 </IRQ>
 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:632
RIP: 0010:unwind_next_frame.part.0+0x123/0x750 arch/x86/kernel/unwind_frame.c:295
Code: 1d 02 00 00 49 8d 46 d8 49 39 c5 0f 84 02 03 00 00 48 8d 7b 50 48 b8 00 00 00 00 00 fc ff df 48 89 f9 48 c1 e9 03 80 3c 01 00 <0f> 85 62 04 00 00 4c 8b 73 50 4d 85 f6 0f 84 a3 02 00 00 48 c7 43
RSP: 0018:ffffc90003d97438 EFLAGS: 00000246
RAX: dffffc0000000000 RBX: ffffc90003d974a8 RCX: 1ffff920007b2e9f
RDX: ffff88810890e400 RSI: ffffffff83b8122a RDI: ffffc90003d974f8
RBP: ffffc90003d97480 R08: 1ffff920007b2e9d R09: ffffc90003d974d0
R10: ffffc90003d974e0 R11: 0000000000008400 R12: 0000000000000000
R13: ffffc90003d97868 R14: ffffc90003d97f58 R15: ffffc90003d97500
 unwind_next_frame+0x32/0x50 arch/x86/kernel/unwind_frame.c:259
 arch_stack_walk+0x7d/0xe0 arch/x86/kernel/stacktrace.c:25
 stack_trace_save+0x8f/0xc0 kernel/stacktrace.c:121
 kasan_save_stack+0x23/0x50 mm/kasan/common.c:38
 kasan_set_track mm/kasan/common.c:46 [inline]
 set_alloc_info mm/kasan/common.c:427 [inline]
 ____kasan_kmalloc mm/kasan/common.c:506 [inline]
 __kasan_kmalloc+0x7f/0xa0 mm/kasan/common.c:515
 kasan_kmalloc include/linux/kasan.h:233 [inline]
 kmem_cache_alloc_trace+0x20b/0x400 mm/slab.c:3570
 kmalloc include/linux/slab.h:554 [inline]
 tty_alloc_file drivers/tty/tty_io.c:186 [inline]
 tty_open+0x14a/0xf60 drivers/tty/tty_io.c:2145
 chrdev_open+0x237/0x6a0 fs/char_dev.c:414
 do_dentry_open+0x42d/0xf90 fs/open.c:826
 vfs_open+0x9a/0xc0 fs/open.c:940
 do_open fs/namei.c:3365 [inline]
 path_openat+0xa73/0x25d0 fs/namei.c:3498
 do_filp_open+0x17d/0x3b0 fs/namei.c:3525
 do_sys_openat2+0x120/0x3d0 fs/open.c:1187
 do_sys_open fs/open.c:1203 [inline]
 __do_sys_openat fs/open.c:1219 [inline]
 __se_sys_openat fs/open.c:1214 [inline]
 __x64_sys_openat+0x124/0x200 fs/open.c:1214
 do_syscall_64+0x32/0x80 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x462209
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f2a08f1d1a8 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 000000000052bf00 RCX: 0000000000462209
RDX: 0000000000000000 RSI: 0000000020000380 RDI: ffffffffffffff9c
RBP: 0000000000000004 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 00000000004f8a08 R14: 00000000004b41d5 R15: 00007f2a08f1d6bc
NMI backtrace for cpu 0
CPU: 0 PID: 6981 Comm: syz-executor.5 Not tainted 5.12.0-rc5-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:79 [inline]
 dump_stack+0x114/0x14e lib/dump_stack.c:120
 nmi_cpu_backtrace.cold+0x30/0x9c lib/nmi_backtrace.c:105
 nmi_trigger_cpumask_backtrace+0x120/0x170 lib/nmi_backtrace.c:62
 arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:39
 trigger_single_cpu_backtrace include/linux/nmi.h:164 [inline]
 rcu_dump_cpu_stacks+0x1cc/0x252 kernel/rcu/tree_stall.h:341
 print_cpu_stall kernel/rcu/tree_stall.h:622 [inline]
 check_cpu_stall kernel/rcu/tree_stall.h:697 [inline]
 rcu_pending kernel/rcu/tree.c:3830 [inline]
 rcu_sched_clock_irq.cold+0x67c/0x11b6 kernel/rcu/tree.c:2650
 update_process_times+0x139/0x1b0 kernel/time/timer.c:1796
 tick_sched_handle+0x77/0x140 kernel/time/tick-sched.c:226
 tick_sched_timer+0x142/0x230 kernel/time/tick-sched.c:1369
 __run_hrtimer kernel/time/hrtimer.c:1537 [inline]
 __hrtimer_run_queues+0x1b7/0xc30 kernel/time/hrtimer.c:1601
 hrtimer_interrupt+0x2f3/0x950 kernel/time/hrtimer.c:1663
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1089 [inline]
 __sysvec_apic_timer_interrupt+0x143/0x530 arch/x86/kernel/apic/apic.c:1106
 sysvec_apic_timer_interrupt+0x98/0xc0 arch/x86/kernel/apic/apic.c:1100
 </IRQ>
 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:632
RIP: 0010:unwind_next_frame.part.0+0x123/0x750 arch/x86/kernel/unwind_frame.c:295
Code: 1d 02 00 00 49 8d 46 d8 49 39 c5 0f 84 02 03 00 00 48 8d 7b 50 48 b8 00 00 00 00 00 fc ff df 48 89 f9 48 c1 e9 03 80 3c 01 00 <0f> 85 62 04 00 00 4c 8b 73 50 4d 85 f6 0f 84 a3 02 00 00 48 c7 43
RSP: 0018:ffffc90003d97438 EFLAGS: 00000246
RAX: dffffc0000000000 RBX: ffffc90003d974a8 RCX: 1ffff920007b2e9f
RDX: ffff88810890e400 RSI: ffffffff83b8122a RDI: ffffc90003d974f8
RBP: ffffc90003d97480 R08: 1ffff920007b2e9d R09: ffffc90003d974d0
R10: ffffc90003d974e0 R11: 0000000000008400 R12: 0000000000000000
R13: ffffc90003d97868 R14: ffffc90003d97f58 R15: ffffc90003d97500
 unwind_next_frame+0x32/0x50 arch/x86/kernel/unwind_frame.c:259
 arch_stack_walk+0x7d/0xe0 arch/x86/kernel/stacktrace.c:25
 stack_trace_save+0x8f/0xc0 kernel/stacktrace.c:121
 kasan_save_stack+0x23/0x50 mm/kasan/common.c:38
 kasan_set_track mm/kasan/common.c:46 [inline]
 set_alloc_info mm/kasan/common.c:427 [inline]
 ____kasan_kmalloc mm/kasan/common.c:506 [inline]
 __kasan_kmalloc+0x7f/0xa0 mm/kasan/common.c:515
 kasan_kmalloc include/linux/kasan.h:233 [inline]
 kmem_cache_alloc_trace+0x20b/0x400 mm/slab.c:3570
 kmalloc include/linux/slab.h:554 [inline]
 tty_alloc_file drivers/tty/tty_io.c:186 [inline]
 tty_open+0x14a/0xf60 drivers/tty/tty_io.c:2145
 chrdev_open+0x237/0x6a0 fs/char_dev.c:414
 do_dentry_open+0x42d/0xf90 fs/open.c:826
 vfs_open+0x9a/0xc0 fs/open.c:940
 do_open fs/namei.c:3365 [inline]
 path_openat+0xa73/0x25d0 fs/namei.c:3498
 do_filp_open+0x17d/0x3b0 fs/namei.c:3525
 do_sys_openat2+0x120/0x3d0 fs/open.c:1187
 do_sys_open fs/open.c:1203 [inline]
 __do_sys_openat fs/open.c:1219 [inline]
 __se_sys_openat fs/open.c:1214 [inline]
 __x64_sys_openat+0x124/0x200 fs/open.c:1214
 do_syscall_64+0x32/0x80 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x462209
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f2a08f1d1a8 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 000000000052bf00 RCX: 0000000000462209
RDX: 0000000000000000 RSI: 0000000020000380 RDI: ffffffffffffff9c
RBP: 0000000000000004 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 00000000004f8a08 R14: 00000000004b41d5 R15: 00007f2a08f1d6bc
sched: RT throttling activated
BUG: workqueue lockup - pool cpus=1 node=0 flags=0x0 nice=0 stuck for 198s!
Showing busy workqueues and worker pools:
workqueue events: flags=0x0
  pwq 2: cpus=1 node=0 flags=0x0 nice=0 active=14/256 refcnt=15
    in-flight: 5895:nsim_fib_event_work, 37:nsim_dev_trap_report_work, 6898:nsim_fib_event_work
    pending: nsim_dev_trap_report_work, psi_avgs_work, rht_deferred_worker, psi_avgs_work, ovs_dp_masks_rebalance, psi_avgs_work, cache_reap, 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=19/256 refcnt=20
    in-flight: 1315:nsim_fib_event_work, 6900:delayed_fput, 6887:nsim_fib_event_work nsim_fib_event_work
    pending: linkwatch_event, nsim_dev_trap_report_work, nsim_dev_trap_report_work, nsim_dev_trap_report_work, nsim_dev_trap_report_work, perf_sched_delayed, psi_avgs_work, ovs_dp_masks_rebalance, ovs_dp_masks_rebalance, psi_avgs_work, ovs_dp_masks_rebalance, psi_avgs_work, check_corruption, vmstat_shepherd, cache_reap
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_freezable: flags=0x4
  pwq 0: cpus=0 node=0 flags=0x0 nice=0 active=1/256 refcnt=2
    pending: update_balloon_stats_func
workqueue events_power_efficient: flags=0x80
  pwq 2: cpus=1 node=0 flags=0x0 nice=0 active=2/256 refcnt=3
    pending: gc_worker, neigh_periodic_work
  pwq 0: cpus=0 node=0 flags=0x0 nice=0 active=4/256 refcnt=5
    pending: fb_flashcursor, reg_check_chans_work, check_lifetime, 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 cgroup_pidlist_destroy: flags=0x0
  pwq 2: cpus=1 node=0 flags=0x0 nice=0 active=1/1 refcnt=2
    pending: cgroup_pidlist_destroy_work_fn
workqueue writeback: flags=0x4a
  pwq 4: cpus=0-1 flags=0x4 nice=0 active=1/256 refcnt=3
    in-flight: 24:wb_workfn
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 ipv6_addrconf: flags=0x40008
  pwq 2: cpus=1 node=0 flags=0x0 nice=0 active=1/1 refcnt=87
    pending: addrconf_dad_work
    delayed: addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work
, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work
  pwq 0: cpus=0 node=0 flags=0x0 nice=0 active=1/1 refcnt=62
    pending: addrconf_dad_work
    delayed: addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work
, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_verify_work
workqueue bat_events: flags=0xe000a
  pwq 4: cpus=0-1 flags=0x4 nice=0 active=1/1 refcnt=38
    in-flight: 5827:batadv_nc_worker
    delayed: batadv_nc_worker, batadv_nc_worker, batadv_nc_worker, batadv_nc_worker, batadv_nc_worker, batadv_mcast_mla_update, batadv_purge_orig, batadv_mcast_mla_update, batadv_purge_orig, batadv_purge_orig, batadv_purge_orig, batadv_tt_purge, batadv_tt_purge, batadv_tt_purge, batadv_dat_purge, batadv_bla_periodic_work, batadv_dat_purge, batadv_bla_periodic_work, batadv_dat_purge, batadv_bla_periodic_work, batadv_dat_purge, batadv_bla_periodic_work, batadv_dat_purge, batadv_bla_periodic_work, batadv_tt_purge, batadv_purge_orig, batadv_mcast_mla_update, batadv_mcast_mla_update, batadv_mcast_mla_update, batadv_mcast_mla_update, batadv_purge_orig, batadv_tt_purge, batadv_tt_purge, batadv_dat_purge, batadv_bla_periodic_work
pool 0: cpus=0 node=0 flags=0x0 nice=0 hung=192s workers=9 idle: 6873 5 3437 6907 6875 11
pool 2: cpus=1 node=0 flags=0x0 nice=0 hung=198s workers=10 idle: 6862 6905 6945 6944 2452 6946 19
pool 4: cpus=0-1 flags=0x4 nice=0 hung=192s workers=6 idle: 133 176 7 36