rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 0-...!: (10500 ticks this GP) idle=1a74/1/0x4000000000000000 softirq=7901/7901 fqs=0 (t=10500 jiffies g=7625 q=3882 ncpus=2) rcu: rcu_preempt kthread starved for 10500 jiffies! g7625 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->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:R running task stack:29320 pid:17 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5178 [inline] __schedule+0xadf/0x5270 kernel/sched/core.c:6490 schedule+0xda/0x1b0 kernel/sched/core.c:6566 schedule_timeout+0x14a/0x2a0 kernel/time/timer.c:1935 rcu_gp_fqs_loop+0x190/0x910 kernel/rcu/tree.c:1658 rcu_gp_kthread+0x236/0x360 kernel/rcu/tree.c:1857 kthread+0x2e4/0x3a0 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306 rcu: Stack dump where RCU GP kthread last ran: CPU: 0 PID: 16 Comm: ksoftirqd/0 Not tainted 6.0.0-syzkaller-09589-g55be6084c8e0-dirty #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/22/2022 RIP: 0010:write_comp_data+0x7/0x90 kernel/kcov.c:223 Code: ff 00 75 10 65 48 8b 04 25 80 6f 02 00 48 8b 80 b0 15 00 00 c3 66 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 65 8b 05 89 29 87 7e <49> 89 f1 89 c6 49 89 d2 81 e6 00 01 00 00 49 89 f8 65 48 8b 14 25 RSP: 0018:ffffc90000157b30 EFLAGS: 00000246 RAX: 0000000000000101 RBX: ffff888066e69060 RCX: ffffffff878c48ee RDX: 0000000000000000 RSI: 0019999999999998 RDI: 0000000000000007 RBP: 0000000225c17d04 R08: 0000000000000005 R09: 0000000000000000 R10: 0000000000000000 R11: 00000000b1b78399 R12: 00000015798ee228 R13: ffff8880690a7b00 R14: 0000000000000000 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8880b9a00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f801f5b0000 CR3: 0000000020ffc000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: pie_calculate_probability+0x1ee/0x7c0 net/sched/sch_pie.c:340 fq_pie_timer+0x1b3/0x360 net/sched/sch_fq_pie.c:382 call_timer_fn+0x1a0/0x6b0 kernel/time/timer.c:1474 expire_timers kernel/time/timer.c:1519 [inline] __run_timers.part.0+0x674/0xa80 kernel/time/timer.c:1790 __run_timers kernel/time/timer.c:1768 [inline] run_timer_softirq+0xb3/0x1d0 kernel/time/timer.c:1803 __do_softirq+0x1d0/0x9c8 kernel/softirq.c:571 run_ksoftirqd kernel/softirq.c:934 [inline] run_ksoftirqd+0x2d/0x60 kernel/softirq.c:926 smpboot_thread_fn+0x645/0x9c0 kernel/smpboot.c:164 kthread+0x2e4/0x3a0 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306 CPU: 0 PID: 16 Comm: ksoftirqd/0 Not tainted 6.0.0-syzkaller-09589-g55be6084c8e0-dirty #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/22/2022 RIP: 0010:write_comp_data+0x7/0x90 kernel/kcov.c:223 Code: ff 00 75 10 65 48 8b 04 25 80 6f 02 00 48 8b 80 b0 15 00 00 c3 66 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 65 8b 05 89 29 87 7e <49> 89 f1 89 c6 49 89 d2 81 e6 00 01 00 00 49 89 f8 65 48 8b 14 25 RSP: 0018:ffffc90000157b30 EFLAGS: 00000246 RAX: 0000000000000101 RBX: ffff888066e69060 RCX: ffffffff878c48ee RDX: 0000000000000000 RSI: 0019999999999998 RDI: 0000000000000007 RBP: 0000000225c17d04 R08: 0000000000000005 R09: 0000000000000000 R10: 0000000000000000 R11: 00000000b1b78399 R12: 00000015798ee228 R13: ffff8880690a7b00 R14: 0000000000000000 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8880b9a00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f801f5b0000 CR3: 0000000020ffc000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: pie_calculate_probability+0x1ee/0x7c0 net/sched/sch_pie.c:340 fq_pie_timer+0x1b3/0x360 net/sched/sch_fq_pie.c:382 call_timer_fn+0x1a0/0x6b0 kernel/time/timer.c:1474 expire_timers kernel/time/timer.c:1519 [inline] __run_timers.part.0+0x674/0xa80 kernel/time/timer.c:1790 __run_timers kernel/time/timer.c:1768 [inline] run_timer_softirq+0xb3/0x1d0 kernel/time/timer.c:1803 __do_softirq+0x1d0/0x9c8 kernel/softirq.c:571 run_ksoftirqd kernel/softirq.c:934 [inline] run_ksoftirqd+0x2d/0x60 kernel/softirq.c:926 smpboot_thread_fn+0x645/0x9c0 kernel/smpboot.c:164 kthread+0x2e4/0x3a0 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306 ------------[ cut here ]------------ WARNING: CPU: 0 PID: 16 at net/sched/sch_fq_pie.c:390 fq_pie_timer+0x2ba/0x360 net/sched/sch_fq_pie.c:390 Modules linked in: CPU: 0 PID: 16 Comm: ksoftirqd/0 Not tainted 6.0.0-syzkaller-09589-g55be6084c8e0-dirty #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/22/2022 RIP: 0010:fq_pie_timer+0x2ba/0x360 net/sched/sch_fq_pie.c:390 Code: 48 c1 ea 03 80 3c 02 00 0f 85 a9 00 00 00 48 8b 35 eb 5f 34 04 48 89 ef 48 01 de e8 e0 70 de f9 e9 62 ff ff ff e8 16 b8 ee f9 <0f> 0b eb a9 48 89 cf e8 0a 1f 3c fa e9 3d fe ff ff e8 00 1f 3c fa RSP: 0018:ffffc90000157bb8 EFLAGS: 00010246 RAX: 0000000000000000 RBX: ffffffffffffffb7 RCX: 0000000000000100 RDX: ffff888011a7d880 RSI: ffffffff878c922a RDI: 0000000000000007 RBP: ffff8880690a7b50 R08: 0000000000000007 R09: 0000000000000000 R10: ffffffffffffffb7 R11: 00000000b1b78399 R12: dffffc0000000000 R13: 0000000000000007 R14: 0000000000000400 R15: ffff8880690a7b00 FS: 0000000000000000(0000) GS:ffff8880b9a00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f801f5b0000 CR3: 000000000bc8e000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: call_timer_fn+0x1a0/0x6b0 kernel/time/timer.c:1474 expire_timers kernel/time/timer.c:1519 [inline] __run_timers.part.0+0x674/0xa80 kernel/time/timer.c:1790 __run_timers kernel/time/timer.c:1768 [inline] run_timer_softirq+0xb3/0x1d0 kernel/time/timer.c:1803 __do_softirq+0x1d0/0x9c8 kernel/softirq.c:571 run_ksoftirqd kernel/softirq.c:934 [inline] run_ksoftirqd+0x2d/0x60 kernel/softirq.c:926 smpboot_thread_fn+0x645/0x9c0 kernel/smpboot.c:164 kthread+0x2e4/0x3a0 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306