rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: (detected by 0, t=10502 jiffies, g=144473, q=4) rcu: All QSes seen, last rcu_preempt kthread activity 10502 (4295050676-4295040174), jiffies_till_next_fqs=1, root ->qsmask 0x0 syz-executor.5 R running task 26768 10327 8176 0x00000000 Call Trace: sched_show_task kernel/sched/core.c:5338 [inline] sched_show_task.cold+0x2e2/0x343 kernel/sched/core.c:5313 print_other_cpu_stall kernel/rcu/tree.c:1430 [inline] check_cpu_stall kernel/rcu/tree.c:1557 [inline] __rcu_pending kernel/rcu/tree.c:3293 [inline] rcu_pending kernel/rcu/tree.c:3336 [inline] rcu_check_callbacks.cold+0xaf0/0xddc kernel/rcu/tree.c:2682 update_process_times+0x2a/0x70 kernel/time/timer.c:1638 tick_sched_handle+0x9b/0x180 kernel/time/tick-sched.c:168 tick_sched_timer+0x42/0x130 kernel/time/tick-sched.c:1278 __run_hrtimer kernel/time/hrtimer.c:1401 [inline] __hrtimer_run_queues+0x2fc/0xd50 kernel/time/hrtimer.c:1463 hrtimer_interrupt+0x312/0x770 kernel/time/hrtimer.c:1521 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1067 [inline] smp_apic_timer_interrupt+0x10c/0x550 arch/x86/kernel/apic/apic.c:1092 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:893 RIP: 0010:vcpu_enter_guest+0xed3/0x5ed0 arch/x86/kvm/x86.c:7831 Code: ff df 48 c1 e8 03 80 3c 10 00 0f 85 cb 44 00 00 48 83 3d 67 2f a6 07 00 0f 84 c0 36 00 00 e8 94 7b 5b 00 fb 66 0f 1f 44 00 00 01 00 00 00 e8 13 73 3a 00 65 8b 1d 7c c6 f5 7e 31 ff 89 de e8 RSP: 0018:ffff8880494bfa30 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13 RAX: 0000000000040000 RBX: ffff8880a3f44400 RCX: ffffc900108eb000 RDX: 0000000000040000 RSI: ffffffff810c273c RDI: ffff8880a3f44c7c RBP: ffff8880494bfb40 R08: ffff8880a3f44400 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: ffff888048098ac0 R13: ffff888048098aec R14: fffffdd564b95918 R15: 0000000000000000 vcpu_run arch/x86/kvm/x86.c:7913 [inline] kvm_arch_vcpu_ioctl_run+0x446/0x16a0 arch/x86/kvm/x86.c:8113 kvm_vcpu_ioctl+0x493/0xe20 arch/x86/kvm/../../../virt/kvm/kvm_main.c:2667 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:501 [inline] do_vfs_ioctl+0xcda/0x12e0 fs/ioctl.c:688 ksys_ioctl+0x9b/0xc0 fs/ioctl.c:705 __do_sys_ioctl fs/ioctl.c:712 [inline] __se_sys_ioctl fs/ioctl.c:710 [inline] __x64_sys_ioctl+0x6f/0xb0 fs/ioctl.c:710 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x45c4a9 Code: ad b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 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 0f 83 7b b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f0934e15c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f0934e166d4 RCX: 000000000045c4a9 RDX: 0000000000000000 RSI: 000000000000ae80 RDI: 0000000000000007 RBP: 000000000076bf20 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000000003bf R14: 00000000004c60e4 R15: 000000000076bf2c rcu: rcu_preempt kthread starved for 10502 jiffies! g144473 f0x2 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=1 rcu: RCU grace-period kthread stack dump: rcu_preempt R running task 29136 10 2 0x80000000 Call Trace: schedule+0x8d/0x1b0 kernel/sched/core.c:3559 schedule_timeout+0x4d1/0xf20 kernel/time/timer.c:1806 rcu_gp_kthread+0xcee/0x2060 kernel/rcu/tree.c:2202 kthread+0x34a/0x420 kernel/kthread.c:246 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415 rcu: INFO: rcu_sched detected stalls on CPUs/tasks: rcu: (detected by 0, t=10549 jiffies, g=6213, q=1) rcu: All QSes seen, last rcu_sched kthread activity 10549 (4295050724-4295040175), jiffies_till_next_fqs=1, root ->qsmask 0x0 syz-executor.5 R running task 26768 10327 8176 0x80000000 Call Trace: sched_show_task kernel/sched/core.c:5338 [inline] sched_show_task.cold+0x2e2/0x343 kernel/sched/core.c:5313 print_other_cpu_stall kernel/rcu/tree.c:1430 [inline] check_cpu_stall kernel/rcu/tree.c:1557 [inline] __rcu_pending kernel/rcu/tree.c:3293 [inline] rcu_pending kernel/rcu/tree.c:3336 [inline] rcu_check_callbacks.cold+0xaf0/0xddc kernel/rcu/tree.c:2682 update_process_times+0x2a/0x70 kernel/time/timer.c:1638 tick_sched_handle+0x9b/0x180 kernel/time/tick-sched.c:168 tick_sched_timer+0x42/0x130 kernel/time/tick-sched.c:1278 __run_hrtimer kernel/time/hrtimer.c:1401 [inline] __hrtimer_run_queues+0x2fc/0xd50 kernel/time/hrtimer.c:1463 hrtimer_interrupt+0x312/0x770 kernel/time/hrtimer.c:1521 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1067 [inline] smp_apic_timer_interrupt+0x10c/0x550 arch/x86/kernel/apic/apic.c:1092 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:893 RIP: 0010:vcpu_enter_guest+0xed3/0x5ed0 arch/x86/kvm/x86.c:7831 Code: ff df 48 c1 e8 03 80 3c 10 00 0f 85 cb 44 00 00 48 83 3d 67 2f a6 07 00 0f 84 c0 36 00 00 e8 94 7b 5b 00 fb 66 0f 1f 44 00 00 01 00 00 00 e8 13 73 3a 00 65 8b 1d 7c c6 f5 7e 31 ff 89 de e8 RSP: 0018:ffff8880494bfa30 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13 RAX: 0000000000040000 RBX: ffff8880a3f44400 RCX: ffffc900108eb000 RDX: 0000000000040000 RSI: ffffffff810c273c RDI: ffff8880a3f44c7c RBP: ffff8880494bfb40 R08: ffff8880a3f44400 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: ffff888048098ac0 R13: ffff888048098aec R14: fffffdd564b95918 R15: 0000000000000000 vcpu_run arch/x86/kvm/x86.c:7913 [inline] kvm_arch_vcpu_ioctl_run+0x446/0x16a0 arch/x86/kvm/x86.c:8113 kvm_vcpu_ioctl+0x493/0xe20 arch/x86/kvm/../../../virt/kvm/kvm_main.c:2667 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:501 [inline] do_vfs_ioctl+0xcda/0x12e0 fs/ioctl.c:688 ksys_ioctl+0x9b/0xc0 fs/ioctl.c:705 __do_sys_ioctl fs/ioctl.c:712 [inline] __se_sys_ioctl fs/ioctl.c:710 [inline] __x64_sys_ioctl+0x6f/0xb0 fs/ioctl.c:710 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x45c4a9 Code: ad b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 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 0f 83 7b b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f0934e15c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f0934e166d4 RCX: 000000000045c4a9 RDX: 0000000000000000 RSI: 000000000000ae80 RDI: 0000000000000007 RBP: 000000000076bf20 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000000003bf R14: 00000000004c60e4 R15: 000000000076bf2c rcu: rcu_sched kthread starved for 10549 jiffies! g6213 f0x2 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=1 rcu: RCU grace-period kthread stack dump: rcu_sched R running task 29136 11 2 0x80000000 Call Trace: schedule+0x8d/0x1b0 kernel/sched/core.c:3559 schedule_timeout+0x4d1/0xf20 kernel/time/timer.c:1806 rcu_gp_kthread+0xcee/0x2060 kernel/rcu/tree.c:2202 kthread+0x34a/0x420 kernel/kthread.c:246 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415 sched: RT throttling activated