rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 0-...!: (10459 ticks this GP) idle=96a/1/0x4000000000000002 softirq=57883/57883 fqs=16 rcu: (t=10502 jiffies g=80053 q=997) rcu: rcu_preempt kthread starved for 10445 jiffies! g80053 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->cpu=1 rcu: RCU grace-period kthread stack dump: rcu_preempt I29168 10 2 0x80000000 Call Trace: context_switch kernel/sched/core.c:2877 [inline] __schedule+0x817/0x1cc0 kernel/sched/core.c:3518 schedule+0x92/0x180 kernel/sched/core.c:3562 schedule_timeout+0x4db/0xfd0 kernel/time/timer.c:1803 rcu_gp_fqs_loop kernel/rcu/tree.c:1971 [inline] rcu_gp_kthread+0x962/0x17b0 kernel/rcu/tree.c:2128 kthread+0x357/0x430 kernel/kthread.c:253 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352 NMI backtrace for cpu 0 CPU: 0 PID: 1128 Comm: syz-executor.1 Not tainted 5.0.0-rc8-next-20190301 #1 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x172/0x1f0 lib/dump_stack.c:113 nmi_cpu_backtrace.cold+0x63/0xa4 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x1be/0x236 lib/nmi_backtrace.c:62 arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:38 trigger_single_cpu_backtrace include/linux/nmi.h:164 [inline] rcu_dump_cpu_stacks+0x183/0x1cf kernel/rcu/tree.c:1223 print_cpu_stall kernel/rcu/tree.c:1360 [inline] check_cpu_stall kernel/rcu/tree.c:1434 [inline] rcu_pending kernel/rcu/tree.c:3103 [inline] rcu_sched_clock_irq.cold+0x500/0xa4a kernel/rcu/tree.c:2544 update_process_times+0x32/0x80 kernel/time/timer.c:1635 tick_sched_handle+0xa2/0x190 kernel/time/tick-sched.c:161 tick_sched_timer+0x47/0x130 kernel/time/tick-sched.c:1271 __run_hrtimer kernel/time/hrtimer.c:1389 [inline] __hrtimer_run_queues+0x33e/0xde0 kernel/time/hrtimer.c:1451 hrtimer_interrupt+0x314/0x770 kernel/time/hrtimer.c:1509 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1035 [inline] smp_apic_timer_interrupt+0x120/0x570 arch/x86/kernel/apic/apic.c:1060 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:807 RIP: 0010:write_comp_data+0x1e/0x70 kernel/kcov.c:123 Code: 48 89 34 d1 48 89 11 5d c3 0f 1f 00 65 4c 8b 04 25 00 ee 01 00 65 8b 05 30 2b 91 7e a9 00 01 1f 00 75 51 41 8b 80 e0 12 00 00 <83> f8 03 75 45 49 8b 80 e8 12 00 00 45 8b 80 e4 12 00 00 4c 8b 08 RSP: 0018:ffff888211ef6e88 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13 RAX: 0000000000000002 RBX: 0000000000000000 RCX: ffffffff81924d67 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000001 RBP: ffff888211ef6e90 R08: ffff88821461a600 R09: ffffed100b14a990 R10: ffffed100b14a98f R11: ffff888058a54c7f R12: 0000000000000001 R13: 0000000000000000 R14: dffffc0000000000 R15: 0000000000000000 shrink_node_memcg+0xb77/0x16b0 mm/vmscan.c:2644 shrink_node+0x287/0x1660 mm/vmscan.c:2796 shrink_zones mm/vmscan.c:3028 [inline] do_try_to_free_pages+0x3cb/0x11e0 mm/vmscan.c:3090 try_to_free_mem_cgroup_pages+0x2dd/0xa30 mm/vmscan.c:3393 try_charge+0x5bd/0x1790 mm/memcontrol.c:2252 mem_cgroup_try_charge+0x24d/0x5e0 mm/memcontrol.c:5937 mem_cgroup_try_charge_delay+0x1f/0xa0 mm/memcontrol.c:5952 shmem_getpage_gfp+0x69e/0x2500 mm/shmem.c:1859 shmem_fault+0x22d/0x760 mm/shmem.c:2053 __do_fault+0x116/0x4e0 mm/memory.c:3039 do_read_fault mm/memory.c:3449 [inline] do_fault mm/memory.c:3575 [inline] handle_pte_fault mm/memory.c:3806 [inline] __handle_mm_fault+0x2c6c/0x3ec0 mm/memory.c:3930 handle_mm_fault+0x43f/0xb30 mm/memory.c:3967 faultin_page mm/gup.c:538 [inline] __get_user_pages+0x7b6/0x1a40 mm/gup.c:741 populate_vma_page_range+0x20d/0x2a0 mm/gup.c:1399 __mm_populate+0x204/0x380 mm/gup.c:1447 mm_populate include/linux/mm.h:2383 [inline] vm_mmap_pgoff+0x213/0x230 mm/util.c:367 ksys_mmap_pgoff+0xf7/0x630 mm/mmap.c:1609 __do_sys_mmap arch/x86/kernel/sys_x86_64.c:100 [inline] __se_sys_mmap arch/x86/kernel/sys_x86_64.c:91 [inline] __x64_sys_mmap+0xe9/0x1b0 arch/x86/kernel/sys_x86_64.c:91 do_syscall_64+0x103/0x610 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x457e29 Code: ad b8 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 b8 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007fd322e7ac78 EFLAGS: 00000246 ORIG_RAX: 0000000000000009 RAX: ffffffffffffffda RBX: 0000000000000006 RCX: 0000000000457e29 RDX: 0000000000000002 RSI: 0000000000b36000 RDI: 0000000020000000 RBP: 000000000073bfa0 R08: ffffffffffffffff R09: 0000000000000000 R10: 0000000000008031 R11: 0000000000000246 R12: 00007fd322e7b6d4 R13: 00000000004c3b88 R14: 00000000004d6d40 R15: 00000000ffffffff