rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 1-....: (10499 ticks this GP) idle=50a/1/0x4000000000000000 softirq=232210/232210 fqs=37 (t=10501 jiffies g=411617 q=138) rcu: rcu_preempt kthread starved for 937 jiffies! g411617 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:28912 pid: 10 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:3778 [inline] __schedule+0x9b9/0xd20 kernel/sched/core.c:4527 NMI backtrace for cpu 1 CPU: 1 PID: 25589 Comm: syz-executor.3 Not tainted 5.9.0-rc3-syzkaller #0 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+0x1d6/0x29e lib/dump_stack.c:118 nmi_cpu_backtrace+0x9f/0x180 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x16a/0x280 lib/nmi_backtrace.c:62 trigger_single_cpu_backtrace include/linux/nmi.h:164 [inline] rcu_dump_cpu_stacks+0x199/0x2a0 kernel/rcu/tree_stall.h:318 print_cpu_stall kernel/rcu/tree_stall.h:551 [inline] check_cpu_stall kernel/rcu/tree_stall.h:625 [inline] rcu_pending kernel/rcu/tree.c:3637 [inline] rcu_sched_clock_irq+0x1920/0x1eb0 kernel/rcu/tree.c:2519 update_process_times+0x130/0x1b0 kernel/time/timer.c:1710 tick_sched_handle kernel/time/tick-sched.c:176 [inline] tick_sched_timer+0x25e/0x410 kernel/time/tick-sched.c:1328 __run_hrtimer kernel/time/hrtimer.c:1524 [inline] __hrtimer_run_queues+0x42d/0x930 kernel/time/hrtimer.c:1588 hrtimer_interrupt+0x373/0xd60 kernel/time/hrtimer.c:1650 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1080 [inline] __sysvec_apic_timer_interrupt+0xf0/0x260 arch/x86/kernel/apic/apic.c:1097 run_on_irqstack_cond arch/x86/include/asm/irq_stack.h:50 [inline] sysvec_apic_timer_interrupt+0xd0/0xf0 arch/x86/kernel/apic/apic.c:1091 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:581 RIP: 0010:qdisc_root_sleeping include/net/sch_generic.h:520 [inline] RIP: 0010:pie_timer+0x49/0x170 net/sched/sch_pie.c:427 Code: 48 89 d8 48 c1 e8 03 42 80 3c 28 00 74 08 48 89 df e8 4b c7 10 fb 4c 8b 23 49 8d 5c 24 40 48 89 d8 48 c1 e8 03 42 80 3c 28 00 <74> 08 48 89 df e8 2d c7 10 fb 49 83 c7 88 48 8b 1b 48 83 c3 10 48 RSP: 0018:ffffc90000da8d80 EFLAGS: 00000246 RAX: 1ffff11008ef0b08 RBX: ffff888047785840 RCX: ffff8882002ac4c0 RDX: 0000000000000101 RSI: 0000000000000000 RDI: ffff888047785b38 RBP: ffffc90000da8f10 R08: ffffffff816522d8 R09: fffffbfff131e2e6 R10: fffffbfff131e2e6 R11: 0000000000000000 R12: ffff888047785800 R13: dffffc0000000000 R14: ffffffff86a3fa90 R15: ffff888047785b38 call_timer_fn+0x91/0x160 kernel/time/timer.c:1413 expire_timers kernel/time/timer.c:1458 [inline] __run_timers+0x65e/0x830 kernel/time/timer.c:1755 run_timer_softirq+0x46/0x80 kernel/time/timer.c:1768 __do_softirq+0x256/0x6d5 kernel/softirq.c:298 asm_call_on_stack+0xf/0x20 arch/x86/entry/entry_64.S:706 __run_on_irqstack arch/x86/include/asm/irq_stack.h:22 [inline] run_on_irqstack_cond arch/x86/include/asm/irq_stack.h:48 [inline] do_softirq_own_stack+0x91/0xe0 arch/x86/kernel/irq_64.c:77 invoke_softirq kernel/softirq.c:393 [inline] __irq_exit_rcu+0x21f/0x230 kernel/softirq.c:423 irq_exit_rcu+0x5/0x20 kernel/softirq.c:435 sysvec_apic_timer_interrupt+0xd5/0xf0 arch/x86/kernel/apic/apic.c:1091 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:581 RIP: 0010:arch_local_irq_restore arch/x86/include/asm/paravirt.h:770 [inline] RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:160 [inline] RIP: 0010:_raw_spin_unlock_irqrestore+0x63/0x90 kernel/locking/spinlock.c:191 Code: b9 00 00 00 00 00 fc ff df 80 3c 08 00 74 0c 48 c7 c7 b8 17 4d 89 e8 ac a4 86 f9 48 83 3d 4c fa 1e 01 00 74 2a 4c 89 f7 57 9d <0f> 1f 44 00 00 bf 01 00 00 00 e8 7e b5 22 f9 65 8b 05 83 e0 d3 77 RSP: 0018:ffffc90006a1ee88 EFLAGS: 00000286 RAX: 1ffffffff129a2f7 RBX: ffffffff894ff500 RCX: dffffc0000000000 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000286 RBP: ffff8882002ac840 R08: dffffc0000000000 R09: fffffbfff167d899 R10: fffffbfff167d899 R11: 0000000000000000 R12: ffffffff894ff5d8 R13: 1ffffffff129fe00 R14: 0000000000000286 R15: ffffffff894ff500 rcu_preempt_deferred_qs_irqrestore+0x6a6/0x9b0 kernel/rcu/tree.c:2174 rcu_read_unlock_special kernel/rcu/tree_plugin.h:633 [inline] __rcu_read_unlock+0x3bf/0x460 kernel/rcu/tree_plugin.h:395 rcu_read_unlock include/linux/rcupdate.h:687 [inline] list_lru_count_one+0x25a/0x2a0 mm/list_lru.c:184 list_lru_shrink_count include/linux/list_lru.h:123 [inline] super_cache_count+0x134/0x290 fs/super.c:147 do_shrink_slab+0xc1/0x5c0 mm/vmscan.c:431 shrink_slab+0x188/0x2b0 mm/vmscan.c:674 shrink_node_memcgs+0x392/0x710 mm/vmscan.c:2653 shrink_node+0xd70/0x1b10 mm/vmscan.c:2768 shrink_zones+0x27c/0x8d0 mm/vmscan.c:2971 do_try_to_free_pages+0x216/0xa70 mm/vmscan.c:3026 try_to_free_pages+0x318/0xb30 mm/vmscan.c:3265 __perform_reclaim mm/page_alloc.c:4260 [inline] __alloc_pages_direct_reclaim mm/page_alloc.c:4281 [inline] __alloc_pages_slowpath+0xee9/0x2290 mm/page_alloc.c:4685 __alloc_pages_nodemask+0x3b8/0x5c0 mm/page_alloc.c:4901 alloc_pages_vma+0x4dd/0xd10 mm/mempolicy.c:2238 shmem_alloc_page mm/shmem.c:1563 [inline] shmem_alloc_and_acct_page+0x40e/0xbe0 mm/shmem.c:1588 shmem_getpage_gfp+0x2031/0x2c50 mm/shmem.c:1884 shmem_getpage mm/shmem.c:155 [inline] shmem_write_begin+0xcd/0x1a0 mm/shmem.c:2521 generic_perform_write+0x23b/0x4e0 mm/filemap.c:3403 __generic_file_write_iter+0x22b/0x4e0 mm/filemap.c:3532 generic_file_write_iter+0x4a6/0x650 mm/filemap.c:3564 call_write_iter include/linux/fs.h:1882 [inline] new_sync_write fs/read_write.c:503 [inline] vfs_write+0xa96/0xd10 fs/read_write.c:578 ksys_pwrite64 fs/read_write.c:685 [inline] __do_sys_pwrite64 fs/read_write.c:695 [inline] __se_sys_pwrite64 fs/read_write.c:692 [inline] __x64_sys_pwrite64+0x151/0x1c0 fs/read_write.c:692 do_syscall_64+0x31/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x417167 Code: 12 00 00 00 0f 05 48 3d 01 f0 ff ff 0f 83 a1 18 00 00 c3 48 83 ec 08 e8 a7 f9 ff ff 48 89 04 24 49 89 ca b8 12 00 00 00 0f 05 <48> 8b 3c 24 48 89 c2 e8 ed f9 ff ff 48 89 d0 48 83 c4 08 48 3d 01 RSP: 002b:00007f4917ad4a20 EFLAGS: 00000293 ORIG_RAX: 0000000000000012 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000417167 RDX: 0000000000000026 RSI: 0000000020000100 RDI: 0000000000000005 RBP: 0000000000000000 R08: 0000000020002718 R09: 0000000000000000 R10: 0000000000000003 R11: 0000000000000293 R12: 0000000000000009 R13: 0000000000000005 R14: 0000000000000005 R15: 0000000020002650