hrtimer: interrupt took 6731213 ns rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: (detected by 1, t=16762 jiffies, g=9593, q=459) rcu: All QSes seen, last rcu_preempt kthread activity 15495 (4294962574-4294947079), jiffies_till_next_fqs=1, root ->qsmask 0x0 rcu: rcu_preempt kthread starved for 15495 jiffies! g9593 f0x2 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=1 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:28800 pid: 14 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:4339 [inline] __schedule+0x916/0x23e0 kernel/sched/core.c:5147 schedule+0xcf/0x270 kernel/sched/core.c:5226 schedule_timeout+0x14a/0x250 kernel/time/timer.c:1892 rcu_gp_fqs_loop kernel/rcu/tree.c:2004 [inline] rcu_gp_kthread+0xd07/0x2300 kernel/rcu/tree.c:2177 kthread+0x3b1/0x4a0 kernel/kthread.c:313 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 1 CPU: 1 PID: 25 Comm: kworker/u4:1 Not tainted 5.13.0-rc6-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/29/2022 Workqueue: writeback wb_workfn (flush-8:0) Call Trace: __dump_stack lib/dump_stack.c:79 [inline] dump_stack+0x141/0x1d7 lib/dump_stack.c:120 nmi_cpu_backtrace.cold+0x44/0xd7 lib/nmi_backtrace.c:105 nmi_trigger_cpumask_backtrace+0x1b3/0x230 lib/nmi_backtrace.c:62 trigger_single_cpu_backtrace include/linux/nmi.h:164 [inline] rcu_check_gp_kthread_starvation.cold+0x1cc/0x1d1 kernel/rcu/tree_stall.h:480 print_other_cpu_stall kernel/rcu/tree_stall.h:585 [inline] check_cpu_stall kernel/rcu/tree_stall.h:710 [inline] rcu_pending kernel/rcu/tree.c:3911 [inline] rcu_sched_clock_irq+0x2079/0x20e0 kernel/rcu/tree.c:2649 update_process_times+0x16d/0x200 kernel/time/timer.c:1796 tick_sched_handle+0x9b/0x180 kernel/time/tick-sched.c:226 tick_sched_timer+0x1b0/0x2d0 kernel/time/tick-sched.c:1374 __run_hrtimer kernel/time/hrtimer.c:1583 [inline] __hrtimer_run_queues+0x1c0/0xe40 kernel/time/hrtimer.c:1647 hrtimer_interrupt+0x330/0xa00 kernel/time/hrtimer.c:1709 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1089 [inline] __sysvec_apic_timer_interrupt+0x146/0x540 arch/x86/kernel/apic/apic.c:1106 sysvec_apic_timer_interrupt+0x8e/0xc0 arch/x86/kernel/apic/apic.c:1100 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:647 RIP: 0010:csd_lock_wait kernel/smp.c:440 [inline] RIP: 0010:smp_call_function_many_cond+0x452/0xc20 kernel/smp.c:967 Code: 0b 00 85 ed 74 4d 48 b8 00 00 00 00 00 fc ff df 4d 89 f4 4c 89 f5 49 c1 ec 03 83 e5 07 49 01 c4 83 c5 03 e8 e0 39 0b 00 f3 90 <41> 0f b6 04 24 40 38 c5 7c 08 84 c0 0f 85 33 06 00 00 8b 43 08 31 RSP: 0018:ffffc90000dfef48 EFLAGS: 00000293 RAX: 0000000000000000 RBX: ffff8880b9c3bee0 RCX: 0000000000000000 RDX: ffff8880157c1c40 RSI: ffffffff8169a180 RDI: 0000000000000003 RBP: 0000000000000003 R08: 0000000000000000 R09: 0000000000000000 R10: ffffffff8169a1a6 R11: 0000000000000000 R12: ffffed10173877dd R13: 0000000000000000 R14: ffff8880b9c3bee8 R15: 0000000000000001 on_each_cpu_cond_mask+0x56/0xa0 kernel/smp.c:1133 __flush_tlb_multi arch/x86/include/asm/paravirt.h:87 [inline] flush_tlb_multi arch/x86/mm/tlb.c:862 [inline] flush_tlb_mm_range+0x1d8/0x230 arch/x86/mm/tlb.c:948 flush_tlb_page arch/x86/include/asm/tlbflush.h:239 [inline] ptep_clear_flush+0x12b/0x160 mm/pgtable-generic.c:97 page_mkclean_one+0x4d1/0xa80 mm/rmap.c:934 rmap_walk_file+0x397/0x860 mm/rmap.c:1951 rmap_walk+0x105/0x190 mm/rmap.c:1969 page_mkclean+0x21c/0x2b0 mm/rmap.c:1002 clear_page_dirty_for_io+0x31c/0xa10 mm/page-writeback.c:2698 mpage_submit_page+0x80/0x2a0 fs/ext4/inode.c:2080 mpage_map_and_submit_buffers fs/ext4/inode.c:2348 [inline] mpage_map_and_submit_extent fs/ext4/inode.c:2487 [inline] ext4_writepages+0x24c1/0x3b70 fs/ext4/inode.c:2800 do_writepages+0xec/0x290 mm/page-writeback.c:2352 __writeback_single_inode+0x126/0xfd0 fs/fs-writeback.c:1467 writeback_sb_inodes+0x53d/0xef0 fs/fs-writeback.c:1732 __writeback_inodes_wb+0xc6/0x280 fs/fs-writeback.c:1801 wb_writeback+0x814/0xc40 fs/fs-writeback.c:1907 wb_check_old_data_flush fs/fs-writeback.c:2009 [inline] wb_do_writeback fs/fs-writeback.c:2062 [inline] wb_workfn+0x891/0x12d0 fs/fs-writeback.c:2091 process_one_work+0x98d/0x1600 kernel/workqueue.c:2276 worker_thread+0x64c/0x1120 kernel/workqueue.c:2422 kthread+0x3b1/0x4a0 kernel/kthread.c:313 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294