rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P3780/1:b..l (detected by 1, t=10502 jiffies, g=7609, q=83 ncpus=2) task:syz.4.21 state:R running task stack:24824 pid:3780 ppid:3639 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5241 [inline] __schedule+0x143f/0x4570 kernel/sched/core.c:6558 preempt_schedule_irq+0xf7/0x1c0 kernel/sched/core.c:6870 irqentry_exit+0x53/0x80 kernel/entry/common.c:439 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:653 RIP: 0010:arch_atomic_read arch/x86/include/asm/atomic.h:29 [inline] RIP: 0010:atomic_read include/linux/atomic/atomic-instrumented.h:28 [inline] RIP: 0010:blk_cgroup_congested+0x10b/0x220 block/blk-cgroup.c:1999 Code: 74 08 48 89 ef e8 55 f1 bc fd 48 8b 5d 00 4c 01 e3 48 89 df be 04 00 00 00 e8 d1 f2 bc fd 48 89 d8 48 c1 e8 03 42 0f b6 04 38 <84> c0 75 3c 8b 1b 31 ff 89 de e8 66 78 65 fd 85 db 75 4c 48 81 c5 RSP: 0018:ffffc9000454f638 EFLAGS: 00000a06 RAX: 0000000000000000 RBX: ffff88807ebec9c8 RCX: ffffffff84252b7f RDX: 0000000000000000 RSI: 0000000000000004 RDI: ffff88807ebec9c8 RBP: ffffffff9213bd60 R08: dffffc0000000000 R09: ffffed100fd7d93a R10: 0000000000000000 R11: dffffc0000000001 R12: 00000000000009b8 R13: ffffc9000454f778 R14: ffffffff84252a99 R15: dffffc0000000000 __cgroup_throttle_swaprate+0x6d/0x1b0 mm/swapfile.c:3671 cgroup_throttle_swaprate include/linux/swap.h:662 [inline] folio_throttle_swaprate include/linux/swap.h:671 [inline] shmem_add_to_page_cache+0xb90/0x1e60 mm/shmem.c:717 shmem_get_folio_gfp+0x164e/0x3470 mm/shmem.c:1971 shmem_get_folio mm/shmem.c:2072 [inline] shmem_write_begin+0x16e/0x4e0 mm/shmem.c:2559 generic_perform_write+0x2fc/0x5e0 mm/filemap.c:3817 __generic_file_write_iter+0x176/0x400 mm/filemap.c:3945 generic_file_write_iter+0xab/0x310 mm/filemap.c:3977 call_write_iter include/linux/fs.h:2265 [inline] new_sync_write fs/read_write.c:491 [inline] vfs_write+0x857/0xbc0 fs/read_write.c:584 ksys_write+0x19c/0x2c0 fs/read_write.c:637 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f74355764df RSP: 002b:00007f743639adf0 EFLAGS: 00000293 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000000002000000 RCX: 00007f74355764df RDX: 0000000002000000 RSI: 00007f742b3f7000 RDI: 0000000000000008 RBP: 0000000000000000 R08: 0000000000000000 R09: 000000000000b920 R10: 0000000000000002 R11: 0000000000000293 R12: 0000000000000008 R13: 00007f743639aef0 R14: 00007f743639aeb0 R15: 00007f742b3f7000 rcu: rcu_preempt kthread starved for 10543 jiffies! g7609 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:26712 pid:16 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5241 [inline] __schedule+0x143f/0x4570 kernel/sched/core.c:6558 schedule+0xbf/0x180 kernel/sched/core.c:6634 schedule_timeout+0x1b9/0x300 kernel/time/timer.c:1965 rcu_gp_fqs_loop+0x2d2/0x1150 kernel/rcu/tree.c:1706 rcu_gp_kthread+0xa3/0x3b0 kernel/rcu/tree.c:1905 kthread+0x28d/0x320 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 rcu: Stack dump where RCU GP kthread last ran: Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 3803 Comm: syz.3.32 Not tainted 6.1.103-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/27/2024 RIP: 0010:__sanitizer_cov_trace_switch+0x4/0xe0 kernel/kcov.c:317 Code: 49 ff c2 4c 89 12 48 c7 44 11 08 07 00 00 00 48 89 7c 11 10 48 89 74 11 18 4c 89 44 11 20 c3 0f 1f 80 00 00 00 00 41 57 41 56 <41> 54 53 48 8b 46 08 48 83 c0 f8 48 c1 c0 3d 48 83 f8 07 0f 87 ac RSP: 0018:ffffc900045df8a0 EFLAGS: 00000046 RAX: 0000000000000000 RBX: 0000000000000003 RCX: ffff888026e10000 RDX: 0000000000000000 RSI: ffffffff8d34b7c0 RDI: 0000000000000003 RBP: 00000029bbf6c0a7 R08: ffffffff817ce722 R09: ffff888079f880b8 R10: 0000000000000000 R11: dffffc0000000001 R12: ffff8880b98271c0 R13: dffffc0000000000 R14: 0000000000000001 R15: ffff8880b982a540 FS: 0000555555ecf500(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000002006b000 CR3: 0000000019b97000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: clockevents_program_event+0x7c/0x310 kernel/time/clockevents.c:315 hrtimer_start_range_ns+0xab8/0xc50 kernel/time/hrtimer.c:1300 posixtimer_rearm+0x1ad/0x3f0 kernel/time/posix-timers.c:323 dequeue_signal+0x245/0x590 kernel/signal.c:703 get_signal+0x5f2/0x17d0 kernel/signal.c:2750 arch_do_signal_or_restart+0xb0/0x1a10 arch/x86/kernel/signal.c:871 exit_to_user_mode_loop+0x6a/0x100 kernel/entry/common.c:174 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:210 __syscall_exit_to_user_mode_work kernel/entry/common.c:292 [inline] syscall_exit_to_user_mode+0x60/0x270 kernel/entry/common.c:303 do_syscall_64+0x47/0xb0 arch/x86/entry/common.c:87 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f807765648a Code: 1e 01 45 31 ff 45 31 e4 89 44 24 18 48 8b 7c 24 08 44 89 fa 4d 8b 4d 30 4c 89 e0 48 8d 14 d7 4e 03 0c 32 80 3d fe 15 2b 00 00 <4d> 89 cc 4c 89 ca 74 28 25 ff 0f 00 00 83 f0 3d 8d 04 c0 89 c2 c1 RSP: 002b:00007ffc84cc05a0 EFLAGS: 00000202 RAX: ffffffff8a9f8523 RBX: 00007f8078435720 RCX: ffffffff8a9f8a60 RDX: 00007f8076bff3e8 RSI: ffffffff8a9f8a60 RDI: 00007f8076bfd000 RBP: 0000000000000000 R08: 00007f80778f0000 R09: ffffffff8a9f6730 R10: 000000008a9f8a64 R11: 0000000000000011 R12: ffffffff8a9f8523 R13: 00007f80779060f0 R14: 0000000000000008 R15: 000000000000047d