sched: DL replenish lagged too much rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P5730/1:b..l P5606/1:b..l rcu: (detected by 0, t=10502 jiffies, g=142165, q=235 ncpus=1) task:syz-executor state:R running task stack:22696 pid:5606 tgid:5606 ppid:5604 task_flags:0x400140 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5510 [inline] __schedule+0x125c/0x6730 kernel/sched/core.c:7234 preempt_schedule_irq+0x50/0x90 kernel/sched/core.c:7556 irqentry_exit_to_kernel_mode_preempt include/linux/irq-entry-common.h:468 [inline] irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:539 [inline] irqentry_exit+0x205/0xa00 kernel/entry/common.c:167 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674 RIP: 0010:__sanitizer_cov_trace_pc+0x0/0x70 kernel/kcov.c:210 Code: f6 f2 5e 00 48 89 df 5b e9 1d 6e 64 00 be 03 00 00 00 5b e9 42 32 13 03 66 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1e fa 65 8b 05 05 1e 5a 12 48 8b 34 24 65 48 8b 15 e1 1d 5a RSP: 0018:ffffc90004407660 EFLAGS: 00000293 RAX: 0000000000000000 RBX: ffffea0000fb1c40 RCX: ffffffff8249ccfb RDX: 0000000000000000 RSI: 0000000000000002 RDI: ffff88807ee4a540 RBP: ffffea0000fb1c74 R08: 0000000000000007 R09: 0000000000000002 R10: 0000000000000000 R11: 0000000000000000 R12: ffffea0000fb1c40 R13: ffff88802c36c2c0 R14: 0000000000000000 R15: dffffc0000000000 find_get_entry mm/filemap.c:2096 [inline] find_lock_entries+0x31a/0x1190 mm/filemap.c:2183 shmem_undo_range+0x212/0x1570 mm/shmem.c:1141 shmem_truncate_range mm/shmem.c:1287 [inline] shmem_evict_inode+0x3a5/0xbe0 mm/shmem.c:1417 evict+0x3c2/0xad0 fs/inode.c:825 iput_final fs/inode.c:2019 [inline] iput.part.0+0x989/0x1050 fs/inode.c:2068 iput+0x35/0x40 fs/inode.c:2034 filename_unlinkat+0x466/0x730 fs/namei.c:5589 __do_sys_unlink fs/namei.c:5620 [inline] __se_sys_unlink fs/namei.c:5617 [inline] __x64_sys_unlink+0x46/0x70 fs/namei.c:5617 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x115/0x870 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f672ed9d107 RSP: 002b:00007fff5d797a28 EFLAGS: 00000206 ORIG_RAX: 0000000000000057 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f672ed9d107 RDX: 00007fff5d797a50 RSI: 00007fff5d797ae0 RDI: 00007fff5d797ae0 RBP: 00007fff5d797ae0 R08: 00007fff5d798ae0 R09: 00000000ffffffff R10: 0000000000000100 R11: 0000000000000206 R12: 00007fff5d798b70 R13: 00007f672ee3445c R14: 000000000013fc8d R15: 00007fff5d798bb0 task:kworker/0:6 state:R running task stack:23576 pid:5730 tgid:5730 ppid:2 task_flags:0x4208060 flags:0x00080000 Workqueue: events_power_efficient gc_worker Call Trace: context_switch kernel/sched/core.c:5510 [inline] __schedule+0x125c/0x6730 kernel/sched/core.c:7234 preempt_schedule_irq+0x50/0x90 kernel/sched/core.c:7556 irqentry_exit_to_kernel_mode_preempt include/linux/irq-entry-common.h:468 [inline] irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:539 [inline] irqentry_exit+0x205/0xa00 kernel/entry/common.c:167 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674 RIP: 0010:lock_acquire+0x5e/0x370 kernel/locking/lockdep.c:5872 Code: 05 fb 8c 7e 12 83 f8 07 0f 87 da 00 00 00 48 0f a3 05 86 93 3c 0f 0f 82 ac 02 00 00 8b 35 4e c7 3c 0f 85 f6 0f 85 c7 00 00 00 <48> 8b 44 24 30 65 48 2b 05 9d 8c 7e 12 0f 85 ec 02 00 00 48 83 c4 RSP: 0018:ffffc900050bfad0 EFLAGS: 00000206 RAX: 0000000000000046 RBX: 0000000000000000 RCX: 0000000000000000 RDX: 0000000000000000 RSI: ffffffff8e18229c RDI: ffffffff8c402680 RBP: ffffffff8ebe8200 R08: 00000000ac9a4ebc R09: 0000000000000007 R10: 0000000000000200 R11: 0000000000000000 R12: 0000000000000002 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 rcu_lock_acquire include/linux/rcupdate.h:300 [inline] rcu_read_lock include/linux/rcupdate.h:840 [inline] gc_worker+0x22b/0x1a10 net/netfilter/nf_conntrack_core.c:1532 process_one_work+0xa23/0x1940 kernel/workqueue.c:3322 process_scheduled_works kernel/workqueue.c:3405 [inline] worker_thread+0x5ef/0xe50 kernel/workqueue.c:3486 kthread+0x370/0x450 kernel/kthread.c:436 ret_from_fork+0x72b/0xd50 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 rcu: rcu_preempt kthread starved for 5609 jiffies! g142165 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:27848 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5510 [inline] __schedule+0x125c/0x6730 kernel/sched/core.c:7234 __schedule_loop kernel/sched/core.c:7311 [inline] schedule+0xdd/0x2c0 kernel/sched/core.c:7326 schedule_timeout+0x127/0x280 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x1a9/0x900 kernel/rcu/tree.c:2123 rcu_gp_kthread+0x179/0x230 kernel/rcu/tree.c:2325 kthread+0x370/0x450 kernel/kthread.c:436 ret_from_fork+0x72b/0xd50 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 rcu: Stack dump where RCU GP kthread last ran: CPU: 0 UID: 0 PID: 3224 Comm: kworker/R-bat_e Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/16/2026 Workqueue: bat_events batadv_dat_purge RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:179 [inline] RIP: 0010:_raw_spin_unlock_irqrestore+0x31/0x80 kernel/locking/spinlock.c:198 Code: f5 53 48 8b 74 24 10 48 89 fb 48 83 c7 18 e8 b6 cf 27 f6 48 89 df e8 3e 1f 28 f6 f7 c5 00 02 00 00 75 23 9c 58 f6 c4 02 75 37 01 00 00 00 e8 05 2e 17 f6 65 8b 05 4e 57 a6 08 85 c0 74 16 5b RSP: 0018:ffffc90000007c68 EFLAGS: 00000246 RAX: 0000000000000006 RBX: ffff88801df08000 RCX: 0000000000000004 RDX: 0000000000000000 RSI: ffffffff8e1a815f RDI: ffffffff8c402680 RBP: 0000000000000246 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000000 R12: ffff888194f17710 R13: ffff888194f17708 R14: ffff88802bab74a3 R15: ffff88802bab7410 FS: 0000000000000000(0000) GS:ffff888123dd8000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055a2ba7cdbe0 CR3: 000000005bb88000 CR4: 00000000003526f0 Call Trace: spin_unlock_irqrestore include/linux/spinlock.h:408 [inline] dummy_timer+0x1d91/0x36f0 drivers/usb/gadget/udc/dummy_hcd.c:2036 __run_hrtimer kernel/time/hrtimer.c:2032 [inline] __hrtimer_run_queues+0x462/0x9c0 kernel/time/hrtimer.c:2096 hrtimer_run_softirq+0x17d/0x2c0 kernel/time/hrtimer.c:2113 handle_softirqs+0x1ea/0x9b0 kernel/softirq.c:622 do_softirq kernel/softirq.c:523 [inline] do_softirq+0xac/0xe0 kernel/softirq.c:510 __local_bh_enable_ip+0xf8/0x120 kernel/softirq.c:450 spin_unlock_bh include/linux/spinlock.h:396 [inline] __batadv_dat_purge.part.0+0x294/0x3c0 net/batman-adv/distributed-arp-table.c:186 __batadv_dat_purge net/batman-adv/distributed-arp-table.c:167 [inline] batadv_dat_purge+0x4b/0xa0 net/batman-adv/distributed-arp-table.c:205 process_one_work+0xa23/0x1940 kernel/workqueue.c:3322 process_scheduled_works kernel/workqueue.c:3405 [inline] rescuer_thread+0x905/0x14a0 kernel/workqueue.c:3629 kthread+0x370/0x450 kernel/kthread.c:436 ret_from_fork+0x72b/0xd50 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245