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): P5346/1:b..l P23549/1:b..l rcu: (detected by 1, t=10502 jiffies, g=143269, q=421800 ncpus=2) task:syz.4.5085 state:R running task stack:25848 pid:23549 tgid:23548 ppid:13314 task_flags:0x40054c flags:0x00080001 Call Trace: context_switch kernel/sched/core.c:5387 [inline] __schedule+0x10e9/0x6820 kernel/sched/core.c:7188 preempt_schedule_irq+0x50/0x90 kernel/sched/core.c:7512 irqentry_exit_to_kernel_mode_preempt include/linux/irq-entry-common.h:476 [inline] irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:547 [inline] irqentry_exit+0x1fe/0x790 kernel/entry/common.c:164 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:lock_is_held_type+0xf5/0x140 kernel/locking/lockdep.c:5945 Code: ff ff ff ff 65 0f c1 15 f1 e5 80 08 83 fa 01 8b 44 24 04 75 2d 9c 5a 80 e6 02 75 47 41 f7 c5 00 02 00 00 74 01 fb 48 83 c4 08 <5b> 5d 41 5c 41 5d 41 5e 41 5f c3 cc cc cc cc e9 57 39 03 00 31 c0 RSP: 0018:ffffc900054c71b0 EFLAGS: 00000292 RAX: 0000000000000000 RBX: ffff888035ec1590 RCX: 0000000000000001 RDX: 0000000000000046 RSI: ffffffff8defa991 RDI: ffffffff8c1c3600 RBP: ffff888041a5ca00 R08: 0000000000000005 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000000 R12: 00000000ffffffff R13: 0000000000000246 R14: ffff888041a5d5b8 R15: 0000000000000001 lock_is_held include/linux/lockdep.h:249 [inline] xa_entry include/linux/xarray.h:1226 [inline] xas_find+0x3d7/0x8e0 lib/xarray.c:1423 find_get_entry mm/filemap.c:2068 [inline] find_lock_entries+0x176/0x1190 mm/filemap.c:2172 shmem_undo_range+0x212/0x1570 mm/shmem.c:1131 shmem_truncate_range mm/shmem.c:1277 [inline] shmem_evict_inode+0x3f3/0xc40 mm/shmem.c:1407 evict+0x3c2/0xad0 fs/inode.c:841 iput_final fs/inode.c:1960 [inline] iput.part.0+0x605/0xf50 fs/inode.c:2009 iput+0x35/0x40 fs/inode.c:1975 dentry_unlink_inode+0x2c0/0x4c0 fs/dcache.c:476 __dentry_kill+0x1d0/0x690 fs/dcache.c:718 finish_dput+0x76/0x480 fs/dcache.c:927 dput.part.0+0x456/0x570 fs/dcache.c:976 dput+0x1f/0x30 fs/dcache.c:968 __fput+0x519/0xb50 fs/file_table.c:518 task_work_run+0x150/0x240 kernel/task_work.c:233 exit_task_work include/linux/task_work.h:40 [inline] do_exit+0x8d2/0x2a60 kernel/exit.c:975 do_group_exit+0xd5/0x2a0 kernel/exit.c:1117 get_signal+0x1ec7/0x21e0 kernel/signal.c:3037 arch_do_signal_or_restart+0x91/0x7a0 arch/x86/kernel/signal.c:337 __exit_to_user_mode_loop kernel/entry/common.c:64 [inline] exit_to_user_mode_loop+0x86/0x4a0 kernel/entry/common.c:98 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:238 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:318 [inline] do_syscall_64+0x706/0xf80 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f753539cdd9 RSP: 002b:00007f753631f0e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: 0000000000000000 RBX: 00007f7535615fa8 RCX: 00007f753539cdd9 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f7535615fa8 RBP: 00007f7535615fa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f7535616038 R14: 00007ffcf1970c40 R15: 00007ffcf1970d28 task:crond state:R running task stack:25112 pid:5346 tgid:5346 ppid:1 task_flags:0x400000 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5387 [inline] __schedule+0x10e9/0x6820 kernel/sched/core.c:7188 preempt_schedule_irq+0x50/0x90 kernel/sched/core.c:7512 irqentry_exit_to_kernel_mode_preempt include/linux/irq-entry-common.h:476 [inline] irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:547 [inline] irqentry_exit+0x1fe/0x790 kernel/entry/common.c:164 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:lock_acquire+0x5e/0x370 kernel/locking/lockdep.c:5872 Code: 05 7b 2f 26 12 83 f8 07 0f 87 d9 02 00 00 48 0f a3 05 86 2a f3 0e 0f 82 a4 02 00 00 8b 35 0e 5e f3 0e 85 f6 0f 85 bf 00 00 00 <48> 8b 44 24 30 65 48 2b 05 1d 2f 26 12 0f 85 ed 02 00 00 48 83 c4 RSP: 0018:ffffc900026c7538 EFLAGS: 00000206 RAX: 0000000000000046 RBX: 0000000000000000 RCX: 0000000000000001 RDX: 0000000000000000 RSI: ffffffff8defa991 RDI: ffffffff8c1c3600 RBP: ffffffff8e7e54e0 R08: 00000000811c6616 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:838 [inline] class_rcu_constructor include/linux/rcupdate.h:1181 [inline] unwind_next_frame+0xd1/0x2090 arch/x86/kernel/unwind_orc.c:495 __unwind_start+0x3d1/0x7f0 arch/x86/kernel/unwind_orc.c:787 unwind_start arch/x86/include/asm/unwind.h:64 [inline] arch_stack_walk+0x73/0xf0 arch/x86/kernel/stacktrace.c:24 stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122 save_stack+0x162/0x1e0 mm/page_owner.c:165 __reset_page_owner+0x84/0x190 mm/page_owner.c:320 reset_page_owner include/linux/page_owner.h:25 [inline] __free_pages_prepare mm/page_alloc.c:1402 [inline] __free_frozen_pages+0x747/0x1040 mm/page_alloc.c:2943 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x47/0xf0 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x1a0/0x1f0 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x69/0x90 mm/kasan/common.c:350 kasan_slab_alloc include/linux/kasan.h:253 [inline] slab_post_alloc_hook mm/slub.c:4569 [inline] slab_alloc_node mm/slub.c:4898 [inline] kmem_cache_alloc_noprof+0x241/0x6e0 mm/slub.c:4905 alloc_empty_file+0x5b/0x1c0 fs/file_table.c:262 path_openat+0xe8/0x31a0 fs/namei.c:4844 do_file_open+0x20e/0x430 fs/namei.c:4887 do_sys_openat2+0x10d/0x1e0 fs/open.c:1364 do_sys_open fs/open.c:1370 [inline] __do_sys_openat fs/open.c:1386 [inline] __se_sys_openat fs/open.c:1381 [inline] __x64_sys_openat+0x12d/0x210 fs/open.c:1381 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x10b/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f50a4788407 RSP: 002b:00007ffcd8975730 EFLAGS: 00000202 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007f50a4638c80 RCX: 00007f50a4788407 RDX: 0000000000000000 RSI: 00007f50a497b764 RDI: ffffffffffffff9c RBP: 0000000000000008 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 00007f50a4987492 R13: 00007f50a4987492 R14: 0000000000000001 R15: 0000000000000024 rcu: rcu_preempt kthread starved for 10588 jiffies! g143269 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:27080 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5387 [inline] __schedule+0x10e9/0x6820 kernel/sched/core.c:7188 __schedule_loop kernel/sched/core.c:7267 [inline] schedule+0xdd/0x390 kernel/sched/core.c:7282 schedule_timeout+0x127/0x280 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x1a9/0x900 kernel/rcu/tree.c:2095 rcu_gp_kthread+0x179/0x230 kernel/rcu/tree.c:2297 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: 1 UID: 0 PID: 0 Comm: swapper/1 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:63 Code: 46 93 02 e9 c3 42 03 00 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d a3 80 21 00 fb f4 cc cc cc cc 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90 RSP: 0018:ffffc90000197df0 EFLAGS: 00000246 RAX: 0000000008a9ada9 RBX: ffff88801e2ba500 RCX: ffffffff8b8a1045 RDX: 0000000000000000 RSI: ffffffff8df1fea8 RDI: ffffffff8c1c3600 RBP: 0000000000000000 R08: 0000000000000001 R09: ffffed10170a67b5 R10: ffff8880b8533dab R11: 0000000000000000 R12: 0000000000000001 R13: ffffed1003c574a0 R14: 0000000000000001 R15: ffffffff90d79b50 FS: 0000000000000000(0000) GS:ffff888124476000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000200000016000 CR3: 0000000028991000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600 Call Trace: arch_safe_halt arch/x86/include/asm/paravirt.h:62 [inline] default_idle+0x9/0x10 arch/x86/kernel/process.c:767 default_idle_call+0x6c/0xb0 kernel/sched/idle.c:122 cpuidle_idle_call kernel/sched/idle.c:199 [inline] do_idle+0x464/0x590 kernel/sched/idle.c:352 cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:451 start_secondary+0x21d/0x2d0 arch/x86/kernel/smpboot.c:312 common_startup_64+0x13e/0x148