sched: DL replenish lagged too much rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 1-...!: (3 ticks this GP) idle=2de4/1/0x4000000000000000 softirq=15900/15900 fqs=0 rcu: (detected by 0, t=10506 jiffies, g=11629, q=2527 ncpus=2) Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 5198 Comm: udevd Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 RIP: 0010:rcu_read_lock include/linux/rcupdate.h:868 [inline] RIP: 0010:advance_sched+0xa18/0xc90 net/sched/sch_taprio.c:990 Code: bd 46 f8 48 8d 1d 00 00 00 00 48 c7 c7 e0 d6 f3 8d 31 f6 31 d2 b9 02 00 00 00 45 31 c0 45 31 c9 53 e8 7c 06 3d f8 48 83 c4 08 f3 6d e6 01 89 c5 31 ff 89 c6 e8 08 bd 5f f8 85 ed 74 10 e8 1f RSP: 0018:ffffc90000a08c70 EFLAGS: 00000092 RAX: bbb5415a6e95b800 RBX: ffffffff89604ab8 RCX: bbb5415a6e95b800 RDX: 0000000000000001 RSI: ffffffff8d8f5ae9 RDI: ffffffff8bbf08e0 RBP: ffff88807a707150 R08: 0000000000000000 R09: ffffffff89604ab8 R10: dffffc0000000000 R11: ffffed10061c485e R12: ffff888030e24360 R13: ffff888030e24000 R14: 187cd136fd48bc9c R15: ffff88807a706c00 FS: 00007f2913140880(0000) GS:ffff888126238000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000555590e60808 CR3: 0000000079c0e000 CR4: 00000000003526f0 Call Trace: __run_hrtimer kernel/time/hrtimer.c:1777 [inline] __hrtimer_run_queues+0x52c/0xc60 kernel/time/hrtimer.c:1841 hrtimer_interrupt+0x45b/0xaa0 kernel/time/hrtimer.c:1903 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1041 [inline] __sysvec_apic_timer_interrupt+0x10b/0x410 arch/x86/kernel/apic/apic.c:1058 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1052 [inline] sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1052 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:lock_release+0x2b5/0x3e0 kernel/locking/lockdep.c:5893 Code: 51 48 c7 44 24 20 00 00 00 00 9c 8f 44 24 20 f7 44 24 20 00 02 00 00 75 56 f7 c3 00 02 00 00 74 01 fb 65 48 8b 05 eb 1a d1 10 <48> 3b 44 24 28 0f 85 8b 00 00 00 48 83 c4 30 5b 41 5c 41 5d 41 5e RSP: 0018:ffffc90003137770 EFLAGS: 00000206 RAX: bbb5415a6e95b800 RBX: 0000000000000202 RCX: bbb5415a6e95b800 RDX: 0000000000000000 RSI: ffffffff8d8f5ae9 RDI: ffffffff8bbf08e0 RBP: ffff88807ab147b0 R08: ffffc90003137cb8 R09: 0000000000000000 R10: ffffc900031378f8 R11: fffff52000626f21 R12: 0000000000000000 R13: 0000000000000000 R14: ffffffff8df3d6e0 R15: ffff88807ab13c80 rcu_lock_release include/linux/rcupdate.h:341 [inline] rcu_read_unlock include/linux/rcupdate.h:897 [inline] class_rcu_destructor include/linux/rcupdate.h:1195 [inline] unwind_next_frame+0x19a9/0x2390 arch/x86/kernel/unwind_orc.c:680 arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:56 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:77 unpoison_slab_object mm/kasan/common.c:342 [inline] __kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:368 kasan_slab_alloc include/linux/kasan.h:252 [inline] slab_post_alloc_hook mm/slub.c:4978 [inline] slab_alloc_node mm/slub.c:5288 [inline] kmem_cache_alloc_noprof+0x367/0x6e0 mm/slub.c:5295 getname_flags+0xb8/0x540 fs/namei.c:146 getname include/linux/fs.h:2924 [inline] getname_maybe_null include/linux/fs.h:2931 [inline] vfs_fstatat+0x43/0x170 fs/stat.c:370 __do_sys_newfstatat fs/stat.c:542 [inline] __se_sys_newfstatat fs/stat.c:536 [inline] __x64_sys_newfstatat+0x116/0x190 fs/stat.c:536 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f2912b11b0a Code: 48 8b 15 f1 f2 0d 00 f7 d8 64 89 02 b8 ff ff ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 41 89 ca b8 06 01 00 00 0f 05 <3d> 00 f0 ff ff 77 07 31 c0 c3 0f 1f 40 00 48 8b 15 b9 f2 0d 00 f7 RSP: 002b:00007ffef532ba48 EFLAGS: 00000246 ORIG_RAX: 0000000000000106 RAX: ffffffffffffffda RBX: 00007ffef532bee0 RCX: 00007f2912b11b0a RDX: 00007ffef532ba50 RSI: 00007ffef532bee0 RDI: 00000000ffffff9c RBP: 00005566d7dfc910 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffef532bae0 R13: 000055669e312100 R14: 0000000000000000 R15: 00007ffef532c500 rcu: rcu_preempt kthread timer wakeup didn't happen for 10505 jiffies! g11629 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 rcu: Possible timer handling issue on cpu=1 timer-softirq=8159 rcu: rcu_preempt kthread starved for 10506 jiffies! g11629 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->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:I stack:27224 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5325 [inline] __schedule+0x1798/0x4cc0 kernel/sched/core.c:6929 __schedule_loop kernel/sched/core.c:7011 [inline] schedule+0x165/0x360 kernel/sched/core.c:7026 schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x301/0x1540 kernel/rcu/tree.c:2083 rcu_gp_kthread+0x99/0x390 kernel/rcu/tree.c:2285 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x4bc/0x870 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245