rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	0-....: (1 GPs behind) idle=90ac/1/0x4000000000000000 softirq=47068/47069 fqs=5172
rcu: 	         hardirqs   softirqs   csw/system
rcu: 	 number:     8312          0            0
rcu: 	cputime:      190      52299           11   ==> 52490(ms)
rcu: 	(t=10500 jiffies g=43433 q=4639 ncpus=2)
CPU: 0 UID: 0 PID: 11783 Comm: syz.4.1408 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:qdisc_peek_head+0x29/0x40 include/net/sch_generic.h:1134
Code: 90 f3 0f 1e fa 53 48 89 fb e8 93 ee 6c f8 48 81 c3 d8 00 00 00 48 89 d8 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df 80 3c 08 00 <74> 08 48 89 df e8 fd af d2 f8 48 8b 03 5b e9 44 0f f7 01 cc 0f 1f
RSP: 0018:ffffc90000007ac8 EFLAGS: 00000246
RAX: 1ffff1100fbda41b RBX: ffff88807ded20d8 RCX: dffffc0000000000
RDX: 0000000000000100 RSI: 0000000000000000 RDI: ffff88807ded2000
RBP: ffff88802723f800 R08: 0000000000000000 R09: ffffffff895fbcb6
R10: 0000000000000001 R11: ffffffff89531520 R12: dffffc0000000000
R13: ffff888026de4000 R14: ffff88807ded2000 R15: ffffffff8f7d8b78
FS:  00007f2cdc8726c0(0000) GS:ffff888126135000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffbad20ff98 CR3: 000000005aa62000 CR4: 00000000003526f0
Call Trace:
 <IRQ>
 taprio_dequeue_from_txq+0x174/0x900 net/sched/sch_taprio.c:725
 taprio_dequeue_tc_priority+0x1ac/0x750 net/sched/sch_taprio.c:792
 taprio_dequeue+0x186/0x550 net/sched/sch_taprio.c:-1
 dequeue_skb net/sched/sch_generic.c:297 [inline]
 qdisc_restart net/sched/sch_generic.c:402 [inline]
 __qdisc_run+0x23f/0x1540 net/sched/sch_generic.c:420
 qdisc_run+0xc5/0x290 include/net/pkt_sched.h:120
 net_tx_action+0x7c9/0x980 net/core/dev.c:5774
 handle_softirqs+0x286/0x870 kernel/softirq.c:622
 __do_softirq kernel/softirq.c:656 [inline]
 invoke_softirq kernel/softirq.c:496 [inline]
 __irq_exit_rcu+0xca/0x1f0 kernel/softirq.c:723
 irq_exit_rcu+0x9/0x30 kernel/softirq.c:739
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1052 [inline]
 sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1052
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:__raw_spin_unlock_irq include/linux/spinlock_api_smp.h:160 [inline]
RIP: 0010:_raw_spin_unlock_irq+0x29/0x50 kernel/locking/spinlock.c:202
Code: 90 f3 0f 1e fa 53 48 89 fb 48 83 c7 18 48 8b 74 24 08 e8 aa 8a 53 f6 48 89 df e8 02 22 54 f6 e8 9d ea 7d f6 fb bf 01 00 00 00 <e8> e2 18 46 f6 65 8b 05 3b d8 24 07 85 c0 74 07 5b c3 cc cc cc cc
RSP: 0018:ffffc9000adff430 EFLAGS: 00000286
RAX: a543314bc5dd1900 RBX: ffff888030781710 RCX: a543314bc5dd1900
RDX: 0000000000000007 RSI: ffffffff8d7113f9 RDI: 0000000000000001
RBP: ffffc9000adff570 R08: ffffffff8f7d0477 R09: 1ffffffff1efa08e
R10: dffffc0000000000 R11: fffffbfff1efa08f R12: ffffc9000adff4c0
R13: 00000003fffffffc R14: 0000000000000000 R15: ffff88805c763c80
 spin_unlock_irq include/linux/spinlock.h:401 [inline]
 shmem_add_to_page_cache+0x8ee/0xba0 mm/shmem.c:910
 shmem_alloc_and_add_folio+0x829/0xf40 mm/shmem.c:1938
 shmem_get_folio_gfp+0x59d/0x1660 mm/shmem.c:2535
 shmem_fault+0x179/0x390 mm/shmem.c:2736
 __do_fault+0x138/0x390 mm/memory.c:5281
 do_read_fault mm/memory.c:5716 [inline]
 do_fault mm/memory.c:5850 [inline]
 do_pte_missing mm/memory.c:4362 [inline]
 handle_pte_fault mm/memory.c:6195 [inline]
 __handle_mm_fault+0x35e3/0x5400 mm/memory.c:6336
 handle_mm_fault+0x40a/0x8e0 mm/memory.c:6505
 faultin_page mm/gup.c:1126 [inline]
 __get_user_pages+0x165c/0x2a00 mm/gup.c:1428
 populate_vma_page_range+0x29f/0x3a0 mm/gup.c:1860
 __mm_populate+0x24c/0x380 mm/gup.c:1963
 mm_populate include/linux/mm.h:3478 [inline]
 vm_mmap_pgoff+0x387/0x4d0 mm/util.c:586
 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: 0033:0x7f2cdb98f749
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f2cdc872038 EFLAGS: 00000246 ORIG_RAX: 0000000000000009
RAX: ffffffffffffffda RBX: 00007f2cdbbe6180 RCX: 00007f2cdb98f749
RDX: 0000000000000003 RSI: 0000000000b36000 RDI: 0000200000000000
RBP: 00007f2cdba13f91 R08: ffffffffffffffff R09: 0000000000000000
R10: 0000000000008031 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f2cdbbe6218 R14: 00007f2cdbbe6180 R15: 00007ffd4c4575d8
 </TASK>
sched: DL replenish lagged too much