rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	1-....: (10499 ticks this GP) idle=f6ec/1/0x4000000000000000 softirq=14880/14888 fqs=5249
rcu: 	         hardirqs   softirqs   csw/system
rcu: 	 number:  1002566          0            0
rcu: 	cputime:    25205      27294           91   ==> 52510(ms)
rcu: 	(t=10502 jiffies g=7377 q=2786 ncpus=2)
CPU: 1 UID: 0 PID: 6270 Comm: syz.2.178 Not tainted 6.16.0-rc6-syzkaller-00434-gcd7c97f4584a #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
RIP: 0010:rcu_read_unlock_special+0x87/0x4c0
Code: f1 f1 f1 00 f2 f2 f2 4a 89 04 2b 66 42 c7 44 2b 09 f3 f3 42 c6 44 2b 0b f3 65 44 8b 35 92 37 f8 10 41 f7 c6 00 00 f0 00 74 49 <48> c7 44 24 40 0e 36 e0 45 4a c7 04 2b 00 00 00 00 66 42 c7 44 2b
RSP: 0018:ffffc900001e05e0 EFLAGS: 00000206
RAX: 70a77c1d8f9a8800 RBX: 1ffff9200003c0c4 RCX: 70a77c1d8f9a8800
RDX: 0000000000000002 RSI: ffffffff8d9986f9 RDI: ffffffff8be29f80
RBP: ffffc900001e06d8 R08: ffffffff8fa1e8f7 R09: 1ffffffff1f43d1e
R10: dffffc0000000000 R11: fffffbfff1f43d1f R12: ffffffff8e144400
R13: dffffc0000000000 R14: 0000000000000246 R15: 0000000000000002
FS:  00007f0fd8de76c0(0000) GS:ffff8881a3c1f000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f6dd42e56c0 CR3: 00000001115f0000 CR4: 00000000000006f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 <IRQ>
 __rcu_read_unlock+0x84/0xe0
 unwind_next_frame+0x19ae/0x2390
 arch_stack_walk+0x11c/0x150
 stack_trace_save+0x9c/0xe0
 kasan_save_track+0x3e/0x80
 kasan_save_free_info+0x46/0x50
 __kasan_slab_free+0x62/0x70
 kmem_cache_free+0x18f/0x400
 rcu_core+0xca8/0x1710
 handle_softirqs+0x286/0x870
 __irq_exit_rcu+0xca/0x1f0
 irq_exit_rcu+0x9/0x30
 sysvec_apic_timer_interrupt+0xa6/0xc0
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20
RIP: 0010:raw_spin_rq_unlock_irq+0x13/0x90
Code: cc e8 f1 7d db 09 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 41 57 41 56 53 66 90 e8 44 0b de 09 e8 bf 9f 34 00 fb 5b <41> 5e 41 5f c3 cc cc cc cc cc f3 0f 1e fa 49 be 00 00 00 00 00 fc
RSP: 0018:ffffc90006b87268 EFLAGS: 00000286
RAX: 70a77c1d8f9a8800 RBX: ffff88810a305dc0 RCX: 70a77c1d8f9a8800
RDX: 0000000000000006 RSI: ffffffff8d9986f9 RDI: ffffffff8be29f80
RBP: ffffc90006b87490 R08: ffffffff8fa1e8f7 R09: 1ffffffff1f43d1e
R10: dffffc0000000000 R11: fffffbfff1f43d1f R12: ffff88810a305640
R13: dffffc0000000000 R14: ffff88810a305640 R15: ffff888136639fc0
 __schedule+0x1948/0x4d00
 preempt_schedule_common+0x83/0xd0
 preempt_schedule+0xae/0xc0
 preempt_schedule_thunk+0x16/0x30
 _raw_spin_unlock_irqrestore+0xfd/0x110
 rcu_preempt_deferred_qs_irqrestore+0x851/0xc40
 rcu_read_unlock_special+0x3fe/0x4c0
 __rcu_read_unlock+0x84/0xe0
 kernfs_root+0x1ea/0x230
 kernfs_link_sibling+0xe6/0x3e0
 kernfs_add_one+0x1e0/0x520
 __kernfs_create_file+0x22b/0x2e0
 cgroup_addrm_files+0x7f2/0xb20
 css_populate_dir+0x2c4/0x3d0
 cgroup_mkdir+0xc20/0xe60
 kernfs_iop_mkdir+0x211/0x350
 vfs_mkdir+0x306/0x510
 do_mkdirat+0x247/0x590
 __x64_sys_mkdir+0x6c/0x80
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f0fd7f8eb69
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:00007f0fd8de7038 EFLAGS: 00000246 ORIG_RAX: 0000000000000053
RAX: ffffffffffffffda RBX: 00007f0fd81b6080 RCX: 00007f0fd7f8eb69
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000200000000000
RBP: 00007f0fd8011df1 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f0fd81b6080 R15: 00007ffeb84793d8
 </TASK>
sched: DL replenish lagged too much
