Hello,
kernel test robot noticed
"WARNING:at_kernel/rcu/tree_exp.h:#__sync_rcu_exp_select_node_cpus" on:
commit: 1fccb15145eb73b06af682aff47acfe47235f139 ("rcu/exp: Warn on CPU lagging
for too long within hotplug IPI's blindspot")
https://github.com/paulmckrcu/linux dev.2025.06.06a
in testcase: rcutorture
version:
with following parameters:
runtime: 300s
test: cpuhotplug
torture_type: rcu
config: x86_64-randconfig-007-20250609
compiler: gcc-12
test machine: qemu-system-x86_64 -enable-kvm -cpu SandyBridge -smp 2 -m 16G
(please refer to attached dmesg/kmsg for entire log/backtrace)
If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <[email protected]>
| Closes: https://lore.kernel.org/oe-lkp/[email protected]
[ 326.392305][ T17] ------------[ cut here ]------------
[ 326.395249][ T17] WARNING: CPU: 0 PID: 17 at kernel/rcu/tree_exp.h:419
__sync_rcu_exp_select_node_cpus
(kbuild/obj/consumer/x86_64-randconfig-007-20250609/kernel/rcu/tree_exp.h:419
(discriminator 1))
[ 326.398772][ T17] Modules linked in: rcutorture torture
[ 326.401711][ T17] CPU: 0 UID: 0 PID: 17 Comm: rcu_exp_gp_kthr Not tainted
6.15.0-rc1-00059-g1fccb15145eb #1 PREEMPT(full)
c83de7334379d04ea860ac9db4e3031d8be8de51
[ 326.407801][ T17] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996),
BIOS 1.16.2-debian-1.16.2-1 04/01/2014
[ 326.411423][ T17] RIP: 0010:__sync_rcu_exp_select_node_cpus
(kbuild/obj/consumer/x86_64-randconfig-007-20250609/kernel/rcu/tree_exp.h:419
(discriminator 1))
[ 326.414685][ T17] Code: 85 c0 74 02 0f 0b 48 8b 75 98 48 8b 7d b8 ff 45 a8 e8
c4 dd 5a 04 bf 01 00 00 00 e8 f7 c5 5a 04 83 7d a8 0a 0f 8e 8d fe ff ff <0f> 0b
e9 86 fe ff ff 48 8b 55 d0 b8 ff ff 37 00 48 c1 e0 2a 48 c1
All code
========
0: 85 c0 test %eax,%eax
2: 74 02 je 0x6
4: 0f 0b ud2
6: 48 8b 75 98 mov -0x68(%rbp),%rsi
a: 48 8b 7d b8 mov -0x48(%rbp),%rdi
e: ff 45 a8 incl -0x58(%rbp)
11: e8 c4 dd 5a 04 call 0x45addda
16: bf 01 00 00 00 mov $0x1,%edi
1b: e8 f7 c5 5a 04 call 0x45ac617
20: 83 7d a8 0a cmpl $0xa,-0x58(%rbp)
24: 0f 8e 8d fe ff ff jle 0xfffffffffffffeb7
2a:* 0f 0b ud2 <-- trapping instruction
2c: e9 86 fe ff ff jmp 0xfffffffffffffeb7
31: 48 8b 55 d0 mov -0x30(%rbp),%rdx
35: b8 ff ff 37 00 mov $0x37ffff,%eax
3a: 48 c1 e0 2a shl $0x2a,%rax
3e: 48 rex.W
3f: c1 .byte 0xc1
Code starting with the faulting instruction
===========================================
0: 0f 0b ud2
2: e9 86 fe ff ff jmp 0xfffffffffffffe8d
7: 48 8b 55 d0 mov -0x30(%rbp),%rdx
b: b8 ff ff 37 00 mov $0x37ffff,%eax
10: 48 c1 e0 2a shl $0x2a,%rax
14: 48 rex.W
15: c1 .byte 0xc1
[ 326.421654][ T17] RSP: 0018:ffffc9000011fd30 EFLAGS: 00010202
[ 326.424977][ T17] RAX: 0000000000000000 RBX: ffffffff8837a488 RCX:
0000000000000000
[ 326.428491][ T17] RDX: 0000000000000000 RSI: 0000000000000006 RDI:
fffff52000023f7c
[ 326.432035][ T17] RBP: ffffc9000011fdc0 R08: 0000000000000008 R09:
0000000000000000
[ 326.435624][ T17] R10: fffffbfff147169b R11: ffffffff815ac0e5 R12:
ffff8883ae954240
[ 326.439162][ T17] R13: dffffc0000000000 R14: 0000000000000002 R15:
0000000000000001
[ 326.442708][ T17] FS: 0000000000000000(0000) GS:ffff8884241ef000(0000)
knlGS:0000000000000000
[ 326.446372][ T17] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 326.449774][ T17] CR2: 000000000805b740 CR3: 0000000153efc000 CR4:
00000000000406f0
[ 326.453432][ T17] DR0: 0000000000000000 DR1: 0000000000000000 DR2:
0000000000000000
[ 326.456814][ T17] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7:
0000000000000400
[ 326.460466][ T17] Call Trace:
[ 326.463548][ T17] <TASK>
[ 326.466479][ T17] sync_rcu_exp_select_node_cpus
(kbuild/obj/consumer/x86_64-randconfig-007-20250609/kernel/rcu/tree_exp.h:466)
[ 326.469763][ T17] sync_rcu_exp_select_cpus
(kbuild/obj/consumer/x86_64-randconfig-007-20250609/kernel/rcu/tree_exp.h:533)
[ 326.473086][ T17] wait_rcu_exp_gp
(kbuild/obj/consumer/x86_64-randconfig-007-20250609/kernel/rcu/tree_exp.h:731
kbuild/obj/consumer/x86_64-randconfig-007-20250609/kernel/rcu/tree_exp.h:502)
[ 326.476305][ T17] kthread_worker_fn
(kbuild/obj/consumer/x86_64-randconfig-007-20250609/arch/x86/include/asm/jump_label.h:36
kbuild/obj/consumer/x86_64-randconfig-007-20250609/include/trace/events/sched.h:119
kbuild/obj/consumer/x86_64-randconfig-007-20250609/kernel/kthread.c:1015)
[ 326.479478][ T17] ? __kasan_check_read
(kbuild/obj/consumer/x86_64-randconfig-007-20250609/mm/kasan/shadow.c:32)
[ 326.482614][ T17] ? strict_work_handler
(kbuild/obj/consumer/x86_64-randconfig-007-20250609/kernel/rcu/tree_exp.h:498)
[ 326.485790][ T17] ? kthread_flush_work
(kbuild/obj/consumer/x86_64-randconfig-007-20250609/kernel/kthread.c:971)
[ 326.488992][ T17] kthread
(kbuild/obj/consumer/x86_64-randconfig-007-20250609/kernel/kthread.c:464)
[ 326.492081][ T17] ? preempt_latency_stop
(kbuild/obj/consumer/x86_64-randconfig-007-20250609/kernel/sched/core.c:5876)
[ 326.495175][ T17] ? kthread_is_per_cpu
(kbuild/obj/consumer/x86_64-randconfig-007-20250609/kernel/kthread.c:413)
[ 326.497975][ T17] ? _raw_spin_unlock_irq
(kbuild/obj/consumer/x86_64-randconfig-007-20250609/arch/x86/include/asm/preempt.h:104
kbuild/obj/consumer/x86_64-randconfig-007-20250609/include/linux/spinlock_api_smp.h:160
kbuild/obj/consumer/x86_64-randconfig-007-20250609/kernel/locking/spinlock.c:202)
[ 326.501111][ T17] ? calculate_sigpending
(kbuild/obj/consumer/x86_64-randconfig-007-20250609/kernel/signal.c:195)
[ 326.504292][ T17] ? kthread_is_per_cpu
(kbuild/obj/consumer/x86_64-randconfig-007-20250609/kernel/kthread.c:413)
[ 326.507344][ T17] ret_from_fork
(kbuild/obj/consumer/x86_64-randconfig-007-20250609/arch/x86/kernel/process.c:159)
[ 326.510341][ T17] ? kthread_is_per_cpu
(kbuild/obj/consumer/x86_64-randconfig-007-20250609/kernel/kthread.c:413)
[ 326.513345][ T17] ret_from_fork_asm
(kbuild/obj/consumer/x86_64-randconfig-007-20250609/arch/x86/entry/entry_64.S:258)
[ 326.516352][ T17] </TASK>
[ 326.519111][ T17] irq event stamp: 974697
[ 326.521876][ T17] hardirqs last enabled at (974711): __up_console_sem
(kbuild/obj/consumer/x86_64-randconfig-007-20250609/arch/x86/include/asm/irqflags.h:26
(discriminator 1)
kbuild/obj/consumer/x86_64-randconfig-007-20250609/arch/x86/include/asm/irqflags.h:109
(discriminator 1)
kbuild/obj/consumer/x86_64-randconfig-007-20250609/arch/x86/include/asm/irqflags.h:151
(discriminator 1)
kbuild/obj/consumer/x86_64-randconfig-007-20250609/kernel/printk/printk.c:344
(discriminator 1))
[ 326.525370][ T17] hardirqs last disabled at (974724): __up_console_sem
(kbuild/obj/consumer/x86_64-randconfig-007-20250609/kernel/printk/printk.c:342
(discriminator 1))
[ 326.528804][ T17] softirqs last enabled at (974422): handle_softirqs
(kbuild/obj/consumer/x86_64-randconfig-007-20250609/arch/x86/include/asm/preempt.h:27
kbuild/obj/consumer/x86_64-randconfig-007-20250609/kernel/softirq.c:426
kbuild/obj/consumer/x86_64-randconfig-007-20250609/kernel/softirq.c:607)
[ 326.532296][ T17] softirqs last disabled at (974411): __do_softirq
(kbuild/obj/consumer/x86_64-randconfig-007-20250609/kernel/softirq.c:614)
[ 326.535643][ T17] ---[ end trace 0000000000000000 ]---
[ 326.717325][ T1035] smpboot: CPU 1 is now offline
[ 326.743123][ T886] smpboot: Booting Node 0 Processor 1 APIC 0x1
[ 326.747940][ T0] Masked ExtINT on CPU#1
[ 326.806808][ T1035] smpboot: CPU 1 is now offline
[ 326.836198][ T886] smpboot: Booting Node 0 Processor 1 APIC 0x1
[ 326.841248][ T0] Masked ExtINT on CPU#1
[ 326.907274][ T1035] smpboot: CPU 1 is now offline
[ 326.932209][ T886] smpboot: Booting Node 0 Processor 1 APIC 0x1
[ 326.936569][ T0] Masked ExtINT on CPU#1
The kernel config and materials to reproduce are available at:
https://download.01.org/0day-ci/archive/20250612/[email protected]
--
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki
