FYI, we noticed the following commit (built with gcc-7):
commit: aa09766fd96b09ef68c4cc0e09869d16c1c11182 ("EXP rcu: Diagnostics for grace-period hangs")
https://git.kernel.org/cgit/linux/kernel/git/paulmck/linux-rcu.git dev.2018.04.27a
in testcase: boot
on test machine: qemu-system-x86_64 -enable-kvm -smp 2 -m 512M
caused below changes (please refer to attached dmesg/kmsg for entire log/backtrace):
+-----------------------------------------------------+------------+------------+
| | 248d0f34b4 | aa09766fd9 |
+-----------------------------------------------------+------------+------------+
| boot_successes | 64 | 37 |
| boot_failures | 0 | 27 |
| BUG:spinlock_trylock_failure_on_UP_on_CPU | 0 | 24 |
| RIP:_raw_spin_unlock_irqrestore | 0 | 23 |
| WARNING:at_kernel/rcu/tree.c:#rcu_process_callbacks | 0 | 27 |
| RIP:rcu_process_callbacks | 0 | 27 |
| RIP:___might_sleep | 0 | 2 |
| RIP:vma_interval_tree_remove | 0 | 1 |
+-----------------------------------------------------+------------+------------+
[ 14.509830] BUG: spinlock trylock failure on UP on CPU#0, rcu_torture_cbf/42
[ 14.511111] lock: rcu_preempt_state+0x0/0x7e0, .magic: dead4ead, .owner: rcu_torture_cbf/42, .owner_cpu: 0
[ 14.512833] CPU: 0 PID: 42 Comm: rcu_torture_cbf Tainted: G T 4.17.0-rc1-00053-gaa09766 #1
[ 14.513799] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1 04/01/2014
[ 14.513799] Call Trace:
[ 14.513799] <IRQ>
[ 14.513799] do_raw_spin_trylock+0x38/0x50
[ 14.513799] _raw_spin_lock_irqsave+0x49/0x80
[ 14.513799] ? rcu_process_callbacks+0x2a4/0x4c0
[ 14.513799] rcu_process_callbacks+0x2a4/0x4c0
[ 14.513799] __do_softirq+0xdd/0x1e1
[ 14.513799] irq_exit+0x50/0x70
[ 14.513799] smp_apic_timer_interrupt+0x73/0x80
[ 14.513799] apic_timer_interrupt+0xf/0x20
[ 14.513799] </IRQ>
[ 14.513799] RIP: 0010:_raw_spin_unlock_irqrestore+0x28/0x50
[ 14.513799] RSP: 0000:ffffc9000012fe18 EFLAGS: 00000206 ORIG_RAX: ffffffffffffff13
[ 14.513799] RAX: ffffffffffffffff RBX: 0000000000000206 RCX: 0000000000000001
[ 14.513799] RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000206
[ 14.513799] RBP: ffffffff83967c78 R08: 000000052b7f420f R09: 0000000000000001
[ 14.513799] R10: 0000000000000001 R11: 0000000000000000 R12: ffffc9000013d350
[ 14.513799] R13: ffffffff82800b20 R14: ffffffff83967c78 R15: 0000000000000206
[ 14.513799] debug_object_activate+0x165/0x210
[ 14.513799] ? rcu_torture_boost_cb+0x10/0x10
[ 14.513799] ? rcu_torture_err_cb+0x20/0x20
[ 14.513799] ? __call_rcu+0x2c/0x220
[ 14.513799] __call_rcu+0x2c/0x220
[ 14.513799] ? rcu_torture_boost_cb+0x10/0x10
[ 14.513799] ? rcu_torture_err_cb+0x20/0x20
[ 14.513799] rcu_torture_cbflood+0x10d/0x1a0
[ 14.513799] kthread+0x13d/0x150
[ 14.513799] ? kthread_create_on_node+0x70/0x70
[ 14.513799] ret_from_fork+0x35/0x40
[ 14.513799] rcu_check_gp_start_stall: g1424 0100 gar:301 ga:306 f0x1 rcu_preempt->state:0x0
[ 14.513799] WARNING: CPU: 0 PID: 42 at kernel/rcu/tree.c:2811 rcu_process_callbacks+0x396/0x4c0
[ 14.513799] Modules linked in:
[ 14.513799] CPU: 0 PID: 42 Comm: rcu_torture_cbf Tainted: G T 4.17.0-rc1-00053-gaa09766 #1
[ 14.513799] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1 04/01/2014
[ 14.513799] RIP: 0010:rcu_process_callbacks+0x396/0x4c0
[ 14.513799] RSP: 0000:ffffffff8262df10 EFLAGS: 00010086
[ 14.513799] RAX: 000000000000004f RBX: ffffffff82801a60 RCX: ffffffff8109126c
[ 14.513799] RDX: 0000000000000100 RSI: 0000000000000001 RDI: 00000000ffffffff
[ 14.513799] RBP: ffffffff82802240 R08: 0000000000000000 R09: 0000000000000001
[ 14.513799] R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000001
[ 14.513799] R13: ffffffff82801a60 R14: 0000000000000046 R15: 0000000000000000
[ 14.513799] FS: 0000000000000000(0000) GS:ffffffff8262a000(0000) knlGS:0000000000000000
[ 14.513799] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 14.513799] CR2: 0000000000000000 CR3: 000000000261b000 CR4: 00000000000006b0
[ 14.513799] Call Trace:
[ 14.513799] <IRQ>
[ 14.513799] __do_softirq+0xdd/0x1e1
[ 14.513799] irq_exit+0x50/0x70
[ 14.513799] smp_apic_timer_interrupt+0x73/0x80
[ 14.513799] apic_timer_interrupt+0xf/0x20
[ 14.513799] </IRQ>
[ 14.513799] RIP: 0010:_raw_spin_unlock_irqrestore+0x28/0x50
[ 14.513799] RSP: 0000:ffffc9000012fe18 EFLAGS: 00000206 ORIG_RAX: ffffffffffffff13
[ 14.513799] RAX: ffffffffffffffff RBX: 0000000000000206 RCX: 0000000000000001
[ 14.513799] RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000206
[ 14.513799] RBP: ffffffff83967c78 R08: 000000052b7f420f R09: 0000000000000001
[ 14.513799] R10: 0000000000000001 R11: 0000000000000000 R12: ffffc9000013d350
[ 14.513799] R13: ffffffff82800b20 R14: ffffffff83967c78 R15: 0000000000000206
[ 14.513799] debug_object_activate+0x165/0x210
[ 14.513799] ? rcu_torture_boost_cb+0x10/0x10
[ 14.513799] ? rcu_torture_err_cb+0x20/0x20
[ 14.513799] ? __call_rcu+0x2c/0x220
[ 14.513799] __call_rcu+0x2c/0x220
[ 14.513799] ? rcu_torture_boost_cb+0x10/0x10
[ 14.513799] ? rcu_torture_err_cb+0x20/0x20
[ 14.513799] rcu_torture_cbflood+0x10d/0x1a0
[ 14.513799] kthread+0x13d/0x150
[ 14.513799] ? kthread_create_on_node+0x70/0x70
[ 14.513799] ret_from_fork+0x35/0x40
[ 14.513799] Code: 2b b3 88 07 00 00 56 0f b6 83 af 01 00 00 48 c7 c6 60 98 00 82 50 44 0f b6 8b ae 01 00 00 44 0f b6 83 ad 01 00 00 e8 ad ca fe ff <0f> 0b 48 83 c4 30 4c 89 f6 48 89 df e8 49 74 ac 00 4c 89 f6 4c
[ 14.513799] ---[ end trace 38414e9fbee19859 ]---
To reproduce:
git clone https://github.com/intel/lkp-tests.git
cd lkp-tests
bin/lkp qemu -k <bzImage> job-script # job-script is attached in this email
Thanks,
Xiaolong