FYI, we noticed the below changes on https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git master commit 34578dc67f38c02ccbe696e4099967884caa8e15 ("printk: set may_schedule for some of console_trylock() callers") +------------------------------------------------+------------+------------+ | | 08e0722e8e | 34578dc67f | +------------------------------------------------+------------+------------+ | boot_successes | 0 | 0 | | boot_failures | 98 | 100 | | BUG:kernel_torture_test_oversize | 98 | 50 | | EIP_is_at_raw_spin_unlock_irqrestore | 0 | 3 | | Kernel_panic-not_syncing:softlockup:hung_tasks | 0 | 50 | | backtrace:of_unittest | 0 | 50 | | backtrace:kernel_init_freeable | 0 | 50 | | EIP_is_at_vprintk_emit | 0 | 28 | | EIP_is_at_lock_acquire | 0 | 5 | | EIP_is_at_of_unittest_overlay | 0 | 8 | | EIP_is_at_mutex_lock_nested | 0 | 1 | | EIP_is_at__mutex_unlock_slowpath | 0 | 2 | | EIP_is_at_of_overlay_destroy | 0 | 1 | | EIP_is_at_idr_find_slowpath | 0 | 1 | | EIP_is_at___might_sleep | 0 | 1 | +------------------------------------------------+------------+------------+ [ 33.497678] ### dt-test ### of_unittest_destroy_tracked_overlays: overlay destroy failed for #6 [ 33.497693] NMI watchdog: BUG: soft lockup - CPU#0 stuck for 23s! [swapper:1] [ 33.497693] NMI watchdog: BUG: soft lockup - CPU#0 stuck for 23s! [swapper:1] [ 33.497695] Modules linked in: [ 33.497695] Modules linked in: [ 33.497696] irq event stamp: 69018756 [ 33.497696] irq event stamp: 69018756 [ 33.497700] hardirqs last enabled at (69018755): [] vprintk_emit+0x1e5/0x600 [ 33.497700] hardirqs last enabled at (69018755): [] vprintk_emit+0x1e5/0x600 [ 33.497704] hardirqs last disabled at (69018756): [] apic_timer_interrupt+0x28/0x40 [ 33.497704] hardirqs last disabled at (69018756): [] apic_timer_interrupt+0x28/0x40 [ 33.497707] softirqs last enabled at (68988726): [] __do_softirq+0x312/0x3f0 [ 33.497707] softirqs last enabled at (68988726): [] __do_softirq+0x312/0x3f0 [ 33.497710] softirqs last disabled at (68988719): [] do_softirq_own_stack+0x1e/0x30 [ 33.497710] softirqs last disabled at (68988719): [] do_softirq_own_stack+0x1e/0x30 [ 33.497713] CPU: 0 PID: 1 Comm: swapper Not tainted 4.5.0-rc4-00295-g34578dc #1 [ 33.497713] CPU: 0 PID: 1 Comm: swapper Not tainted 4.5.0-rc4-00295-g34578dc #1 [ 33.497714] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Debian-1.8.2-1 04/01/2014 [ 33.497714] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Debian-1.8.2-1 04/01/2014 [ 33.497715] task: b0058000 ti: b0060000 task.ti: b0060000 [ 33.497715] task: b0058000 ti: b0060000 task.ti: b0060000 [ 33.497716] EIP: 0060:[] EFLAGS: 00000246 CPU: 0 [ 33.497716] EIP: 0060:[] EFLAGS: 00000246 CPU: 0 [ 33.497718] EIP is at vprintk_emit+0x1ea/0x600 [ 33.497718] EIP is at vprintk_emit+0x1ea/0x600 [ 33.497719] EAX: 00000246 EBX: 00000053 ECX: 00000000 EDX: 00000001 [ 33.497719] EAX: 00000246 EBX: 00000053 ECX: 00000000 EDX: 00000001 [ 33.497720] ESI: 00000006 EDI: 00000000 EBP: b0061e4c ESP: b0061e1c [ 33.497720] ESI: 00000006 EDI: 00000000 EBP: b0061e4c ESP: b0061e1c [ 33.497721] DS: 007b ES: 007b FS: 0000 GS: 0000 SS: 0068 [ 33.497721] DS: 007b ES: 007b FS: 0000 GS: 0000 SS: 0068 [ 33.497722] CR0: 8005003b CR2: 00000000 CR3: 10e3d000 CR4: 00000690 [ 33.497722] CR0: 8005003b CR2: 00000000 CR3: 10e3d000 CR4: 00000690 [ 33.497726] Stack: [ 33.497726] Stack: [ 33.497730] 00000000 00000000 00000000 00000000 c15d9462 00000053 c15d9462 00000000 [ 33.497730] 00000000 00000000 00000000 00000000 c15d9462 00000053 c15d9462 00000000 [ 33.497734] 00000246 00000006 00000001 00000000 b0061e6c c068e712 00000000 00000004 [ 33.497734] 00000246 00000006 00000001 00000000 b0061e6c c068e712 00000000 00000004 [ 33.497737] 00000000 00000000 c0bcf58c b0061e80 b0061e74 c06fdf6e b0061ea4 c0df5eec [ 33.497737] 00000000 00000000 c0bcf58c b0061e80 b0061e74 c06fdf6e b0061ea4 c0df5eec [ 33.497738] Call Trace: [ 33.497738] Call Trace: [ 33.497741] [] vprintk_default+0x32/0x40 [ 33.497741] [] vprintk_default+0x32/0x40 [ 33.497744] [] printk+0x11/0x13 [ 33.497744] [] printk+0x11/0x13 [ 33.497748] [] of_unittest_overlay+0x8d1/0x900 [ 33.497748] [] of_unittest_overlay+0x8d1/0x900 [ 33.497750] [] of_unittest+0xc04/0xc2d [ 33.497750] [] of_unittest+0xc04/0xc2d [ 33.497753] [] ? trace_hardirqs_on+0xb/0x10 [ 33.497753] [] ? trace_hardirqs_on+0xb/0x10 [ 33.497756] [] ? add_sysfs_fw_map_entry+0x3c/0x7d [ 33.497756] [] ? add_sysfs_fw_map_entry+0x3c/0x7d [ 33.497758] [] ? do_one_initcall+0x73/0x1d0 [ 33.497758] [] ? do_one_initcall+0x73/0x1d0 [ 33.497760] [] ? of_unittest_overlay+0x900/0x900 [ 33.497760] [] ? of_unittest_overlay+0x900/0x900 [ 33.497761] [] do_one_initcall+0x7e/0x1d0 [ 33.497761] [] do_one_initcall+0x7e/0x1d0 [ 33.497763] [] ? of_unittest_overlay+0x900/0x900 [ 33.497763] [] ? of_unittest_overlay+0x900/0x900 [ 33.497765] [] ? parse_args+0x24f/0x440 [ 33.497765] [] ? parse_args+0x24f/0x440 [ 33.497767] [] ? trace_hardirqs_on+0xb/0x10 [ 33.497767] [] ? trace_hardirqs_on+0xb/0x10 [ 33.497770] [] ? kernel_init_freeable+0xc3/0x15b [ 33.497770] [] ? kernel_init_freeable+0xc3/0x15b [ 33.497771] [] kernel_init_freeable+0xe0/0x15b [ 33.497771] [] kernel_init_freeable+0xe0/0x15b [ 33.497773] [] kernel_init+0xb/0xe0 [ 33.497773] [] kernel_init+0xb/0xe0 [ 33.497776] [] ? schedule_tail+0xc/0x50 [ 33.497776] [] ? schedule_tail+0xc/0x50 [ 33.497778] [] ret_from_kernel_thread+0x20/0x40 [ 33.497778] [] ret_from_kernel_thread+0x20/0x40 [ 33.497779] [] ? rest_init+0x110/0x110 [ 33.497779] [] ? rest_init+0x110/0x110 [ 33.497804] Code: 00 8d 40 ff 80 b8 60 94 5d c1 0a 0f 85 d0 fe ff ff 89 c3 be 02 00 00 00 e9 c6 fe ff ff 8d 74 26 00 e8 0b 11 ff ff 8b 45 f0 50 9d <8d> 74 26 00 80 7d ef 00 0f 85 7e ff ff ff e8 73 ce fe ff e8 fe [ 33.497804] Code: 00 8d 40 ff 80 b8 60 94 5d c1 0a 0f 85 d0 fe ff ff 89 c3 be 02 00 00 00 e9 c6 fe ff ff 8d 74 26 00 e8 0b 11 ff ff 8b 45 f0 50 9d <8d> 74 26 00 80 7d ef 00 0f 85 7e ff ff ff e8 73 ce fe ff e8 fe [ 33.497805] Kernel panic - not syncing: softlockup: hung tasks [ 33.497805] Kernel panic - not syncing: softlockup: hung tasks [ 33.497807] CPU: 0 PID: 1 Comm: swapper Tainted: G L 4.5.0-rc4-00295-g34578dc #1 [ 33.497807] CPU: 0 PID: 1 Comm: swapper Tainted: G L 4.5.0-rc4-00295-g34578dc #1 [ 33.497808] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Debian-1.8.2-1 04/01/2014 [ 33.497808] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Debian-1.8.2-1 04/01/2014 [ 33.497812] b0058000 b0061cf8 c07c681d b0061d10 c06fdaf6 b0058000 00000017 b0058000 [ 33.497812] b0058000 b0061cf8 c07c681d b0061d10 c06fdaf6 b0058000 00000017 b0058000 [ 33.497815] 00000000 b0061d40 c06c11cd c0b7dd9b 00000000 00000017 b0058298 00000001 [ 33.497815] 00000000 b0061d40 c06c11cd c0b7dd9b 00000000 00000017 b0058298 00000001 [ 33.497819] b0061de0 00000008 c0d799a0 c0d760c0 7fffffff b0061d7c c069b960 00000000 [ 33.497819] b0061de0 00000008 c0d799a0 c0d760c0 7fffffff b0061d7c c069b960 00000000 [ 33.497819] Call Trace: [ 33.497819] Call Trace: [ 33.497821] [] dump_stack+0x16/0x19 [ 33.497821] [] dump_stack+0x16/0x19 [ 33.497823] [] panic+0x85/0x190 [ 33.497823] [] panic+0x85/0x190 [ 33.497825] [] watchdog_timer_fn+0x1ad/0x1b0 [ 33.497825] [] watchdog_timer_fn+0x1ad/0x1b0 [ 33.497828] [] hrtimer_run_queues+0x140/0x4a0 [ 33.497828] [] hrtimer_run_queues+0x140/0x4a0 [ 33.497829] [] ? watchdog+0x40/0x40 [ 33.497829] [] ? watchdog+0x40/0x40 [ 33.497831] [] update_process_times+0x1b/0x50 [ 33.497831] [] update_process_times+0x1b/0x50 [ 33.497834] [] tick_periodic+0x34/0xd0 [ 33.497834] [] tick_periodic+0x34/0xd0 [ 33.497836] [] ? tick_handle_periodic+0x14/0x60 [ 33.497836] [] ? tick_handle_periodic+0x14/0x60 [ 33.497837] [] tick_handle_periodic+0x14/0x60 [ 33.497837] [] tick_handle_periodic+0x14/0x60 [ 33.497841] [] local_apic_timer_interrupt+0x20/0x50 [ 33.497841] [] local_apic_timer_interrupt+0x20/0x50 [ 33.497843] [] smp_apic_timer_interrupt+0x2c/0x40 [ 33.497843] [] smp_apic_timer_interrupt+0x2c/0x40 [ 33.497844] [] apic_timer_interrupt+0x2f/0x40 [ 33.497844] [] apic_timer_interrupt+0x2f/0x40 [ 33.497846] [] ? vprintk_emit+0x1ea/0x600 [ 33.497846] [] ? vprintk_emit+0x1ea/0x600 [ 33.497848] [] vprintk_default+0x32/0x40 [ 33.497848] [] vprintk_default+0x32/0x40 [ 33.497850] [] printk+0x11/0x13 [ 33.497850] [] printk+0x11/0x13 [ 33.497852] [] of_unittest_overlay+0x8d1/0x900 [ 33.497852] [] of_unittest_overlay+0x8d1/0x900 [ 33.497854] [] of_unittest+0xc04/0xc2d [ 33.497854] [] of_unittest+0xc04/0xc2d [ 33.497855] [] ? trace_hardirqs_on+0xb/0x10 [ 33.497855] [] ? trace_hardirqs_on+0xb/0x10 [ 33.497857] [] ? add_sysfs_fw_map_entry+0x3c/0x7d [ 33.497857] [] ? add_sysfs_fw_map_entry+0x3c/0x7d [ 33.497859] [] ? do_one_initcall+0x73/0x1d0 [ 33.497859] [] ? do_one_initcall+0x73/0x1d0 [ 33.497861] [] ? of_unittest_overlay+0x900/0x900 [ 33.497861] [] ? of_unittest_overlay+0x900/0x900 [ 33.497862] [] do_one_initcall+0x7e/0x1d0 [ 33.497862] [] do_one_initcall+0x7e/0x1d0 [ 33.497864] [] ? of_unittest_overlay+0x900/0x900 [ 33.497864] [] ? of_unittest_overlay+0x900/0x900 [ 33.497866] [] ? parse_args+0x24f/0x440 [ 33.497866] [] ? parse_args+0x24f/0x440 [ 33.497867] [] ? trace_hardirqs_on+0xb/0x10 [ 33.497867] [] ? trace_hardirqs_on+0xb/0x10 [ 33.497869] [] ? kernel_init_freeable+0xc3/0x15b [ 33.497869] [] ? kernel_init_freeable+0xc3/0x15b [ 33.497871] [] kernel_init_freeable+0xe0/0x15b [ 33.497871] [] kernel_init_freeable+0xe0/0x15b [ 33.497872] [] kernel_init+0xb/0xe0 [ 33.497872] [] kernel_init+0xb/0xe0 [ 33.497874] [] ? schedule_tail+0xc/0x50 [ 33.497874] [] ? schedule_tail+0xc/0x50 [ 33.497876] [] ret_from_kernel_thread+0x20/0x40 [ 33.497876] [] ret_from_kernel_thread+0x20/0x40 [ 33.497877] [] ? rest_init+0x110/0x110 [ 33.497877] [] ? rest_init+0x110/0x110 [ 33.497881] Kernel Offset: 0xf600000 from 0xb1000000 (relocation range: 0xb0000000-0xc47dffff) [ 33.497881] Kernel Offset: 0xf600000 from 0xb1000000 (relocation range: 0xb0000000-0xc47dffff) Thanks, Ying Huang