FYI, we noticed the below changes on https://github.com/0day-ci/linux Sergey-Senozhatsky/printk-move-can_use_console-out-of-console_trylock_for_printk/20160213-024210 commit af097cab1b878d5be746be8bcaa9a79986716c41 ("printk: set may_schedule for some of console_trylock callers") +------------------------------------------------+------------+------------+ | | 0a94edb5a8 | af097cab1b | +------------------------------------------------+------------+------------+ | boot_successes | 0 | 0 | | boot_failures | 122 | 122 | | BUG:kernel_boot_oversize | 122 | 29 | | backtrace:acpi_get_cpuid | 122 | 122 | | backtrace:early_init_pdc | 122 | 122 | | backtrace:acpi_early_processor_set_pdc | 122 | 122 | | backtrace:acpi_init | 122 | 122 | | backtrace:kernel_init_freeable | 122 | 122 | | EIP_is_at_vprintk_emit | 0 | 42 | | Kernel_panic-not_syncing:softlockup:hung_tasks | 0 | 93 | | backtrace:of_unittest | 0 | 76 | | EIP_is_at_mutex_lock_nested | 0 | 12 | | EIP_is_at_of_unittest | 0 | 17 | | backtrace:apic_timer_interrupt | 0 | 17 | | EIP_is_at__mutex_unlock_slowpath | 0 | 11 | | EIP_is_at_raw_spin_unlock_irqrestore | 0 | 5 | | EIP_is_at__do_softirq | 0 | 1 | | EIP_is_at_lock_acquire | 0 | 3 | | EIP_is_at_debug_lockdep_rcu_enabled | 0 | 1 | | EIP_is_at_lock_is_held | 0 | 1 | +------------------------------------------------+------------+------------+ [ 37.263139] of_overlay_destroy: Could not find overlay #6 [ 37.263179] NMI watchdog: BUG: soft lockup - CPU#0 stuck for 22s! [swapper:1] [ 37.263179] NMI watchdog: BUG: soft lockup - CPU#0 stuck for 22s! [swapper:1] [ 37.263184] Modules linked in: [ 37.263184] Modules linked in: [ 37.263187] irq event stamp: 9518968 [ 37.263187] irq event stamp: 9518968 [ 37.263202] hardirqs last enabled at (9518967): [] vprintk_emit+0xa6e/0xb5c [ 37.263202] hardirqs last enabled at (9518967): [] vprintk_emit+0xa6e/0xb5c [ 37.263214] hardirqs last disabled at (9518968): [] apic_timer_interrupt+0x28/0x40 [ 37.263214] hardirqs last disabled at (9518968): [] apic_timer_interrupt+0x28/0x40 [ 37.263227] softirqs last enabled at (9516854): [] __do_softirq+0x6f4/0x832 [ 37.263227] softirqs last enabled at (9516854): [] __do_softirq+0x6f4/0x832 [ 37.263239] softirqs last disabled at (9516847): [] do_softirq_own_stack+0x67/0x8a [ 37.263239] softirqs last disabled at (9516847): [] do_softirq_own_stack+0x67/0x8a [ 37.263248] CPU: 0 PID: 1 Comm: swapper Not tainted 4.5.0-rc3-00002-gaf097ca #1 [ 37.263248] CPU: 0 PID: 1 Comm: swapper Not tainted 4.5.0-rc3-00002-gaf097ca #1 [ 37.263253] task: cac29000 ti: cac2a000 task.ti: cac2a000 [ 37.263253] task: cac29000 ti: cac2a000 task.ti: cac2a000 [ 37.263259] EIP: 0060:[] EFLAGS: 00000246 CPU: 0 [ 37.263259] EIP: 0060:[] EFLAGS: 00000246 CPU: 0 [ 37.263266] EIP is at vprintk_emit+0xab2/0xb5c [ 37.263266] EIP is at vprintk_emit+0xab2/0xb5c [ 37.263271] EAX: 00000246 EBX: 0000002d ECX: 00000006 EDX: cac293c8 [ 37.263271] EAX: 00000246 EBX: 0000002d ECX: 00000006 EDX: cac293c8 [ 37.263277] ESI: c2aacbc2 EDI: 00000006 EBP: cac2be38 ESP: cac2be1c [ 37.263277] ESI: c2aacbc2 EDI: 00000006 EBP: cac2be38 ESP: cac2be1c [ 37.263282] DS: 007b ES: 007b FS: 0000 GS: 0000 SS: 0068 [ 37.263282] DS: 007b ES: 007b FS: 0000 GS: 0000 SS: 0068 [ 37.263288] CR0: 8005003b CR2: 00000000 CR3: 0222e000 CR4: 000006b0 [ 37.263288] CR0: 8005003b CR2: 00000000 CR3: 0222e000 CR4: 000006b0 [ 37.263296] Stack: [ 37.263296] Stack: [ 37.263314] fffffffe 00c2be30 00000246 00000000 ffffffed 00000006 00000000 cac2be58 [ 37.263314] fffffffe 00c2be30 00000246 00000000 ffffffed 00000006 00000000 cac2be58 [ 37.263331] c11b1168 00000000 00000003 00000000 00000000 c1ceb47f cac2be6c cac2be60 [ 37.263331] c11b1168 00000000 00000003 00000000 00000000 c1ceb47f cac2be6c cac2be60 [ 37.263348] c12b8713 cac2be94 c197ce8b c1ceb47f c1b14d24 00000006 00000000 c1ceabd9 [ 37.263348] c12b8713 cac2be94 c197ce8b c1ceb47f c1b14d24 00000006 00000000 c1ceabd9 [ 37.263351] Call Trace: [ 37.263351] Call Trace: [ 37.263363] [] vprintk_default+0x20/0x30 [ 37.263363] [] vprintk_default+0x20/0x30 [ 37.263372] [] printk+0x1f/0x2f [ 37.263372] [] printk+0x1f/0x2f [ 37.263382] [] of_overlay_destroy+0x1b4/0x595 [ 37.263382] [] of_overlay_destroy+0x1b4/0x595 [ 37.263392] [] of_unittest+0x252c/0x26e5 [ 37.263392] [] of_unittest+0x252c/0x26e5 [ 37.263400] [] ? slob_free+0x98c/0x9a2 [ 37.263400] [] ? slob_free+0x98c/0x9a2 [ 37.263408] [] ? __phys_addr+0x146/0x188 [ 37.263408] [] ? __phys_addr+0x146/0x188 [ 37.263414] [] ? kfree+0x11f/0x1cc [ 37.263414] [] ? kfree+0x11f/0x1cc [ 37.263423] [] do_one_initcall+0x2ee/0x474 [ 37.263423] [] do_one_initcall+0x2ee/0x474 [ 37.263432] [] ? repair_env_string+0x36/0x140 [ 37.263432] [] ? repair_env_string+0x36/0x140 [ 37.263440] [] ? of_unittest_find_node_by_name+0x11f0/0x11f0 [ 37.263440] [] ? of_unittest_find_node_by_name+0x11f0/0x11f0 [ 37.263450] [] ? parse_args+0x828/0x9c2 [ 37.263450] [] ? parse_args+0x828/0x9c2 [ 37.263461] [] ? kernel_init_freeable+0x322/0x581 [ 37.263461] [] ? kernel_init_freeable+0x322/0x581 [ 37.263470] [] kernel_init_freeable+0x416/0x581 [ 37.263470] [] kernel_init_freeable+0x416/0x581 [ 37.263480] [] kernel_init+0x16/0x1e7 [ 37.263480] [] kernel_init+0x16/0x1e7 [ 37.263488] [] ret_from_kernel_thread+0x20/0x40 [ 37.263488] [] ret_from_kernel_thread+0x20/0x40 [ 37.263496] [] ? rest_init+0x2bb/0x2bb [ 37.263496] [] ? rest_init+0x2bb/0x2bb [ 37.263609] Code: 83 05 48 90 aa c2 01 b8 a0 65 f0 c1 83 15 4c 90 aa c2 00 e9 84 f6 ff ff 83 05 40 90 aa c2 01 8b 45 ec 83 15 44 90 aa c2 00 50 9d <8d> 74 26 00 83 05 50 90 aa c2 01 83 15 54 90 aa c2 00 80 7d eb [ 37.263609] Code: 83 05 48 90 aa c2 01 b8 a0 65 f0 c1 83 15 4c 90 aa c2 00 e9 84 f6 ff ff 83 05 40 90 aa c2 01 8b 45 ec 83 15 44 90 aa c2 00 50 9d <8d> 74 26 00 83 05 50 90 aa c2 01 83 15 54 90 aa c2 00 80 7d eb [ 37.263614] Kernel panic - not syncing: softlockup: hung tasks [ 37.263614] Kernel panic - not syncing: softlockup: hung tasks Thanks, Ying Huang