FYI, we noticed the following commit (built with gcc-7):

commit: 3cd2e64830059791297a2f7817b41557a60f9234 ("drm/ttm: move ttm_lock and ttm_object into vmwgfx")
url: https://github.com/0day-ci/linux/commits/Christian-K-nig/drm-ttm-move-ttm_lock-and-ttm_object-into-vmwgfx/20180204-085007
base: git://people.freedesktop.org/~airlied/linux.git drm-next

in testcase: boot

on test machine: qemu-system-x86_64 -enable-kvm -m 512M

caused below changes (please refer to attached dmesg/kmsg for entire log/backtrace):


+-----------------------------------------------------------------------------------------------+------------+------------+
|                                                                                               | 24b8ef699e | 3cd2e64830 |
+-----------------------------------------------------------------------------------------------+------------+------------+
| boot_successes                                                                                | 18         | 0          |
| boot_failures                                                                                 | 30         | 9          |
| INFO:task_blocked_for_more_than#seconds                                                       | 16         |            |
| Kernel_panic-not_syncing:hung_task:blocked_tasks                                              | 16         |            |
| BUG:workqueue_lockup-pool                                                                     | 14         |            |
| BUG:kernel_hang_in_early-boot_stage,last_printk:early_console_in_setup_code                   | 0          | 7          |
| BUG:kernel_reboot-without-warning_in_early-boot_stage,last_printk:early_console_in_setup_code | 0          | 2          |
+-----------------------------------------------------------------------------------------------+------------+------------+



early console in setup code
BUG: kernel hang in early-boot stage, last printk: early console in setup code
Linux version 4.15.0-rc8-01510-g3cd2e64 #1
Command line: ip=::::vm-lkp-nex04-yocto-x86_64-29::dhcp root=/dev/ram0 user=lkp job=/lkp/scheduled/vm-lkp-nex04-yocto-x86_64-29/boot-1-yocto-minimal-x86_64-2016-04-22.cgz-3cd2e64830059791297a2f7817b41557a60f9234-20180217-52809-f8gx9u-0.yaml ARCH=x86_64 kconfig=x86_64-randconfig-ws0-02131753 branch=linux-devel/devel-hourly-2018021313 commit=3cd2e64830059791297a2f7817b41557a60f9234 BOOT_IMAGE=/pkg/linux/x86_64-randconfig-ws0-02131753/gcc-7/3cd2e64830059791297a2f7817b41557a60f9234/vmlinuz-4.15.0-rc8-01510-g3cd2e64 max_uptime=600 RESULT_ROOT=/result/boot/1/vm-lkp-nex04-yocto-x86_64/yocto-minimal-x86_64-2016-04-22.cgz/x86_64-randconfig-ws0-02131753/gcc-7/3cd2e64830059791297a2f7817b41557a60f9234/0 LKP_SERVER=inn debug apic=debug sysrq_always_enabled rcupdate.rcu_cpu_stall_timeout=100 net.ifnames=0 printk.devkmsg=on panic=-1 softlockup_panic=1 nmi_watchdog=panic oops=panic load_ramdisk=2 prompt_ramdisk=0 drbd.minor_count=8 systemd.log_level=err ignore_loglevel console=tty0 earlyprintk=ttyS0,115200 console=ttyS0,115200 vga=normal rw drbd.minor_count=8 rcuperf.shutdown=0

Elapsed time: 320



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,
lkp