FYI, we noticed the below changes on
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
commit db1003a719d75cebe5843a7906c02c29bec9922c ("x86/numachip: Cleanup Numachip support")
Elapsed time: 210
BUG: kernel early-boot hang
Linux version 4.3.0-rc2-00001-gdb1003a #1
Command line: root=/dev/ram0 user=lkp job=/lkp/scheduled/vm-intel12-yocto-x86_64-14/bisect_boot-1-yocto-minimal-x86_64.cgz-x86_64-allyesdebian-db1003a719d75cebe5843a7906c02c29bec9922c-20151107-100037-1jb4qfh-1.yaml ARCH=x86_64 kconfig=x86_64-allyesdebian branch=sergeh-security/2015-11-05/cgroupns commit=db1003a719d75cebe5843a7906c02c29bec9922c BOOT_IMAGE=/pkg/linux/x86_64-allyesdebian/gcc-5/db1003a719d75cebe5843a7906c02c29bec9922c/vmlinuz-4.3.0-rc2-00001-gdb1003a max_uptime=600 RESULT_ROOT=/result/boot/1/vm-intel12-yocto-x86_64/yocto-minimal-x86_64.cgz/x86_64-allyesdebian/gcc-5/db1003a719d75cebe5843a7906c02c29bec9922c/0 LKP_SERVER=inn earlyprintk=ttyS0,115200 systemd.log_level=err debug apic=debug sysrq_always_enabled rcupdate.rcu_cpu_stall_timeout=100 panic=-1 softlockup_panic=1 nmi_watchdog=panic oops=panic load_ramdisk=2 prompt_ramdisk=0 console=ttyS0,115200 console=tty0 vga=normal rw ip=::::vm-intel12-yocto-x86_64-14::dhcp drbd.minor_count=8
qemu-system-x86_64 -enable-kvm -cpu Nehalem -kernel /pkg/linux/x86_64-allyesdebian/gcc-5/db1003a719d75cebe5843a7906c02c29bec9922c/vmlinuz-4.3.0-rc2-00001-gdb1003a -append 'root=/dev/ram0 user=lkp job=/lkp/scheduled/vm-intel12-yocto-x86_64-14/bisect_boot-1-yocto-minimal-x86_64.cgz-x86_64-allyesdebian-db1003a719d75cebe5843a7906c02c29bec9922c-20151107-100037-1jb4qfh-1.yaml ARCH=x86_64 kconfig=x86_64-allyesdebian branch=sergeh-security/2015-11-05/cgroupns commit=db1003a719d75cebe5843a7906c02c29bec9922c BOOT_IMAGE=/pkg/linux/x86_64-allyesdebian/gcc-5/db1003a719d75cebe5843a7906c02c29bec9922c/vmlinuz-4.3.0-rc2-00001-gdb1003a max_uptime=600 RESULT_ROOT=/result/boot/1/vm-intel12-yocto-x86_64/yocto-minimal-x86_64.cgz/x86_64-allyesdebian/gcc-5/db1003a719d75cebe5843a7906c02c29bec9922c/0 LKP_SERVER=inn earlyprintk=ttyS0,115200 systemd.log_level=err debug apic=debug sysrq_always_enabled rcupdate.rcu_cpu_stall_timeout=100 panic=-1 softlockup_panic=1 nmi_watchdog=panic oops=panic load_ramdisk=2 prompt_ramdisk=0 console=ttyS0,115200 console=tty0 vga=normal rw ip=::::vm-intel12-yocto-x86_64-14::dhcp drbd.minor_count=8' -initrd /fs/KVM/initrd-vm-intel12-yocto-x86_64-14 -m 832 -smp 2 -device e1000,netdev=net0 -netdev user,id=net0 -boot order=nc -no-reboot -watchdog i6300esb -rtc base=localtime -drive file=/fs/KVM/disk0-vm-intel12-yocto-x86_64-14,media=disk,if=virtio -drive file=/fs/KVM/disk1-vm-intel12-yocto-x86_64-14,media=disk,if=virtio -pidfile /dev/shm/kboot/pid-vm-intel12-yocto-x86_64-14 -serial file:/dev/shm/kboot/serial-vm-intel12-yocto-x86_64-14 -daemonize -display none -monitor null