FYI, we noticed the following commit: https://github.com/pantoniou/linux-beagle-track-mainline.git bbb-overlays commit dda0e3dc86735058b0bd8f88c00d978257072395 ("of: unittest: Unit-tests for target root overlays.") on test machine: vm-vp-quantal-x86_64: 2 threads qemu-system-x86_64 -enable-kvm with 360M memory caused below changes: [ 8.327386] of_overlay_destroy: removal check failed for overlay #5 [ 8.327386] of_overlay_destroy: removal check failed for overlay #5 [ 8.332972] find_target_node_direct: target "/testcase-data/overlay-node/test-bus/test-unittest18" not under target_root "/testcase-data/overlay-node/test-bus/test-unittest19" [ 8.332972] find_target_node_direct: target "/testcase-data/overlay-node/test-bus/test-unittest18" not under target_root "/testcase-data/overlay-node/test-bus/test-unittest19" [ 8.335870] __of_overlay_create: of_build_overlay_info() failed for tree@/testcase-data/overlay19 [ 8.335870] __of_overlay_create: of_build_overlay_info() failed for tree@/testcase-data/overlay19 FYI, raw QEMU command line is: qemu-system-x86_64 -enable-kvm -kernel /pkg/linux/x86_64-randconfig-r0-04260040/gcc-5/dda0e3dc86735058b0bd8f88c00d978257072395/vmlinuz-4.6.0-rc4-00040-gdda0e3d -append 'root=/dev/ram0 user=lkp job=/lkp/scheduled/vm-vp-quantal-x86_64-57/bisect_boot-1-quantal-core-x86_64.cgz-x86_64-randconfig-r0-04260040-dda0e3dc86735058b0bd8f88c00d978257072395-20160426-54281-1qcjv0e-0.yaml ARCH=x86_64 kconfig=x86_64-randconfig-r0-04260040 branch=linux-devel/devel-catchup-201604260232 commit=dda0e3dc86735058b0bd8f88c00d978257072395 BOOT_IMAGE=/pkg/linux/x86_64-randconfig-r0-04260040/gcc-5/dda0e3dc86735058b0bd8f88c00d978257072395/vmlinuz-4.6.0-rc4-00040-gdda0e3d max_uptime=600 RESULT_ROOT=/result/boot/1/vm-vp-quantal-x86_64/quantal-core-x86_64.cgz/x86_64-randconfig-r0-04260040/gcc-5/dda0e3dc86735058b0bd8f88c00d978257072395/0 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-vp-quantal-x86_64-57::dhcp drbd.minor_count=8' -initrd /fs/sdh1/initrd-vm-vp-quantal-x86_64-57 -m 360 -smp 2 -device e1000,netdev=net0 -netdev user,id=net0 -boot order=nc -no-reboot -watchdog i6300esb -rtc base=localtime -pidfile /dev/shm/kboot/pid-vm-vp-quantal-x86_64-57 -serial file:/dev/shm/kboot/serial-vm-vp-quantal-x86_64-57 -daemonize -display none -monitor null Thanks, Xiaolong