FYI, we noticed the following commit: https://git.kernel.org/pub/scm/linux/kernel/git/kees/linux.git kaslr/highmem-relocs commit 2e1e7c3abd33d77bb8f05e57c07ac91e8436ab9b ("x86/KASLR: Add physical address randomization >4G") on test machine: vm-vp-quantal-x86_64: 2 threads qemu-system-x86_64 -enable-kvm with 360M memory caused below changes: +------------------------------------------------------------------+------------+------------+ | | cb3a00eb69 | 2e1e7c3abd | +------------------------------------------------------------------+------------+------------+ | boot_successes | 0 | 0 | | boot_failures | 8 | 10 | | BUG:kernel_test_hang | 2 | 2 | | backtrace:__ubsan_handle_type_mismatch | 8 | 2 | | backtrace:early_init_intel | 8 | 2 | | backtrace:early_cpu_init | 8 | 2 | | backtrace:check_mpx_erratum | 8 | 2 | | backtrace:fpu__init_cpu_xstate | 8 | 2 | | backtrace:fpu__init_cpu | 8 | 2 | | backtrace:fpu__init_system | 8 | 2 | | backtrace:fpu__init_system_xstate | 8 | 2 | | backtrace:vmware_platform | 8 | 2 | | backtrace:init_hypervisor_platform | 8 | 2 | | backtrace:ms_hyperv_platform | 8 | 2 | | backtrace:kvm_detect | 8 | 2 | | backtrace:mtrr_bp_init | 8 | 2 | | backtrace:prepare_set | 8 | 2 | | backtrace:mtrr_bp_pat_init | 8 | 2 | | backtrace:pat_init | 8 | 2 | | backtrace:post_set | 8 | 2 | | backtrace:init_mem_mapping | 8 | 2 | | backtrace:acpi_initialize_tables | 8 | | | backtrace:acpi_table_init | 8 | | | backtrace:acpi_boot_table_init | 8 | | | backtrace:acpi_tb_init_table_descriptor | 8 | | | backtrace:acpi_table_parse | 8 | 2 | | backtrace:early_acpi_boot_init | 8 | 2 | | backtrace:alloc_usemap_and_memmap | 8 | 2 | | backtrace:sparse_init | 8 | 2 | | backtrace:paging_init | 8 | 2 | | backtrace:acpi_boot_init | 8 | 2 | | backtrace:create_boot_cache | 8 | 2 | | backtrace:kmem_cache_init | 8 | 2 | | backtrace:arch_ioremap_pud_supported | 8 | 2 | | backtrace:ioremap_huge_init | 8 | 2 | | backtrace:arch_ioremap_pmd_supported | 8 | 2 | | backtrace:tsc_init | 8 | 2 | | backtrace:x86_late_time_init | 8 | 2 | | backtrace:unsynchronized_tsc | 8 | 2 | | backtrace:acpi_initialize_subsystem | 8 | 2 | | backtrace:acpi_early_init | 8 | 2 | | backtrace:init_intel | 8 | 2 | | backtrace:x86_init_rdrand | 8 | 2 | | backtrace:mce_available | 8 | 2 | | backtrace:mcheck_cpu_init | 8 | 2 | | backtrace:intel_pmu_init | 8 | 2 | | backtrace:init_hw_perf_events | 8 | 2 | | backtrace:kernel_init_freeable | 8 | 2 | | backtrace:set_real_mode_permissions | 8 | 2 | | backtrace:__alloc_workqueue_key | 8 | 2 | | backtrace:init_workqueues | 8 | 2 | | backtrace:APIC_init_uniprocessor | 8 | 2 | | backtrace:up_late_init | 8 | 2 | | backtrace:apic_bsp_setup | 8 | 2 | | backtrace:cpuset_init_smp | 8 | 2 | | backtrace:do_mount | 8 | 2 | | backtrace:SyS_mount | 8 | 2 | | backtrace:devtmpfsd | 8 | 2 | | backtrace:init_lapic_sysfs | 8 | 2 | | backtrace:calibrate_xor_blocks | 8 | 2 | | backtrace:bts_init | 8 | 2 | | backtrace:pt_init | 8 | 2 | | backtrace:mtrr_if_init | 8 | 2 | | backtrace:default_bdi_init | 8 | 2 | | backtrace:raid#_select_algo | 8 | 2 | | backtrace:acpi_load_tables | 8 | 2 | | backtrace:acpi_init | 8 | 2 | | backtrace:acpi_initialize_objects | 8 | 2 | | backtrace:acpi_early_processor_osc | 8 | 2 | | backtrace:acpi_get_table | 8 | | | backtrace:acpi_table_attr_init | 8 | | | backtrace:acpi_sysfs_init | 8 | | | backtrace:acpi_get_cpuid | 8 | 2 | | backtrace:early_init_pdc | 8 | 2 | | backtrace:acpi_early_processor_set_pdc | 8 | 2 | | backtrace:acpi_processor_set_pdc | 8 | 2 | | backtrace:acpi_bus_scan | 8 | 2 | | backtrace:acpi_scan_init | 8 | 2 | | backtrace:register_netdev | 8 | 2 | | backtrace:loopback_net_init | 8 | 2 | | backtrace:ops_init | 8 | 2 | | backtrace:register_pernet_device | 8 | 2 | | backtrace:net_dev_init | 8 | 2 | | backtrace:hpet_msi_capability_lookup | 8 | 2 | | backtrace:hpet_late_init | 8 | 2 | | backtrace:hpet_work | 8 | | | backtrace:tick_switch_to_oneshot | 8 | | | backtrace:tick_init_highres | 8 | | | backtrace:printk | 6 | | | backtrace:dquot_init | 6 | | | backtrace:acpi_get_devices | 8 | 2 | | backtrace:pnpacpi_init | 8 | 2 | | backtrace:populate_rootfs | 8 | 2 | | backtrace:vfs_symlink | 8 | 2 | | backtrace:SyS_symlinkat | 8 | 2 | | backtrace:SyS_symlink | 8 | 2 | | backtrace:do_sys_open | 2 | 2 | | backtrace:SyS_open | 2 | 2 | | backtrace:amd_ibs_init | 2 | 2 | | backtrace:msr_init | 2 | 2 | | backtrace:test_aperfmperf | 2 | 2 | | backtrace:test_ptsc | 2 | 2 | | backtrace:test_irperf | 2 | 2 | | backtrace:intel_uncore_init | 2 | 2 | | backtrace:cstate_pmu_init | 2 | 2 | | backtrace:init_tsc_clocksource | 2 | 2 | | backtrace:cryptomgr_test | 2 | 2 | | backtrace:chacha20_simd_mod_init | 2 | 2 | | backtrace:sha256_ssse3_mod_init | 2 | 2 | | backtrace:avx_usable | 2 | | | backtrace:sha512_ssse3_mod_init | 2 | 2 | | backtrace:camellia_aesni_init | 2 | 2 | | backtrace:tsc_refine_calibration_work | 2 | 2 | | backtrace:__pci_register_driver | 2 | 2 | | backtrace:virtio_pci_driver_init | 2 | 2 | | backtrace:__parport_register_driver | 2 | 2 | | backtrace:ppdev_init | 2 | 2 | | backtrace:do_group_exit | 2 | 2 | | backtrace:SyS_exit_group | 2 | 2 | | backtrace:driver_register | 2 | 2 | | backtrace:ide_cdrom_init | 2 | 2 | | backtrace:sdebug_add_adapter | 2 | 2 | | backtrace:scsi_debug_init | 2 | 2 | | backtrace:print_ICs | 2 | 2 | | backtrace:deferred_probe_initcall | 2 | 2 | | backtrace:ip_auto_config | 2 | 2 | | backtrace:sock_sendmsg | 2 | 2 | | backtrace:SyS_sendto | 2 | 2 | | backtrace:vfs_write | 2 | 2 | | backtrace:SyS_write | 2 | 2 | | backtrace:css_free_work_fn | 2 | 2 | | backtrace:pwq_dec_nr_in_flight | 2 | 2 | | backtrace:vfs_read | 2 | 2 | | backtrace:SyS_read | 2 | 2 | | invoked_oom-killer:gfp_mask=0x | 6 | | | warn_alloc_failed+0x | 6 | | | Mem-Info | 6 | | | Kernel_panic-not_syncing:Out_of_memory_and_no_killable_processes | 6 | | | backtrace:init_cache_modes | 6 | | | backtrace:pat_disable | 6 | | | backtrace:vfs_lstat | 1 | | | backtrace:SyS_newlstat | 1 | | | backtrace:clocksource_done_booting | 2 | | | backtrace:filename_create | 2 | | | backtrace:setup_xstate_comp | 0 | 2 | | backtrace:avx2_usable | 0 | 2 | | backtrace:aesni_init | 0 | 2 | | backtrace:do_munmap | 0 | 1 | | backtrace:SyS_munmap | 0 | 1 | | System_halted | 0 | 8 | | BUG:kernel_boot_hang | 0 | 8 | +------------------------------------------------------------------+------------+------------+ Compressed data violation -- System halted Elapsed time: 440 BUG: kernel boot hang Linux version 4.7.0-rc1-00126-g2e1e7c3 #1 Command line: root=/dev/ram0 user=lkp job=/lkp/scheduled/vm-vp-quantal-x86_64-25/bisect_boot-1-quantal-core-x86_64.cgz-x86_64-randconfig-v0-06040910-2e1e7c3abd33d77bb8f05e57c07ac91e8436ab9b-20160605-130167-h3dynt-0.yaml ARCH=x86_64 kconfig=x86_64-randconfig-v0-06040910 branch=linux-devel/devel-spot-201606040735 commit=2e1e7c3abd33d77bb8f05e57c07ac91e8436ab9b BOOT_IMAGE=/pkg/linux/x86_64-randconfig-v0-06040910/gcc-6/2e1e7c3abd33d77bb8f05e57c07ac91e8436ab9b/vmlinuz-4.7.0-rc1-00126-g2e1e7c3 max_uptime=600 RESULT_ROOT=/result/boot/1/vm-vp-quantal-x86_64/quantal-core-x86_64.cgz/x86_64-randconfig-v0-06040910/gcc-6/2e1e7c3abd33d77bb8f05e57c07ac91e8436ab9b/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_64-25::dhcp drbd.minor_count=8 qemu-system-x86_64 -enable-kvm -kernel /pkg/linux/x86_64-randconfig-v0-06040910/gcc-6/2e1e7c3abd33d77bb8f05e57c07ac91e8436ab9b/vmlinuz-4.7.0-rc1-00126-g2e1e7c3 -append 'root=/dev/ram0 user=lkp job=/lkp/scheduled/vm-vp-quantal-x86_64-25/bisect_boot-1-quantal-core-x86_64.cgz-x86_64-randconfig-v0-06040910-2e1e7c3abd33d77bb8f05e57c07ac91e8436ab9b-20160605-130167-h3dynt-0.yaml ARCH=x86_64 kconfig=x86_64-randconfig-v0-06040910 branch=linux-devel/devel-spot-201606040735 commit=2e1e7c3abd33d77bb8f05e57c07ac91e8436ab9b BOOT_IMAGE=/pkg/linux/x86_64-randconfig-v0-06040910/gcc-6/2e1e7c3abd33d77bb8f05e57c07ac91e8436ab9b/vmlinuz-4.7.0-rc1-00126-g2e1e7c3 max_uptime=600 RESULT_ROOT=/result/boot/1/vm-vp-quantal-x86_64/quantal-core-x86_64.cgz/x86_64-randconfig-v0-06040910/gcc-6/2e1e7c3abd33d77bb8f05e57c07ac91e8436ab9b/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_64-25::dhcp drbd.minor_count=8' -initrd /fs/sdc1/initrd-vm-vp-quantal-x86_64-25 -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_64-25 -serial file:/dev/shm/kboot/serial-vm-vp-quantal-x86_64-25 -daemonize -display none -monitor null FYI, raw QEMU command line is: qemu-system-x86_64 -enable-kvm -kernel /pkg/linux/x86_64-randconfig-v0-06040910/gcc-6/2e1e7c3abd33d77bb8f05e57c07ac91e8436ab9b/vmlinuz-4.7.0-rc1-00126-g2e1e7c3 -append 'root=/dev/ram0 user=lkp job=/lkp/scheduled/vm-vp-quantal-x86_64-25/bisect_boot-1-quantal-core-x86_64.cgz-x86_64-randconfig-v0-06040910-2e1e7c3abd33d77bb8f05e57c07ac91e8436ab9b-20160605-130167-h3dynt-0.yaml ARCH=x86_64 kconfig=x86_64-randconfig-v0-06040910 branch=linux-devel/devel-spot-201606040735 commit=2e1e7c3abd33d77bb8f05e57c07ac91e8436ab9b BOOT_IMAGE=/pkg/linux/x86_64-randconfig-v0-06040910/gcc-6/2e1e7c3abd33d77bb8f05e57c07ac91e8436ab9b/vmlinuz-4.7.0-rc1-00126-g2e1e7c3 max_uptime=600 RESULT_ROOT=/result/boot/1/vm-vp-quantal-x86_64/quantal-core-x86_64.cgz/x86_64-randconfig-v0-06040910/gcc-6/2e1e7c3abd33d77bb8f05e57c07ac91e8436ab9b/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_64-25::dhcp drbd.minor_count=8' -initrd /fs/sdc1/initrd-vm-vp-quantal-x86_64-25 -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_64-25 -serial file:/dev/shm/kboot/serial-vm-vp-quantal-x86_64-25 -daemonize -display none -monitor null Thanks, Xiaolong