FYI, we noticed the below changes on https://github.com/0day-ci/linux Zhaoyang-Huang/rpm-refining-the-rpm_suspend-function/20160120-160501 commit 1b018e075699994eb530a5f19f1acab2a926f84b ("rpm: refining the rpm_suspend function") +------------------------------------------------+------------+------------+ | | dc7a021ccc | 1b018e0756 | +------------------------------------------------+------------+------------+ | boot_successes | 40 | 0 | | boot_failures | 0 | 37 | | INFO:rcu_preempt_detected_stalls_on_CPUs/tasks | 0 | 13 | | BUG:kernel_boot_hang | 0 | 37 | | backtrace:schedule_timeout | 0 | 2 | +------------------------------------------------+------------+------------+ [ 6.040069] usb usb1: SerialNumber: dummy_hcd.0 [ 6.041207] hub 1-0:1.0: USB hub found [ 6.041745] hub 1-0:1.0: 1 port detected [ 106.049840] INFO: rcu_preempt detected stalls on CPUs/tasks: [ 106.053605] Task dump for CPU 1: [ 106.054024] kworker/1:1 R running task 14368 29 2 0x00000000 [ 106.054968] Workqueue: pm pm_runtime_work [ 106.055509] ffffffff8348aec8 ffffffff82d568f0 0000000000000000 ffffffff822b037b [ 106.056527] 0000000000000001 0000000000000000 ffff8800121029c0 ffff880012bd50c0 [ 106.057553] ffff88001211c440 ffff88001211c440 ffff8800121029f0 ffff880012153e48 [ 106.058570] Call Trace: [ 106.058897] [] ? worker_thread+0x28c/0x37e [ 106.059640] [] ? process_scheduled_works+0x2e/0x2e [ 106.060467] [] ? kthread+0xf6/0xfe [ 106.061117] [] ? __kthread_parkme+0x82/0x82 [ 106.061869] [] ? ret_from_fork+0x3f/0x70 [ 106.062589] [] ? __kthread_parkme+0x82/0x82 [ 106.063337] rcu_preempt kthread starved for 25002 jiffies! g18446744073709551426 c18446744073709551425 f0x0 RCU_GP_WAIT_FQS(3) ->state=0x1 [ 106.064918] rcu_preempt S ffff88000012fd08 14696 7 2 0x00000000 [ 106.065868] ffff88000012fd08 ffff880000068000 ffff8800001216c0 ffff880000130000 [ 106.066886] ffff880012bcd980 ffff88000012fd40 ffff8800001216c0 0000000000000001 [ 106.067911] ffff88000012fd20 ffffffff81c4d5d7 00000000fffee08c ffff88000012fdc0 [ 106.068923] Call Trace: [ 106.069247] [] schedule+0x83/0x98 [ 106.069890] [] schedule_timeout+0x144/0x173 [ 106.070645] [] ? cascade+0x47/0x47 [ 106.071299] [] rcu_gp_kthread+0x574/0x8d7 [ 106.072033] [] ? rcu_gp_kthread+0x574/0x8d7 [ 106.072787] [] ? __wake_up_common+0x7c/0x7c [ 106.073537] [] ? force_qs_rnp+0x164/0x164 [ 106.074261] [] kthread+0xf6/0xfe [ 106.074895] [] ? __kthread_parkme+0x82/0x82 [ 106.075645] [] ret_from_fork+0x3f/0x70 [ 106.076337] [] ? __kthread_parkme+0x82/0x82 [ 406.069839] INFO: rcu_preempt detected stalls on CPUs/tasks: [ 406.073733] Task dump for CPU 1: [ 406.074151] kworker/1:1 R running task 14368 29 2 0x00000000 [ 406.075103] Workqueue: pm pm_runtime_work [ 406.075641] ffffffff8348aec8 ffffffff82d568f0 0000000000000000 ffffffff822b037b [ 406.076652] 0000000000000001 0000000000000000 ffff8800121029c0 ffff880012bd50c0 [ 406.077674] ffff88001211c440 ffff88001211c440 ffff8800121029f0 ffff880012153e48 [ 406.078677] Call Trace: [ 406.079001] [] ? worker_thread+0x28c/0x37e [ 406.079741] [] ? process_scheduled_works+0x2e/0x2e [ 406.080565] [] ? kthread+0xf6/0xfe [ 406.081710] [] ? __kthread_parkme+0x82/0x82 [ 406.082449] [] ? ret_from_fork+0x3f/0x70 [ 406.083162] [] ? __kthread_parkme+0x82/0x82 [ 406.083914] rcu_preempt kthread starved for 100007 jiffies! g18446744073709551426 c18446744073709551425 f0x2 RCU_GP_WAIT_FQS(3) ->state=0x100 [ 406.085516] rcu_preempt W ffff88000012fd08 14696 7 2 0x00000000 [ 406.086455] ffff88000012fd08 ffff880000068000 ffff8800001216c0 ffff880000130000 [ 406.087461] ffff880012bcd980 ffff88000012fd40 ffff8800001216c0 0000000000000001 [ 406.088471] ffff88000012fd20 ffffffff81c4d5d7 00000000fffee08c ffff88000012fdc0 [ 406.089480] Call Trace: [ 406.089804] [] schedule+0x83/0x98 [ 406.090435] [] schedule_timeout+0x144/0x173 [ 406.091180] [] ? cascade+0x47/0x47 [ 406.091832] [] rcu_gp_kthread+0x574/0x8d7 [ 406.092558] [] ? rcu_gp_kthread+0x574/0x8d7 [ 406.093300] [] ? __wake_up_common+0x7c/0x7c [ 406.094047] [] ? force_qs_rnp+0x164/0x164 [ 406.094779] [] kthread+0xf6/0xfe [ 406.095398] [] ? __kthread_parkme+0x82/0x82 [ 406.096144] [] ret_from_fork+0x3f/0x70 [ 406.096834] [] ? __kthread_parkme+0x82/0x82 Elapsed time: 440 BUG: kernel boot hang qemu-system-x86_64 -enable-kvm -cpu Nehalem -kernel /pkg/linux/x86_64-acpi-redef/gcc-5/1b018e075699994eb530a5f19f1acab2a926f84b/vmlinuz-4.4.0-03451-g1b018e0 -append 'root=/dev/ram0 user=lkp job=/lkp/scheduled/vm-intel12-yocto-x86_64-7/bisect_boot-1-yocto-minimal-x86_64.cgz-x86_64-acpi-redef-1b018e075699994eb530a5f19f1acab2a926f84b-20160121-24106-uy1lg5-0.yaml ARCH=x86_64 kconfig=x86_64-acpi-redef branch=linux-devel/devel-spot-201601210155 commit=1b018e075699994eb530a5f19f1acab2a926f84b BOOT_IMAGE=/pkg/linux/x86_64-acpi-redef/gcc-5/1b018e075699994eb530a5f19f1acab2a926f84b/vmlinuz-4.4.0-03451-g1b018e0 max_uptime=600 RESULT_ROOT=/result/boot/1/vm-intel12-yocto-x86_64/yocto-minimal-x86_64.cgz/x86_64-acpi-redef/gcc-5/1b018e075699994eb530a5f19f1acab2a926f84b/3 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_64-7::dhcp drbd.minor_count=8' -initrd /fs/KVM/initrd-vm-intel12-yocto-x86_64-7 -m 320 -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_64-7,media=disk,if=virtio -drive file=/fs/KVM/disk1-vm-intel12-yocto-x86_64-7,media=disk,if=virtio -pidfile /dev/shm/kboot/pid-vm-intel12-yocto-x86_64-7 -serial file:/dev/shm/kboot/serial-vm-intel12-yocto-x86_64-7 -daemonize -display none -monitor null Thanks, Kernel Test Robot