FYI, we noticed the following commit: commit: 587d8cb3f3ef434ffef664d41b4aec6d51b5f25e ("origin") git://git.cmpxchg.org/linux-mmotm.git master in testcase: boot on test machine: qemu-system-x86_64 -m 420M caused below changes (please refer to attached dmesg/kmsg for entire log/backtrace): +--------------------------------------------------+-------+------------+ | | v4.10 | 587d8cb3f3 | +--------------------------------------------------+-------+------------+ | boot_successes | 130 | 2 | | boot_failures | 27 | 10 | | BUG:kernel_hang_in_test_stage | 27 | 2 | | WARNING:at_kernel/sched/sched.h:#set_next_entity | 0 | 2 | | INFO:task_blocked_for_more_than#seconds | 0 | 8 | +--------------------------------------------------+-------+------------+ [ 387.054655] INFO: task swapper/0:1 blocked for more than 120 seconds. [ 387.058979] Not tainted 4.10.0-00001-g587d8cb #1 [ 387.061858] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 387.065680] swapper/0 D 0 1 0 0x00000000 [ 387.071338] Call Trace: [ 387.076555] __schedule+0x467/0x5b0 [ 387.082068] ? wait_for_completion+0xc3/0x170 [ 387.085149] schedule+0x23/0x40 [ 387.087783] schedule_timeout+0x36/0x2c0 [ 387.089980] ? wait_for_completion+0xc3/0x170 [ 387.092996] wait_for_completion+0xe2/0x170 [ 387.095632] ? do_task_dead+0x40/0x40 [ 387.098293] kthread_stop+0x5b/0x90 [ 387.103222] test_rht_init+0x9a3/0xa4d [ 387.106116] ? test_fw_misc_read+0x80/0x80 [ 387.109106] ? test_fw_misc_read+0x80/0x80 [ 387.112127] ? test_kstrtox_init+0xbef/0xbef [ 387.114836] ? do_early_param+0xc0/0xc0 [ 387.117657] do_one_initcall+0xb1/0x1a3 [ 387.119701] ? do_early_param+0xc0/0xc0 [ 387.122227] kernel_init_freeable+0x157/0x213 [ 387.125281] ? rest_init+0xd0/0xd0 [ 387.127816] kernel_init+0x13/0x160 [ 387.128661] ? schedule_tail+0xa/0x70 [ 387.129511] ? rest_init+0xd0/0xd0 [ 387.131809] ret_from_fork+0x2c/0x40 [ 387.134410] [ 387.134410] Showing all locks held in the system: [ 387.138337] 2 locks held by khungtaskd/15: [ 387.140952] #0: (rcu_read_lock){......}, at: [<ffffffff81151dbb>] watchdog+0xab/0x430 [ 387.147767] #1: (tasklist_lock){......}, at: [<ffffffff810f2e7a>] debug_show_all_locks+0x4a/0x170 [ 387.153490] [ 387.154448] ============================================= [ 387.154448] [ 411.030238] Writes: Total: 2 Max/Min: 0/0 Fail: 0 [ 472.808664] Writes: Total: 2 Max/Min: 0/0 Fail: 0 [ 510.670993] INFO: task swapper/0:1 blocked for more than 120 seconds. [ 510.672874] Not tainted 4.10.0-00001-g587d8cb #1 [ 510.675039] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 510.677806] swapper/0 D 0 1 0 0x00000000 [ 510.683062] Call Trace: [ 510.685057] __schedule+0x467/0x5b0 [ 510.686607] ? wait_for_completion+0xc3/0x170 [ 510.688798] schedule+0x23/0x40 [ 510.691131] schedule_timeout+0x36/0x2c0 [ 510.692708] ? wait_for_completion+0xc3/0x170 [ 510.695277] wait_for_completion+0xe2/0x170 [ 510.697628] ? do_task_dead+0x40/0x40 [ 510.698845] kthread_stop+0x5b/0x90 [ 510.700809] test_rht_init+0x9a3/0xa4d [ 510.702192] ? test_fw_misc_read+0x80/0x80 [ 510.704600] ? test_fw_misc_read+0x80/0x80 [ 510.706325] ? test_kstrtox_init+0xbef/0xbef [ 510.708309] ? do_early_param+0xc0/0xc0 [ 510.710639] do_one_initcall+0xb1/0x1a3 [ 510.712167] ? do_early_param+0xc0/0xc0 [ 510.714540] kernel_init_freeable+0x157/0x213 [ 510.716102] ? rest_init+0xd0/0xd0 [ 510.718414] kernel_init+0x13/0x160 [ 510.720766] ? schedule_tail+0xa/0x70 [ 510.722194] ? rest_init+0xd0/0xd0 [ 510.724145] ret_from_fork+0x2c/0x40 [ 510.725502] [ 510.725502] Showing all locks held in the system: [ 510.728390] 2 locks held by khungtaskd/15: [ 510.730331] #0: (rcu_read_lock){......}, at: [<ffffffff81151dbb>] watchdog+0xab/0x430 [ 510.733901] #1: (tasklist_lock){......}, at: [<ffffffff810f2e7a>] debug_show_all_locks+0x4a/0x170 [ 510.737548] [ 510.738272] ============================================= [ 510.738272] [ 534.696591] Writes: Total: 2 Max/Min: 0/0 Fail: 0 [ 597.345047] Writes: Total: 2 Max/Min: 0/0 Fail: 0 [ 635.385403] INFO: task swapper/0:1 blocked for more than 120 seconds. [ 635.388738] Not tainted 4.10.0-00001-g587d8cb #1 [ 635.391824] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 635.394978] swapper/0 D 0 1 0 0x00000000 [ 635.397782] Call Trace: [ 635.399326] __schedule+0x467/0x5b0 [ 635.401385] ? wait_for_completion+0xc3/0x170 [ 635.403704] schedule+0x23/0x40 [ 635.405043] schedule_timeout+0x36/0x2c0 [ 635.406913] ? wait_for_completion+0xc3/0x170 [ 635.408491] wait_for_completion+0xe2/0x170 [ 635.410835] ? do_task_dead+0x40/0x40 [ 635.412481] kthread_stop+0x5b/0x90 [ 635.414456] test_rht_init+0x9a3/0xa4d [ 635.416014] ? test_fw_misc_read+0x80/0x80 [ 635.418378] ? test_fw_misc_read+0x80/0x80 [ 635.420652] ? test_kstrtox_init+0xbef/0xbef [ 635.422414] ? do_early_param+0xc0/0xc0 [ 635.424275] do_one_initcall+0xb1/0x1a3 [ 635.425114] ? do_early_param+0xc0/0xc0 [ 635.427380] kernel_init_freeable+0x157/0x213 [ 635.428903] ? rest_init+0xd0/0xd0 [ 635.430872] kernel_init+0x13/0x160 [ 635.432248] ? schedule_tail+0xa/0x70 [ 635.434390] ? rest_init+0xd0/0xd0 [ 635.435871] ret_from_fork+0x2c/0x40 [ 635.437616] [ 635.437616] Showing all locks held in the system: [ 635.440310] 2 locks held by khungtaskd/15: [ 635.441391] #0: (rcu_read_lock){......}, at: [<ffffffff81151dbb>] watchdog+0xab/0x430 [ 635.445149] #1: (tasklist_lock){......}, at: [<ffffffff810f2e7a>] debug_show_all_locks+0x4a/0x170 [ 635.449786] [ 635.450686] ============================================= [ 635.450686] [ 659.388636] Writes: Total: 2 Max/Min: 0/0 Fail: 0 [ 712.525992] Started 10 threads, 0 failed [ 712.895819] test_printf: all 260 tests passed [ 723.889084] test_bitmap: all 460506 tests passed [ 723.904010] Writes: Total: 2 Max/Min: 0/0 Fail: 0 [ 723.910452] test_uuid: all 18 tests passed [ 724.006454] gpio_it87: no device [ 724.039886] gpio-mockup: probe of gpio-mockup failed with error -22 [ 724.098935] no IO addresses supplied [ 724.119040] hgafb: HGA card not detected. [ 724.122365] hgafb: probe of hgafb.0 failed with error -22 [ 724.150106] ipmi message handler version 39.2 [ 724.157376] IPMI System Interface driver. [ 724.180895] ipmi_si: Unable to find any System Interface(s) [ 724.184601] IPMI SSIF Interface driver [ 724.190290] Copyright (C) 2004 MontaVista Software - IPMI Powerdown via sys_reboot. [ 724.253173] input: Power Button as /devices/LNXSYSTM:00/LNXPWRBN:00/input/input0 [ 724.264153] ACPI: Power Button [PWRF] [ 735.148537] Serial: 8250/16550 driver, 4 ports, IRQ sharing disabled [ 735.233408] 00:05: ttyS0 at I/O 0x3f8 (irq = 4, base_baud = 115200) is a 16550A [ 735.318570] 00:06: ttyS1 at I/O 0x2f8 (irq = 3, base_baud = 115200) is a 16550A [ 735.473197] Non-volatile memory driver v1.3 [ 735.477446] telclk_interrupt = 0xf non-mcpbl0010 hw. [ 735.591245] [drm] Initialized vgem 1.0.0 20120112 for virtual device on minor 0 [ 735.647256] dummy-irq: no IRQ given. Use irq=N [ 735.681466] Silicon Labs C2 port support v. 0.51.0 - (C) 2007 Rodolfo Giometti [ 735.845111] mtdoops: mtd device (mtddev=name/number) must be supplied [ 735.852134] L440GX flash mapping: failed to find PIIX4 ISA bridge, cannot continue [ 735.865130] platform physmap-flash.0: failed to claim resource 0: [mem 0x08000000-0x07ffffff] [ 735.883915] slram: not enough parameters. [ 735.906143] [nandsim] warning: read_byte: unexpected data output cycle, state is STATE_READY return 0x0 [ 735.910923] [nandsim] warning: read_byte: unexpected data output cycle, state is STATE_READY return 0x0 [ 735.914294] [nandsim] warning: read_byte: unexpected data output cycle, state is STATE_READY return 0x0 [ 735.920410] [nandsim] warning: read_byte: unexpected data output cycle, state is STATE_READY return 0x0 [ 735.924747] [nandsim] warning: read_byte: unexpected data output cycle, state is STATE_READY return 0x0 [ 735.928433] [nandsim] warning: read_byte: unexpected data output cycle, state is STATE_READY return 0x0 [ 735.934722] nand: device found, Manufacturer ID: 0x98, Chip ID: 0x39 [ 735.939095] nand: Toshiba NAND 128MiB 1,8V 8-bit [ 735.942106] nand: 128 MiB, SLC, erase size: 16 KiB, page size: 512, OOB size: 16 [ 735.957834] flash size: 128 MiB [ 735.959474] page size: 512 bytes [ 735.962273] OOB area size: 16 bytes [ 735.965417] sector size: 16 KiB [ 735.967643] pages number: 262144 [ 735.968971] pages per sector: 32 [ 735.970917] bus width: 8 [ 735.972120] bits in sector size: 14 [ 735.974139] bits in page size: 9 [ 735.975415] bits in OOB size: 4 [ 735.978300] flash size with OOB: 135168 KiB [ 735.981223] page address bytes: 4 [ 735.983293] sector address bytes: 3 [ 735.984747] options: 0x42 [ 736.221861] Scanning device for bad blocks [ 742.975687] Creating 1 MTD partitions on "NAND 128MiB 1,8V 8-bit": [ 742.980464] 0x000000000000-0x000008000000 : "NAND simulator partition 0" [ 743.824508] Ethernet Channel Bonding Driver: v3.7.1 (April 27, 2011) [ 744.242711] eql: Equalizer2002: Simon Janes (simon(a)ncm.com) and David S. Miller (davem(a)redhat.com) [ 744.712427] libphy: Fixed MDIO Bus: probed [ 745.071870] tun: Universal TUN/TAP device driver, 1.6 [ 745.074268] tun: (C) 1999-2004 Max Krasnyansky <maxk(a)qualcomm.com&gt; [ 745.108362] vcan: Virtual CAN interface driver [ 745.131637] e1000: Intel(R) PRO/1000 Network Driver - version 7.3.21-k8-NAPI [ 745.134857] e1000: Copyright (c) 1999-2006 Intel Corporation. [ 780.054307] ACPI: PCI Interrupt Link [LNKC] enabled at IRQ 11 [ 780.961663] e1000 0000:00:03.0 eth0: (PCI:33MHz:32-bit) 52:54:00:12:34:56 [ 780.969734] e1000 0000:00:03.0 eth0: Intel(R) PRO/1000 Network Connection To reproduce: git clone git://git.kernel.org/pub/scm/linux/kernel/git/wfg/lkp-tests.git cd lkp-tests bin/lkp qemu -k <bzImage> job-script # job-script is attached in this email Thanks, Kernel Test Robot