Hi Jesse, 0day kernel testing robot got the below dmesg and the first bad commit is git://people.freedesktop.org/~jbarnes/linux async-fb-probe commit b739c9982801e5f76097311b67dfd76891b10988 Author: Jesse Barnes AuthorDate: Wed May 28 10:21:17 2014 -0700 Commit: Jesse Barnes CommitDate: Wed May 28 12:17:34 2014 -0700 drm: take modeset locks around initial fb helper probing Drivers ought to complain otherwise. Signed-off-by: Jesse Barnes =================================================== PARENT COMMIT NOT CLEAN. LOOK OUT FOR WRONG BISECT! =================================================== 1 /kernel/i386-randconfig-c1-06021140/071f9c57eea4876288ba1254c9ac3b0f077c2dd6 Attached dmesg for the parent commit, too, to help confirm whether it is a noise error. +-------------------------------------------------------------+------------+------------+ | | 071f9c57ee | b739c99828 | +-------------------------------------------------------------+------------+------------+ | boot_successes | 59 | 0 | | boot_failures | 1 | 20 | | WARNING:CPU:PID:at_mm/page_alloc.c:__alloc_pages_slowpath() | 1 | | | backtrace:SYSC_socketcall | 1 | | | backtrace:SyS_socketcall | 1 | | | INFO:task_blocked_for_more_than_seconds | 0 | 20 | | EIP_is_at_native_apic_mem_write | 0 | 20 | | Kernel_panic-not_syncing:hung_task:blocked_tasks | 0 | 20 | | backtrace:drm_fb_helper_initial_config | 0 | 20 | | backtrace:cirrus_fbdev_init | 0 | 20 | | backtrace:cirrus_modeset_init | 0 | 20 | | backtrace:__pci_register_driver | 0 | 20 | | backtrace:drm_pci_init | 0 | 20 | | backtrace:cirrus_init | 0 | 20 | | backtrace:kernel_init_freeable | 0 | 20 | | backtrace:watchdog | 0 | 20 | +-------------------------------------------------------------+------------+------------+ [ 8.873617] [drm] Initialized drm 1.1.0 20060810 [ 8.874286] [drm] radeon kernel modesetting enabled. [ 8.876773] [TTM] Zone kernel: Available graphics memory: 135440 kiB [ 8.877424] [TTM] Initializing pool allocator [ 61.017759] spin_lock-torture: Writes: Total: 2 Max/Min: 0/0 Fail: 0 [ 121.025590] spin_lock-torture: Writes: Total: 2 Max/Min: 0/0 Fail: 0 [ 181.030819] spin_lock-torture: Writes: Total: 2 Max/Min: 0/0 Fail: 0 [ 240.212728] INFO: task swapper:1 blocked for more than 120 seconds. [ 240.213429] Not tainted 3.15.0-rc5-00087-gb739c99 #1 [ 240.213994] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 240.214777] swapper D d3429c24 5944 1 0 0x00000000 [ 240.215484] d3429c48 00000046 00000000 d3429c24 c184af4c c2f31008 d3422000 d1f2d034 [ 240.216408] c2f31008 d1f2d034 c2f30fe0 c2f30fe0 d3429c1c c10bbfe0 d1f2d02c c2f30fe0 [ 240.217339] d3429c2c c10bc022 d1f2d02c 00000001 00000001 c10bc839 00000002 c2f30fe0 [ 240.218258] Call Trace: [ 240.218551] [] ? rb_erase+0x3d/0x576 [ 240.219043] [] ? __dequeue_entity+0x4d/0x5f [ 240.219573] [] ? set_next_entity+0x30/0x63 [ 240.220108] [] ? pick_next_task_fair+0x267/0x29a [ 240.220698] [] __schedule+0x893/0xa1b [ 240.221178] [] schedule+0x145/0x155 [ 240.221629] [] schedule_preempt_disabled+0x2a/0x4e [ 240.222220] [] mutex_lock_nested+0x470/0x8cd [ 240.222763] [] ? drm_modeset_lock_all+0x23/0x80 [ 240.223321] [] ? drm_modeset_lock_all+0x23/0x80 [ 240.223872] [] drm_modeset_lock_all+0x23/0x80 [ 240.224418] [] drm_fb_helper_initial_config+0x2d0/0x78e [ 240.225059] [] ? debug_mutex_unlock+0x31a/0x3ca [ 240.225629] [] ? _mutex_lock_nest_lock+0x797/0x8c9 [ 240.226213] [] ? __mutex_unlock_slowpath+0x2eb/0x30f [ 240.226811] [] ? drm_modeset_unlock_all+0x63/0x76 [ 240.227406] [] cirrus_fbdev_init+0xf8/0x115 [ 240.227947] [] cirrus_modeset_init+0x2ee/0x3a9 [ 240.228505] [] ? cirrus_device_init+0x153/0x1e9 [ 240.229083] [] cirrus_driver_load+0x134/0x1c3 [ 240.229633] [] drm_dev_register+0xf0/0x1f4 [ 240.230149] [] drm_get_pci_dev+0x207/0x336 [ 240.230668] [] ? cirrus_kick_out_firmware_fb+0x11c/0x137 [ 240.231312] [] ? kfree+0x14e/0x1d4 [ 240.231764] [] cirrus_pci_probe+0x4c/0x5e [ 240.232279] [] pci_device_probe+0xd0/0x1a5 [ 240.232824] [] ? sysfs_create_link+0x20/0x30 [ 240.233376] [] driver_probe_device+0x137/0x3fe [ 240.233926] [] __driver_attach+0xa0/0xf4 [ 240.234420] [] bus_for_each_dev+0x96/0xf3 [ 240.234926] [] driver_attach+0x25/0x35 [ 240.235413] [] ? driver_probe_device+0x3fe/0x3fe [ 240.235976] [] bus_add_driver+0x161/0x389 [ 240.236483] [] driver_register+0x16e/0x1f6 [ 240.237006] [] ? __raw_spin_lock_init+0x49/0x78 [ 240.237570] [] __pci_register_driver+0x61/0x72 [ 240.238129] [] drm_pci_init+0x9d/0x18c [ 240.238623] [] ? ftrace_define_fields_i915_gem_object_create+0xa9/0xa9 [ 240.239367] [] cirrus_init+0x37/0x4f [ 240.239838] [] do_one_initcall+0xf4/0x26c [ 240.240346] [] ? trace_hardirqs_on_thunk+0xc/0x10 [ 240.240959] [] ? restore_all+0xf/0xf [ 240.241420] [] kernel_init_freeable+0x491/0x62a [ 240.241990] [] ? do_early_param+0x12b/0x12b [ 240.242531] [] kernel_init+0x19/0x1f6 [ 240.243013] [] ? schedule_tail+0x1a/0xa9 [ 240.243517] [] ret_from_kernel_thread+0x20/0x30 [ 240.244076] [] ? rest_init+0x1dd/0x1dd [ 240.244565] 5 locks held by swapper/1: [ 240.244959] #0: (&dev->mutex){......}, at: [] device_lock+0x1b/0x2b [ 240.245769] #1: (&dev->mutex){......}, at: [] device_lock+0x1b/0x2b [ 240.246599] #2: (drm_global_mutex){......}, at: [] drm_dev_register+0x24/0x1f4 [ 240.247513] #3: (&dev->mode_config.mutex){......}, at: [] drm_fb_helper_initial_config+0x2bb/0x78e [ 240.248628] #4: (&dev->mode_config.mutex){......}, at: [] drm_modeset_lock_all+0x23/0x80 [ 240.249627] sending NMI to all CPUs: [ 240.250023] NMI backtrace for cpu 0 [ 240.250387] CPU: 0 PID: 8 Comm: khungtaskd Not tainted 3.15.0-rc5-00087-gb739c99 #1 [ 240.251155] task: d35d0410 ti: d35f8000 task.ti: d35f8000 [ 240.251694] EIP: 0060:[] EFLAGS: 00000046 CPU: 0 [ 240.252263] EIP is at native_apic_mem_write+0x20/0x30 [ 240.252623] EAX: ffffb300 EBX: 00000201 ECX: fffff000 EDX: 00000c00 [ 240.252623] ESI: 00000002 EDI: 01000000 EBP: d35f9e9c ESP: d35f9e9c [ 240.252623] DS: 007b ES: 007b FS: 0000 GS: 0000 SS: 0068 [ 240.252623] CR0: 8005003b CR2: 00000000 CR3: 11ec1000 CR4: 000006d0 [ 240.252623] Stack: [ 240.252623] d35f9eb4 c1045a5c 00000800 00000246 00000001 00000000 d35f9ed0 c1045f92 [ 240.252623] 00000002 00000000 00000002 d3422000 d3422000 d35f9ed8 c1045fee d35f9ee8 [ 240.252623] c10462cd c2d5dce2 00000002 d35f9f30 c111fecf c2d6bb8b c3480e6c c2ef6456 [ 240.252623] Call Trace: [ 240.252623] [] __default_send_IPI_dest_field+0xec/0x100 [ 240.252623] [] default_send_IPI_mask_logical+0x16c/0x17d [ 240.252623] [] default_send_IPI_all+0x38/0x94 [ 240.252623] [] arch_trigger_all_cpu_backtrace+0xc5/0x1b8 [ 240.252623] [] watchdog+0x55d/0x61a [ 240.252623] [] ? rcu_read_lock+0x81/0x81 [ 240.252623] [] kthread+0x115/0x128 [ 240.252623] [] ? lock_release+0x3ca/0x48a [ 240.252623] [] ret_from_kernel_thread+0x20/0x30 [ 240.252623] [] ? __kthread_unpark+0x9b/0x9b [ 240.252623] Code: 83 15 f4 db 46 c3 00 89 c8 5d c3 55 89 e5 83 05 08 dc 46 c3 01 83 15 0c dc 46 c3 00 8b 0d 74 bd f1 c2 8d 84 08 00 c0 ff ff 89 10 <83> 05 10 dc 46 c3 01 83 15 14 dc 46 c3 00 5d c3 55 89 e5 09 c8 git bisect start 5dba024fe84a491ec3ca15193923fcbb938e68f7 fad01e866afdbe01a1f3ec06a39c3a8b9e197014 -- git bisect good 12072cdd5c9b56bb6d4169c5a52c9d0bf64b7f84 # 12:32 20+ 0 Merge 'gxt/unicore32' into devel-hourly-2014060210 git bisect good eb1a12ad1d5a7312a6f3dc6a8b77c51cbe58641e # 12:42 20+ 0 Merge 'luto/auditsc-lite' into devel-hourly-2014060210 git bisect good d641155270aff21eacd2622e30129cd91fe8d2d2 # 12:51 20+ 0 Merge 'wsa/i2c/for-next' into devel-hourly-2014060210 git bisect good 002fa82dac6f0be486333e6424968c0c42c0e799 # 13:01 20+ 0 Merge 'jbarnes/async' into devel-hourly-2014060210 git bisect bad 1ea52a9605be1234b7da3e4d134917c7ba3be93d # 13:15 0- 5 Merge 'jbarnes/async-fb-probe' into devel-hourly-2014060210 git bisect bad f728080d6bac47aab2d570492acef88317ac8e03 # 13:41 0- 10 drm/i915: make fbdev initialization asynchronous v2 git bisect bad b739c9982801e5f76097311b67dfd76891b10988 # 13:50 0- 11 drm: take modeset locks around initial fb helper probing # first bad commit: [b739c9982801e5f76097311b67dfd76891b10988] drm: take modeset locks around initial fb helper probing git bisect good 071f9c57eea4876288ba1254c9ac3b0f077c2dd6 # 14:01 60+ 1 drm/i915/vlv: enable PPGTT git bisect bad 5dba024fe84a491ec3ca15193923fcbb938e68f7 # 14:01 0- 13 0day head guard for 'devel-hourly-2014060210' git bisect good fad01e866afdbe01a1f3ec06a39c3a8b9e197014 # 14:08 60+ 0 Linux 3.15-rc8 git bisect good 322c030f5462a44ce42f8804284eb52b7cd2ba41 # 14:25 60+ 60 Add linux-next specific files for 20140530 This script may reproduce the error. ----------------------------------------------------------------------------- #!/bin/bash kernel=$1 initrd=yocto-minimal-i386.cgz wget --no-clobber https://github.com/fengguang/reproduce-kernel-bug/blob/master/initrd/$initrd kvm=( qemu-system-x86_64 -cpu kvm64 -enable-kvm -kernel $kernel -initrd $initrd -smp 2 -m 256M -net nic,vlan=0,macaddr=00:00:00:00:00:00,model=virtio -net user,vlan=0 -net nic,vlan=1,model=e1000 -net user,vlan=1 -boot order=nc -no-reboot -watchdog i6300esb -serial stdio -display none -monitor null ) append=( debug sched_debug apic=debug ignore_loglevel sysrq_always_enabled panic=10 prompt_ramdisk=0 earlyprintk=ttyS0,115200 console=ttyS0,115200 console=tty0 vga=normal root=/dev/ram0 rw ) "${kvm[@]}" --append "${append[*]}" ----------------------------------------------------------------------------- Thanks, Fengguang