Fw: Kernel Loading Sequence

[drago01]

On Sun, Jul 12, 2009 at 10:50 AM, Ahmad Al-Yaman<ahmad221284 at yahoo.com> wrote:
> I was able to find out the messages that are displayed before plymouth starts, but I still have no idea what's causing them:
>
> [ INFO: possible circular locking dependency detected ]
> 2.6.29.5-191.eeepc.fc11.i686.PAE #1
> -------------------------------------------------------
> plymouthd/746 is trying to acquire lock:
>  (&fb_info->lock){--..}, at: [<c05288bc>] fb_mmap+0x83/0x153
>
> but task is already holding lock:
>  (&mm->mmap_sem){----}, at: [<c0406a3c>] sys_mmap2+0x44/0x7b
>
> which lock already depends on the new lock.
>
>
> the existing dependency chain (in reverse order) is:
>
> -> #3 (&mm->mmap_sem){----}:
>       [<c04463fa>] __lock_acquire+0x1068/0x137e
>       [<c044676e>] lock_acquire+0x5e/0x7a
>       [<c046ddb4>] might_fault+0x68/0x88
>       [<c0510de3>] copy_to_user+0x2f/0x106
>       [<c0489920>] filldir+0x80/0xbb
>       [<c04b8a3d>] sysfs_readdir+0x104/0x138
>       [<c0489a99>] vfs_readdir+0x68/0x94
>       [<c0489bd2>] sys_getdents+0x60/0xa4
>       [<c0403202>] syscall_call+0x7/0xb
>       [<ffffffff>] 0xffffffff
>
> -> #2 (sysfs_mutex){--..}:
>       [<c04463fa>] __lock_acquire+0x1068/0x137e
>       [<c044676e>] lock_acquire+0x5e/0x7a
>       [<c07c919f>] mutex_lock_nested+0xe0/0x267
>       [<c04b8cf4>] sysfs_addrm_start+0x23/0x95
>       [<c04b919d>] create_dir+0x3a/0x76
>       [<c04b9206>] sysfs_create_dir+0x2d/0x3d
>       [<c050c198>] kobject_add_internal+0xaa/0x159
>       [<c050c2ee>] kobject_add_varg+0x31/0x3d
>       [<c050c364>] kobject_add+0x43/0x49
>       [<c05ad349>] device_add+0x79/0x3fb
>       [<c05ad6dd>] device_register+0x12/0x15
>       [<c05ad757>] device_create_vargs+0x77/0xa0
>       [<c05ad79b>] device_create+0x1b/0x1d
>       [<c056f49e>] register_con_driver+0xdd/0x137
>       [<c0570637>] take_over_console+0x14/0x35
>       [<c0532c59>] fbcon_takeover+0x5f/0x92
>       [<c053336f>] fbcon_event_notify+0x3b7/0x726
>       [<c043ab5c>] notifier_call_chain+0x51/0x78
>       [<c043ad1d>] __blocking_notifier_call_chain+0x37/0x4c
>       [<c043ad3e>] blocking_notifier_call_chain+0xc/0xe
>       [<c05283fd>] fb_notifier_call_chain+0x11/0x13
>       [<c0529198>] register_framebuffer+0x1e2/0x1f3
>       [<c05a01b6>] intelfb_probe+0x491/0x4fb
>       [<c0586cc5>] drm_helper_initial_config+0x148/0x152
>       [<c05902b5>] i915_driver_load+0x8b2/0x912
>       [<c057fb7b>] drm_get_dev+0x343/0x405
>       [<c07b6741>] i915_pci_probe+0xd/0xf
>       [<c051aee2>] local_pci_probe+0xe/0x10
>       [<c051b84d>] pci_device_probe+0x46/0x69
>       [<c05aedd5>] driver_probe_device+0xa2/0x11d
>       [<c05aee9c>] __driver_attach+0x4c/0x6b
>       [<c05ae7f1>] bus_for_each_dev+0x3b/0x63
>       [<c05aec76>] driver_attach+0x14/0x16
>       [<c05ae28c>] bus_add_driver+0x98/0x1ab
>       [<c05af033>] driver_register+0x6f/0xd3
>       [<c051bb3d>] __pci_register_driver+0x46/0xa5
>       [<c057c3f4>] drm_init+0x5b/0xb3
>       [<c0a39544>] i915_init+0x46/0x48
>       [<c0401132>] _stext+0x4a/0x111
>       [<c0a1e386>] kernel_init+0x17f/0x1d0
>       [<c0403a37>] kernel_thread_helper+0x7/0x10
>       [<ffffffff>] 0xffffffff
>
> -> #1 ((fb_notifier_list).rwsem){..--}:
>       [<c04463fa>] __lock_acquire+0x1068/0x137e
>       [<c044676e>] lock_acquire+0x5e/0x7a
>       [<c07c98db>] down_read+0x2a/0x3e
>       [<c043ad0a>] __blocking_notifier_call_chain+0x24/0x4c
>       [<c043ad3e>] blocking_notifier_call_chain+0xc/0xe
>       [<c05283fd>] fb_notifier_call_chain+0x11/0x13
>       [<c0529198>] register_framebuffer+0x1e2/0x1f3
>       [<c05a01b6>] intelfb_probe+0x491/0x4fb
>       [<c0586cc5>] drm_helper_initial_config+0x148/0x152
>       [<c05902b5>] i915_driver_load+0x8b2/0x912
>       [<c057fb7b>] drm_get_dev+0x343/0x405
>       [<c07b6741>] i915_pci_probe+0xd/0xf
>       [<c051aee2>] local_pci_probe+0xe/0x10
>       [<c051b84d>] pci_device_probe+0x46/0x69
>       [<c05aedd5>] driver_probe_device+0xa2/0x11d
>       [<c05aee9c>] __driver_attach+0x4c/0x6b
>       [<c05ae7f1>] bus_for_each_dev+0x3b/0x63
>       [<c05aec76>] driver_attach+0x14/0x16
>       [<c05ae28c>] bus_add_driver+0x98/0x1ab
>       [<c05af033>] driver_register+0x6f/0xd3
>       [<c051bb3d>] __pci_register_driver+0x46/0xa5
>       [<c057c3f4>] drm_init+0x5b/0xb3
>       [<c0a39544>] i915_init+0x46/0x48
>       [<c0401132>] _stext+0x4a/0x111
>       [<c0a1e386>] kernel_init+0x17f/0x1d0
>       [<c0403a37>] kernel_thread_helper+0x7/0x10
>       [<ffffffff>] 0xffffffff
>
> -> #0 (&fb_info->lock){--..}:
>       [<c04460d9>] __lock_acquire+0xd47/0x137e
>       [<c044676e>] lock_acquire+0x5e/0x7a
>       [<c07c919f>] mutex_lock_nested+0xe0/0x267
>       [<c05288bc>] fb_mmap+0x83/0x153
>       [<c0473ab7>] mmap_region+0x21c/0x3ab
>       [<c0473e96>] do_mmap_pgoff+0x250/0x2a2
>       [<c0406a52>] sys_mmap2+0x5a/0x7b
>       [<c0403202>] syscall_call+0x7/0xb
>       [<ffffffff>] 0xffffffff
>
> other info that might help us debug this:
>
> 1 lock held by plymouthd/746:
>  #0:  (&mm->mmap_sem){----}, at: [<c0406a3c>] sys_mmap2+0x44/0x7b
>
> stack backtrace:
> Pid: 746, comm: plymouthd Not tainted 2.6.29.5-191.eeepc.fc11.i686.PAE #1
> Call Trace:
>  [<c07c7b14>] ? printk+0xf/0x11
>  [<c0445054>] print_circular_bug_tail+0xab/0xb6
>  [<c04460d9>] __lock_acquire+0xd47/0x137e
>  [<c05288bc>] ? fb_mmap+0x83/0x153
>  [<c044676e>] lock_acquire+0x5e/0x7a
>  [<c05288bc>] ? fb_mmap+0x83/0x153
>  [<c07c919f>] mutex_lock_nested+0xe0/0x267
>  [<c05288bc>] ? fb_mmap+0x83/0x153
>  [<c05288bc>] ? fb_mmap+0x83/0x153
>  [<c05288bc>] fb_mmap+0x83/0x153
>  [<c0473ab7>] mmap_region+0x21c/0x3ab
>  [<c0473e96>] do_mmap_pgoff+0x250/0x2a2
>  [<c0406a52>] sys_mmap2+0x5a/0x7b
>  [<c0403202>] syscall_call+0x7/0xb
>
> Any ideas what could be causing this and how to solve it?
>
> Ahmad

Thats a lockdep warning, please report it.
After that you can simply disable the lockdep checker in your kernel
config and you wont see them anymore.