Re: Boot hang after io scheduler registration

[Andrew Morton <akpm@linux-foundation.org>]

On Sat, 27 Dec 2008 00:35:19 +0100 Kai Ruhnau <kai@tragetaschen.dyndns.org> wrote:

> Hi,
> 
> I have a somewhat weird hang problem when booting all recent kernel
> versions including 2.6.28: When I boot my system and let grub start the
> kernel after a 5 second timeout, the system will hang after registering
> the io schedulers (see below). However, when I choose the default grub
> entry manually by pressing ENTER in the menu, the kernel does not hang
> and continues the normal booting process.
> 
> Below, you can find the place of the hang and an excerpt of the messages
> that follow on a normal boot as well as some system information.
> 
> Thanks for your time on this problem.
> 
> Best regards
> Kai
> 
> # dmesg
> ...
> [    0.309379] io scheduler noop registered
> [    0.309473] io scheduler anticipatory registered
> [    0.309569] io scheduler deadline registered
> [    0.309679] io scheduler cfq registered (default)
> 
> Hang happens here.
> 
> Continuation when pressing ENTER in grub:
> 
> [    0.414098] pci 0000:01:00.0: Boot video device
> [    0.417068] pcieport-driver 0000:00:02.0: setting latency timer to 64
> [    0.417097] pcieport-driver 0000:00:02.0: found MSI capability
> [    0.417222] pcieport-driver 0000:00:02.0: irq 319 for MSI/MSI-X
> [    0.417231] pci_express 0000:00:02.0:pcie00: allocate port service
> [    0.417294] pci_express 0000:00:02.0:pcie03: allocate port service
> [    0.417376] pcieport-driver 0000:00:06.0: setting latency timer to 64
> [    0.417403] pcieport-driver 0000:00:06.0: found MSI capability
> [    0.417523] pcieport-driver 0000:00:06.0: irq 318 for MSI/MSI-X
> [    0.417532] pci_express 0000:00:06.0:pcie00: allocate port service
> [    0.417580] pci_express 0000:00:06.0:pcie03: allocate port service
> ...
> 

Please add `initcall_debug' to the kernel boot command line.  That
should tell us which initialisation function is getting stuck.