Re: 2.6.23.1: Random hangs during boot with "tsc" clocksource

[Jordan Russell <jr-list-2007@quo.to>]

>> On Fri, 02 Nov 2007 12:10:00 -0500 Jordan Russell <jr-list-2007@quo.to> wrote:
>> Hi,
>>
>> With 2.6.23.1 (stock and Fedora), roughly 50% of the time my system
>> hangs indefinitely during the kernel boot process. The hangs occur in
>> places where normally a brief delay is seen, such as when detecting
>> serial ports, ATA devices, and USB hubs. SysRq+W, when it works, shows
>> tasks stuck inside schedule_timeout and lock_timer_base.
>>
>> I've found, however, that if I override the default "tsc" clocksource
>> with "acpi_pm" by adding "clocksource=acpi_pm" to the kernel command
>> line, the system comes up fine every time. (Zero hangs in ~50 tries.)
>>
>> I never had to do this with stock kernels based on 2.6.22.10 and
>> earlier, which also defaulted to "tsc" on my system.
>>
>> I came across this thread:
>>   http://lkml.org/lkml/2007/10/16/339
>> but I'm not sure if it's the same issue. I've never seen a "Clocksource
>> tsc unstable" message, and the kernel doesn't appear to unwedge itself
>> after 5 minutes (I waited 20 minutes once).

[... snip cpuinfo, dmesg, config ...]

Same problem with 2.6.23.8.

Are there any specific (TSC related?) patches I should try reverting?

Would it help if I captured the dmesg/SysRq output from one of the
hanging boots?

Any other information that might be useful in getting to the bottom of this?

Thanks.
Jordan Russell