NO JOY Boot hangs 5 minute at "Switching to clockwork tsc" line

[Brian Simmons]

I have installed a PIAF Green 2.11 (everything is latest version - downloaded and installed yesterday) on a machine that wasn't being used at the office. It is a beast of a machine, and total overkill for this application, but it made more sense to use it than buying a slower machine to use.

The installation process went fine. But now when I reboot, the process hangs up on a line, "Switching to clockwork TSC" for about 5 minutes. If left long enough, it will eventually continue on and finish the booting process just fine.

I'm no Linux expert. In fact, my linux exposure is extremely limited. I'd love some help to figure out what is going on and how to fix it.

PS - I turned off any overclocking or memory boosting in the BIOS thinking it might cause an issue, but that did not help prevent the hang.

Thanks,

Brian

 

[randy7376]

Brian Simmons

You might want to check out this thread. It deals with a different problem, but I have details in it on how to check for available clock sources and change the default. The tsc (time-stamp counter) clock source has given me grief in the past.

 

[Brian Simmons]

I added the "clocksource=tsc" command to the end of the kernel line in the grub.conf file.

Now when it boots, I get this line "Overriding clocksource tsc is not HRT compatible. Cannot switch while in HRT/NOHZ mode"
the next line is the same "Switching to clockwork tsc" as before and results in the 5 min hang.

Am I putting the command in the right place? Any other suggestions? Thanks!

 

[randy7376]

Brian Simmons

Well, since you seem to be having problems with tsc, you should probably try a different clock source. I believe you're seeing the reason WHY your system is hanging on the tsc clock source.

What does the output of cat /sys/devices/system/clocksource/clocksource0/available_clocksource give you?

If hpet or acpi_pm is available, try those and see if your system still hangs at boot up. hpet would be preferable.

Given that you're getting "Overriding clocksource tsc is not HRT compatible. Cannot switch while in HRT/NOHZ mode", even this may not work. What kind of server hardware are you using?

 

[Brian Simmons]

Just an update on this....

I tried adding the "clocksource=tsc", "clocksource=hpet", and "clocksource=acpi_pm" to the end of the kernel line in the /boot/grub/grup.conf file (one at a time obviously) but to no avail. The boot process still hangs on a line that says "Switching to Clockwork TSC" for a few minutes. Eventually the boot process does continue and everything seems to work just fine. But if anyone else has any ideas, I'd like to try and get the boot process to work without hanging. It will be annoying if it takes 5 minutes to reboot the system should it go down or be restarted for some reason.

 

[Baylink]

Well, I'm now installing a 3.0, on a Core2Extreme (which is extreme overkill, but all I had handy), and I'm getting the same problem, though after 5 minutes, I came back and the screen was blank, rather than an install running. Brian Simmons: did you ever find a solution?

(In my case, since the install never actually starts, I can't get to where I could modify a file, though I just spotted how to edit the bootline; lemme try that)

 

[Baylink]

Alas, adding "clocksource=hpet" to the bootline only makes it hang one line of output earlier, right after it "refines the TSC clocksource calibration".

This is properly a CentOS problem; I'll go look there, though I'll cheerfully accept any pointers.

 

[Baylink]

BINGO:

http://www.clearfoundation.com/comp...Itemid,232/catid,37/func,view/id,52477/#52765

Fixed this for me, though 31a wasn't the best choice of video

 

[wardmundy]

Reminds me of...

 

[Baylink]

Quite so.

And, just in case that link ever dies, the solution is to add

ipmi_si.trydefaults=0

To your bootstring, either interactively, or in your grub configuration file.