Re: [discuss] Re: 2.6.15-rc5-mm1 (x86_64-hpet-overflow.patch breaks resume from disk)

Andi Kleen
2005-12-08T22:47:40Z

On Thu, Dec 08, 2005 at 09:43:52AM +0100, Jan Beulich wrote:
> I don't know how resume normally handles the re-syncing of the wall
> clock, but the problem here is obvious: do_timer runs a loop to
> increment jiffies, which may require significant amounts of time
> (depending how long the system was sleeping).

It would be good if someone could submit a patch to fix
this up properly. It indeed sounds wrong.

The HPET patch seems to be generally unhappy. With it applied
I get lots of obviously wrong softlockup warnings from the
softlockup watchdog thread on a dual NForce4 system. So something
goes wrong with the timing there. The strange thing
is that the system doesn't even have a HPET table so HPET code shouldn't
be executed - but it goes away when I revert the patch. Very
mysterious.

Also I think vgettimeofday doesn't handle 64bit HPET correctly
yet. Also why does it not use hpet_readq?

I suspect the 64bit HPET patch needs some more cooking. I think
I will drop it for now.

I would suggest you submit the cleanups in there separately
(without changing semantics yet)
then it will be easier to test in the future too.

-Andi