Re: [PATCH] x86-64 highres/dyntick support

[Thomas Gleixner <tglx@linutronix.de>]

Alistair,

On Mon, 2007-05-14 at 02:17 +0100, Alistair John Strachan wrote:
> I've noticed a few problems with this patch series, which I manually (without 
> difficulty) ported to 2.6.22-rc1.

There are a couple of fixups pending. I'm going to push out a new queue
today.

> Only 195 timer interrupts? I only see this on an AMD Opteron, it doesn't occur 
> on an Intel Core 2 Duo. Mainline reports this counter regularly increasing 
> with or without the acpi_pm clocksource loaded.

We stop the PIT when we switch to the local APICs. On your Intel box you
might have deeper C-states which switch the system back to broadcast
mode via PIT.

> Secondly, /proc/cpuinfo seems to be broken:
> 
> alistair@damocles:~$ cat /proc/cpuinfo | grep MHz
> cpu MHz         : 210779.550
> cpu MHz         : 210779.550
> 
> Unless my CPU is just under 80 times faster than it used to be, these numbers 
> are incorrect. I expect 2700.50, or something similar. cpufreq isn't compiled 
> in.

Hmm. It seems the new TSC calibration routine is hosed.

> Finally, and possibly related, the dmesg timestamps seem to be totally broken. 
> Apparently my machine booted in less than 1 second, with the last messages 
> as:
> 
> [    0.607862] bridge: topology change detected, propagating
> [    0.607862] bridge: port 2(lan-sky) entering forwarding state
> [    0.830472] Linux agpgart interface v0.102 (c) Dave Jones

Hey, you have a really fast box :)

	tglx