Re: [suse-amd64] False "lost ticks" on dual-Opteron system (=> timer twice as fast)

[Bernd Paysan]

On Monday 09 May 2005 12:53, Bernd Paysan wrote:
> On Sunday 08 May 2005 15:40, Andi Kleen wrote:
> > Your system should be using the HPET timer to work exactly around
> > this. AMD 8000 has HPET. Can you post a boot.log?
>
> Ok, boot.log attached. The only entry with hpet seems to indicate some
> problems.

I went through the BIOS setup, and found a disabled feature "ACPI 2.0", 
which I enabled. Now Linux finds the HPET timer.

# grep -i hpet boot.log 
ACPI: HPET (v001 A M I  OEMHPET  0x04000518 MSFT 0x00000097) @ 
0x00000000e8ff3c30
ACPI: HPET id: 0x102282a0 base: 0xfec01000
time.c: Using 14.318180 MHz HPET timer.
time.c: Using HPET based timekeeping.
hpet0: at MMIO 0xfec01000, IRQs 2, 8, 0
hpet0: 69ns tick, 3 32-bit timers
hpet_acpi_add: no address or irqs in _CRS

and everything appears to work (though there's still no designated CPU to 
handle the timer interrupts). xntpd syncs quickly, I'm happy (so far ;-).

So that explains why nobody sees this problem. But the TSC-based fallback 
timekeeping is still broken on SMP systems with PowerNow and distributed 
IRQ handling, which both together seem to be rare enough ;-).

-- 
Bernd Paysan
"If you want it done right, you have to do it yourself"
http://www.jwdt.com/~paysan/

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