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    SubjectRe: [suse-amd64] False "lost ticks" on dual-Opteron system (=> timer twice as fast)
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    On Monday 09 May 2005 09:17, Bernd Paysan wrote:
    > 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 ;-).

    Maybe on UP too:

    May 8 18:50:25 grover kernel: [143640.507170] Attached scsi removable disk sda at scsi5, channel 0, id 0, lun 0
    May 8 18:50:25 grover kernel: [143640.520422] rtc: lost some interrupts at 1024Hz.
    May 8 18:50:25 grover kernel: [143640.554134] Attached scsi generic sg0 at scsi5, channel 0, id 0, lun 0, type 0
    May 8 18:50:25 grover kernel: [143640.567693] rtc: lost some interrupts at 1024Hz.
    May 8 18:50:25 grover kernel: [143640.596402] usb-storage: device scan complete

    This from 12-rc3-mm3, UP x86_64 with powernow active.

    It might be that the message is OK here since I do not see a fast clock. I mention this
    since powernow is active here.

    Should HPET be available in UP?

    Ed Tomlinson

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