In message <[EMAIL PROTECTED]>, Jim Bryant writes:
>since there is only a single master clock oscillator, there really
>should be no frequency difference between CPUs.
As long it runs constantly: yes. As soon as you have clock-stop
events you will have different resync times for the on-chip PLL
...
> > One question comes to mind: is there a way that the TSCs could become
> > desynchronized somehow? Even though all CPUs run at the same frequency,
> > isn't there a strong possibility for slight frequency deviation since
> > we use crystal oscillation instead of a more accurate atomic brea
In reply:
> On Tue, 21 Sep 1999, Luoqi Chen wrote:
>
> > This reminds me about the usage of TSC counter on SMP. First even though
> > we don't use TSC for time keeping on SMP, the TSC frequency from calibration
> > is still valid (at least for BSP), and we can show it in the cpu identification
>
In message <[EMAIL PROTECTED]>, Luoqi Chen writes:
>> people have found sufficiently many cases where the counters are
>> not in sync after the BIOS is done.
>>
>I would really like to know how they managed to read the TSCs simultaneously,
>or they resorted to some kind of statistical means (whi
> >TSC is initialized to 0 at hardware reset, which should happen to all CPUs
> >at the same time (invalid assumption?), in another words, all TSCs should be
> >automatically synchronized.
>
> They are not. The PLL is local to each cpu and every single
> clock-stop/start event has then inching a
In message <[EMAIL PROTECTED]>, Luoqi Chen writes:
>Second, the listed reason for not using TSC on SMP is the inability
>to synchronize TSCs on all cpus. My question is, is it really necessary?
Strictly speaking no, it isn't necessary, but unless they are in sync
the timekeeping code gets very c
> One question comes to mind: is there a way that the TSCs could become
> desynchronized somehow? Even though all CPUs run at the same frequency,
> isn't there a strong possibility for slight frequency deviation since
> we use crystal oscillation instead of a more accurate atomic breakdown
> for
On Tue, 21 Sep 1999, Luoqi Chen wrote:
> This reminds me about the usage of TSC counter on SMP. First even though
> we don't use TSC for time keeping on SMP, the TSC frequency from calibration
> is still valid (at least for BSP), and we can show it in the cpu identification
> message. Second, the
> If you have a PIIX4 based SMP system and run current, could you
> please try out this patch:
>
> http://phk.freebsd.dk/piix/
>
> I'm very interested in hearing if there are any measurable difference
> apart from clock granularity being 3 times better.
>
> --
> Poul-Henning Kamp
In reply:
> If you have a PIIX4 based SMP system and run current, could you
> please try out this patch:
>
> http://phk.freebsd.dk/piix/
>
> I'm very interested in hearing if there are any measurable difference
> apart from clock granularity being 3 times better.
just cvsupped, added your
In message <[EMAIL PROTECTED]>, Peter Wemm writes
:
>Poul-Henning Kamp wrote:
>>
>> Ok, noted. I changed to to fail the probe but still use the hardware.
>
>If intpm is probed first (the smbus driver), your probe won't even get
>called. I think we need an early quirks or hooks handler in the pci
Poul-Henning Kamp wrote:
>
> Ok, noted. I changed to to fail the probe but still use the hardware.
If intpm is probed first (the smbus driver), your probe won't even get
called. I think we need an early quirks or hooks handler in the pci probes
to handle stuff like this. For example, we have h
Ok, noted. I changed to to fail the probe but still use the hardware.
Poul-Henning
In message <[EMAIL PROTECTED]>, Peter Wemm writes
:
>Poul-Henning Kamp wrote:
>>
>> If you have a PIIX4 based SMP system and run current, could you
>> please try out this patch:
>>
>> http://phk.freebsd.d
Poul-Henning Kamp wrote:
>
> If you have a PIIX4 based SMP system and run current, could you
> please try out this patch:
>
> http://phk.freebsd.dk/piix/
>
> I'm very interested in hearing if there are any measurable difference
> apart from clock granularity being 3 times better.
There i
In message <[EMAIL PROTECTED]>, Dav
id Scheidt writes:
>On Sun, 19 Sep 1999, Poul-Henning Kamp wrote:
>
>>
>> If you have a PIIX4 based SMP system and run current, could you
>> please try out this patch:
>>
>> http://phk.freebsd.dk/piix/
>>
>> I'm very interested in hearing if there are an
On Sun, 19 Sep 1999, Poul-Henning Kamp wrote:
>
> If you have a PIIX4 based SMP system and run current, could you
> please try out this patch:
>
> http://phk.freebsd.dk/piix/
>
> I'm very interested in hearing if there are any measurable difference
> apart from clock granularity being 3
If you have a PIIX4 based SMP system and run current, could you
please try out this patch:
http://phk.freebsd.dk/piix/
I'm very interested in hearing if there are any measurable difference
apart from clock granularity being 3 times better.
--
Poul-Henning Kamp FreeBSD coret
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