[ntp:questions] Re: announce: PPSkit-2.1.2 for Linux 2.4.21
David L. Mills
mills at udel.edu
Thu Sep 4 03:11:26 UTC 2003
Not all. The nanokernel for Digital [!!] Alpha SMP was intricately
engineered to prosper using multiple PCC (TSC) disciplined to the kernel
time variable. This little bit of proprietary nonsense might not be
easily apparent in the distribution that left here, but I don't think it
has been widely copied outside of the Tru64 kernel.
Terje Mathisen wrote:
> Piotr Trojanek wrote:
> > In article <m37k4qmhh9.fsf at pc5234.rz.uni-regensburg.de>, Ulrich Windl wrote:
> >>I would like to have any feedback regarding architectures other than
> >>ia32/Pentium. The download can be found on up-to-date Linux mirrors
> >>in /pub/linux/daemons/ntp/PPS as PPSkit-2.1.2.tar.gz (or bz2). The
> >>size is about 125kB.
> > What are the reasons Linux use TSC for PPS timestamping, while
> > FreeBSD-5.1-RELEASE use ACPI (by default)? -- I don't say ACPI is
> > better, just asking.
> TSC is mostly useless on SMP machines unfortunatly, unless you can pin
> your process, including all PPS interrupt handlers, to a single CPU.
> - <Terje.Mathisen at hda.hydro.com>
> "almost all programming can be viewed as an exercise in caching"
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