Re: TSC instead of ACPI: powerd doesn't work anymore (to be expected?)

From: Poul-Henning Kamp (phk_at_phk.freebsd.dk)
Date: 10/31/05

  • Next message: Robert Watson: "Re: TSC instead of ACPI: powerd doesn't work anymore (to be expected?)" 
    To: David Xu <davidxu@freebsd.org>
Date: Mon, 31 Oct 2005 11:26:38 +0100

    In message <4365EF7B.1020706@freebsd.org>, David Xu writes:
    >Robert Watson wrote:
    >>
    >>
    >> It has been suggested that the former can operate quite well with
    >> significantly reduced quality. It has alos been suggested that most
    >> applications could operate fine with somewhat reduced quality, but that
    >> the API definitions don't say anything about how to specify application
    >> quality requirements vs performance requirements for time measurement.
    >
    >Can we change gettimeofday and clock_gettime to lower resolution now?

    I can live with gettimeofday(2) and time(3) being degraded.

    I am going to insist that clock_gettime(CLOCK_REALTIME, CLOCK_UPTIME)
    remain precise.

    >I think 1000hz/s is enough for most applications, since a thread can
    >never sleep shorter than a tick for years.

    (Famous last words!)

    Time is not just a matter of sleeping.

    >We can introduce
    >hrtime_t clock_gethrtime(clockid_t clock) to get hi-resolution time
    >as the one seen in RTLinux, or gethrtime() as seen in Solaris (Daniel
    >Eischen said?)

    You know ?

    This is just a great example of why people feel the autocrap tools
    is the way to write portable code :-(

    The open group specifically allow clock_gettime() to implement
    more timescales, so what did those fools go and invent even more
    library functions for ?

    Poul-Henning 

    -- 
Poul-Henning Kamp       | UNIX since Zilog Zeus 3.20
phk@FreeBSD.ORG         | TCP/IP since RFC 956
FreeBSD committer       | BSD since 4.3-tahoe    
Never attribute to malice what can adequately be explained by incompetence.
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  • Next message: Robert Watson: "Re: TSC instead of ACPI: powerd doesn't work anymore (to be expected?)"