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    SubjectRe: Incorrect CLOCK_TICK_RATE in 2.6 kernel
    john stultz wrote:
    > On Wed, 2005-08-24 at 17:24 -0700, George Anzinger wrote:
    >>CLOCK_TICK_RATE is used by the kernel to compute LATCH, TICK_NSEC and
    >>tick_nsec. This latter is used to update xtime each tick. TICK_NSEC is
    >>then used to compute (at compile time) the conversion constants needed
    >>to convert to/from jiffies from/to timespec and timeval (and others).
    >>The problem is that, if the timer being used is either Cyclone or HPET,
    >>the wrong CLOCK_TICK_RATE is used.
    > Err, the Cyclone does not generate interrupts. So this issue does not
    > affect those systems.
    > As for the HPET, it sets its own interrupt frequency based off of
    > KERNEL_TICK_USEC (which you're right, isn't quite what is used in the
    > jiffies conversions). Would it be easier to just adjust that value to

    If you want to take that approach you would want the HPET to interrupt
    every TICK_NSEC nanoseconds, that being what xtime is pushed by each tick.

    George Anzinger
    HRT (High-res-timers):
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      Last update: 2005-08-25 03:33    [W:0.023 / U:0.836 seconds]
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