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    SubjectRe: -mm -> 2.6.13 merge status
    On 6/21/05, Lee Revell <rlrevell@joe-job.com> wrote:
    > On Mon, 2005-06-20 at 23:54 -0700, Andrew Morton wrote:
    > > CONFIG_HZ for x86 and ia64: changes default HZ to 250, make HZ
    > > Kconfigurable.
    > >
    > > Will merge (will switch default to 1000 Hz later if that seems
    > > necessary)
    >
    > Are you serious? You're changing the *default* HZ in a stable kernel
    > series?!?
    >
    > This is a big regression, it degrades the resolution of system calls.

    Not that my opinion should sway anybody else, but I really would
    prefer more of the in-kernel sleep callers were converted to use
    human-time units (and thus were verified to be correct) so that
    switching HZ will result in the *same* latencies. How much of moving
    to lower HZ values is due to the fact that everything is request 10ms
    for 1 jiffy of sleep instead of 1 ms? It's hard to tell if the gain is
    there or from the lower frequency of interrupts.

    I've sent out a lot of patches in this direction (using msleep() and
    msleep_interruptible() and my soft-timer rework on top of John
    Stultz's timeofday rework converts the entire soft-timer subsystem to
    use human-time instead of jiffies as it's unit of expiration), but
    there is still *a lot* of work left to do :( I will keep sending
    patches, but am being pulled in other directions currently.

    Just my $.02.

    Thanks,
    Nish
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