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    SubjectRe: No 100 HZ timer !
    On Tue, Apr 10, 2001 at 12:18:03PM +0100, Alan Cox wrote:
    > > > interrupting decrementer. (i.e just about any modern chip)
    > >
    > > Just how would you do kernel/user CPU time accounting then ? It's currently done
    > > on every timer tick, and doing it less often would make it useless.
    >
    > On the contrary doing it less often but at the right time massively improves
    > its accuracy. You do it on reschedule. An rdtsc instruction is cheap and all
    > of a sudden you have nearly cycle accurate accounting

    Does not sound very attractive all at all on non virtual machines (I see the point on
    UML/VM):
    making system entry/context switch/interrupts slower, making add_timer slower, just to
    process a few less timer interrupts. That's like robbing the fast paths for a slow path.

    -Andi
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