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    SubjectRe: PREEMPT_RT vs ADEOS: the numbers, part 1
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    On Sun, 2005-06-12 at 16:54 +0200, Ingo Molnar wrote:
    > * James R Bruce <bruce@andrew.cmu.edu> wrote:
    >
    > > Ingo, if you could document the right options required for decent
    > > performace somewhere it would be quite helpful (maybe in
    > > Documentation/rt-preempt?). My first test of Preempt-RT showed
    > > unexpectedly high overhead for a fairly benign network load (120 UDP
    > > packets/sec), but that was likely the result of leaving some debugging
    > > options on.
    >
    > agreed, this needs to be addressed.
    >
    > in the latest patch (-48-17 or later) i have changed the debugging
    > options to default to off. (this wont turn them off if your .config has
    > them turned on already, but will turn them off for new testers'
    > .configs)
    >
    > I also added a prominent boot-time message that, if certain
    > high-overhead debugging options are enabled, says:
    >
    > *****************************************************************************
    > * *
    > * WARNING, the following debugging options are turned on in your .config: *
    > * *
    > * CONFIG_DEBUG_RT_LOCKING_MODE *
    > * CONFIG_RT_DEADLOCK_DETECT *
    > * CONFIG_DEBUG_PREEMPT *
    > * CONFIG_CRITICAL_PREEMPT_TIMING *
    > * CONFIG_CRITICAL_IRQSOFF_TIMING *
    > * CONFIG_LATENCY_TRACE *
    > * CONFIG_DEBUG_SLAB *
    > * *
    > * they may increase runtime overhead and latencies considerably! *
    > * *
    > *****************************************************************************
    >
    > wrt. documentation - i'm not a big doc writer, but i'm taking patches
    > :-)
    >
    > Ingo

    Thanks, that will help us getting better results from PREEMPT_RT.

    Kristian

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