Re: [patch] Real-Time Preemption, -VP-2.6.9-rc4-mm1-U4

From: Ingo Molnar (mingo_at_elte.hu)
Date: 10/16/04

  • Next message: Adam Heath: "Re: [patch] Real-Time Preemption, -VP-2.6.9-rc4-mm1-U4"
    Date:	Sat, 16 Oct 2004 21:36:26 +0200
    To: Adam Heath <doogie@debian.org>
    
    

    * Adam Heath <doogie@debian.org> wrote:

    > > i have released the -U4 PREEMPT_REALTIME patch:
    > >
    > > http://redhat.com/~mingo/voluntary-preempt/voluntary-preempt-2.6.9-rc4-mm1-U4
    > >
    > > this is a fixes-only release, and it is still experimental code.
    >
    > Few stack dumps now.

    these are normal, they are the PREEMPT_TIMING traces which get printed
    every time the kernel measures a new latency maximum. The stack dumps
    are done to make it easier to identify which place too that long of a
    delay and why. (if LATENCY_TRACE is enabled too then the last latency
    and its trace can also be found in /proc/latency_trace.)

    after bootup it makes sense to reset the maximum:

            echo 10 > /proc/sys/kernel/preempt_max_latency

    because during bootup there are a number of latencies that are one-time
    only.

            Ingo
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  • Next message: Adam Heath: "Re: [patch] Real-Time Preemption, -VP-2.6.9-rc4-mm1-U4"

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