From: Ingo Molnar <mingo@elte.hu>
To: Serge Noiraud <serge.noiraud@bull.net>
Cc: linux-kernel <linux-kernel@vger.kernel.org>
Subject: Re: PREEMPT_RT and latency_trace
Date: Mon, 11 Jul 2005 07:03:03 +0200 [thread overview]
Message-ID: <20050711050303.GA13190@elte.hu> (raw)
In-Reply-To: <1120826951.6225.167.camel@ibiza.btsn.frna.bull.fr>
* Serge Noiraud <serge.noiraud@bull.net> wrote:
> Hi,
>
> I have a big dilemna on one machine :
> I run a task with RT priority which make a loop to mesure the system
> perturbation.
> It works well except on one machine.
> On a multi-cpu, If I run the program on cpu 1, I get 23us. It's OK.
> If I run the same program on cpu 0, I get 17373us !
could you try the -51-24 (or later) kernel, does it have any better
latencies? It has a PI fix that fixes the recent priority leakage
observed on SMP systems. The priority leakage can lead to excessive
delays in RT apps.
Ingo
prev parent reply other threads:[~2005-07-11 5:03 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2005-07-08 12:49 PREEMPT_RT and latency_trace Serge Noiraud
2005-07-08 13:40 ` Daniel Walker
2005-07-08 13:58 ` Ingo Molnar
2005-07-11 5:03 ` Ingo Molnar [this message]
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